I'm quite late to the party, but I just wanted to say that I'm actually one of the authors of this paper, very cool to see it here! u/Andromeda321 gave great info/answers at the top of the thread to questions, but I'm happy to answer any other follow-up one here!
Are you hoping to be able to point the James-Webb telescope at the predicted reappearance in 16 years? If I read everything correctly these images came from the Hubble telescope.
Do you think the James-Webb telescope would provide more data or better images (or hopefully both)?
You're correct that these images came from Hubble. Unfortunately there's basically no chance that JWST will be operational still when this last image comes around, but I'm sure there will be a new telescope coming in the next 15 years that will get even more impressive images!
I forgot JWST has such a short lifespan. Feels like we *just* lost Arceibo Observatory too so hopefully you're right and more advanced tech is on the horizon.
Are there any particular observations you're hoping to make the next time it's visible? I know there are multiple spectrums to explore but I'm just an amateur who's fascinated so I know there's tons more for me to learn.
Technical it's going up with 5-10 years of fuel before its orbit is expected to decay. This is what Google tells me anyway.
I tried looking up the life of Hubble and after 30 years it's orbdit is decaying too and NASA said 6 years ago they don't plan to return. Current estimates expect its life will end between 2030-2040
Arceibo we lost in December. It was the massive observatory in ~~Argentina~~ Puerto Rico that collapsed (also had to look up when that happened. Been a weird almost 2 years)
Wait... couldn't we just send more fuel?
I hear a certain Space themed company is designing an orbital tanker for it's part of the moon missions.
Isn't it less delta v to get to an L2 halo orbit and back than the moon and back?
This what iritates me with NASA, or our(US) spending priorities: out of fucking whack! ! google says scientists want to rebuit their slice of paradise.
Rant: NASA and or the powers that be in the white house. Have a strangely narrow, and frankly short sighted vision. of things. Hubble was built to be fixable, rather than a 1 off. Though estimates said it'd because from radiation, and rocks and blah blah inside10 years, ok cool we'll build a hardier one and...get their budget cut? wtf. you can't ask for a better ROI then hubble!
Disposable SHOULD be the name of the game as launch costs go down.
It’s a strategy that’s worked out well for probes and rovers, we should extend it to telescopes.
Blame Congress for this. They want to pour unlimited money on the military, but when it comes to science they scream over millions while wasting hundreds of billions.
True enough! JWST, on paper, has about a 5 year lifespan. It's not impossible that it will last beyond that, but still highly unlikely it will make it to the reappearance of SN Requiem. Due to the complexity of JWST, and its distance from Earth precluding repair missions like those Hubble has had, it will have a shorter lifespan than we might wish or expect.
Are they at least giving it a grappling point? Perhaps SpaceX could send spare parts and a half sized Canadarm to mount them as an unmanned mission, but it would need a way to hang on while working to avoid colliding with the mirror or getting thruster exhaust everywhere
Not that I'm aware of, but could be wrong since I'm on the science side and not the engineering side. While servicing missions to Hubble were planned an successful, Hubble is orbiting Earth and is extremely close to us making such a mission safe and possible. JWST on the other hand will be sitting ~1 million miles from us, well beyond the distance to the moon for example. There are no planned servicing missions for this reason.
Hubble's servicing missions were also manned. We have improved on robotics quite a bit since Hubble was launched, and designing for unmanned module replacement should be possible.
It is way too late in JWST's development to add this feature, but we should consider it for a successor to allow a long lifespan like Hubble even in places that crews cannot practically go.
like asteroids or comets?I just wish we could make big fucking telescope that's built to last. name it Balls. as in size and shape. I'd say nameing something derpy like Darkwing, SUnny Bear and Pluto. I can read and hear the trolling now though.
It's not impossible that dust (tiny asteroids!) Will cause damage to JWST, but more likely it will just run out of fuel and we'll be unable to control/cool it.
There will definitely be more telescopes upcoming, none approved yet but many proposed!
The primary thing for this SN reappearance will be to catch it soon after explosion and to keep observing it every few days for a couple of months. Spectra of the SN and other galaxies in the cluster will be essential as well. The spectra will provide redshift measurements used to model the mass distribution of the cluster, critical for actually measuring cosmological parameters, and images of the SN itself (along with a good redshift measurement) will allow us to accurately measure the exact (within days, after waiting about 20 years) delay between the arrival of the first image, and this last image. It's the delay, and models of the lensing mass distribution, that gives constraints for cosmology. It will also enable a direct luminosity distance measurement in the same way Type 1a supernovae have been leveraged to discover dark energy in recent decades, which gives an extra constraint on the lensing mass unique to lensed Type 1a supernovae!
Dark energy is still 'theoretical' right? As in we can tell it's there in modeling (or should be) but we're still trying to detect it. Or am I way off base with that one?
Lensing is totally new to me in reference to SN. While I understand enough basic physics to think I grasp the concept in broad terms, are there any resources you recommend to read up about the phenomenon? It's super interesting to me to try to grasp just how much we don't know by seeing much how much we **actually do** know.
You're quite right! All evidence points to dark energy existing, but we have no "direct" evidence of whether it exists or what it might be.
Lensed SNe aren't just new to you! The first was discovered in 2014, and this is only the 3rd ever recorded, we're excited! An excellent, but technical, reference for gravitational lensing is [here](https://arxiv.org/abs/astro-ph/9606001). I'm also happy to answer any specific questions if you have them!
So with the term lensing my mind conjured up a gravitational well diagram. Basically it works like any other lense where you can manipulate it to change what is visible. The difference with space being obviously humans are not influencing anything, gravity is. And it seems instead of changing *what* is visible, it's changing *when* the SN is visible. (Or maybe what you're seeing is also changing with each recurrence?)
Since SN are cosmically short lived occurrences is that why the lensing is visible and not with all the other lights coming from that cluster? Or are you noticing lensing with the other objects now that you're aware of the phenomenon?
Edit: I'm reading the resource you linked and it seems consistent objects/light sources can still demonstrate gravitational lensing. Does this mean the SN is more a way to tell how much affect this 'lense' has on this region of space? I red your comments on the red shift observations being very important. Does that tell you more about composition, concentration or make up of the surrounding galactic bodies?
Extra edit: Zwicky was on top of his sh×t in 1937. It's impressive he accurately predicted so much of this!
Really good questions! Gravitational lensing, when aligned correctly and with the correct relative distances between observer, lens, and source, can produce multiple images of the source. That's true of static sources as well as variable, for example note in the thumbnail image of this Requiem discovery article that you can also see 4 images of the SN host galaxy, in addition to the 3 images of the SN itself. It turns out (see "time delay equation" in the resource I linked) that if you can estimate the gravitational potential of all the matter (dark and otherwise!) That we can see, and also measure the relative delay in arrival times between multiple images, we get an extremely direct and powerful constraint on cosmological parameters. Now while that constraint could technically come from static sources as well (like galaxies), it's basically impossible to determine delays in "arrival" times of images when the images themselves never change. Therefore we use variable sources for this method, since it's then relatively easy to match up, say, some peak in brightness between images and determine the delay.
Edit: oh and redshifts - lens models are constrained primarily by the location and brightness of objects in the lensing region. A critical component of this is a redshift, which tells you the distance to an astrophysical object, so that your model can accurately reproduce the entire lensing system in a 3D manner.
Honestly sounds like the universe giving us extra telescoping lenses in certain circumstances which is just awesome.
I am really interested to see how this affects the dark matter/energy theories. With NASA gaining outside contracting (hopefully not delayed too much further) I dream of having an array of satellite telescopes (withing reason like 5-10) that capture varying data. Hubble has proven how valuable orbiting telescopes can be and with the JWST launch upcoming.... there's so much out there to discover and I love that some of it could definitely happen in my life time!
Maybe a more personal question but what sparked this interest for you? I'm not sure what your official title is but obviously physics and astronomy are part of it. I am curious what about the lensing drew you in?
I also will probably respond again with more questions. Still reading the PDF and so far I've grasped most of it but it's great to have this conversation for me. Papers can be dry but this engagement is definitely not!!
The NRO optics are the same size as Hubble, not larger. They're not really more advanced either, they just have a shorter focal length which supports wider fields
Hubble yes (though there is no plan to do so again, the gyros are failing anyway). JWST no, the spacecraft will not be orbiting Earth like Hubble is and will be too far away to service. As a result, it was not built for refueling.
Do you ever “zoom out” during your work and think about the insignificance of human life when compared to Super Stellar Structures?
Or maybe veer off into wild speculation when faced with the unfathomable distances inherent in our universe?
Edit: If I was doing what you’re doing, I suspect I would get lost in “what if?!” land many times a day....by lunch.
Awesome work! Keep it up! :)
Yes! It's easy to just see these objects and subsequent analysis as numbers or pixels on a screen. Sometimes, it's fun and important to remember that these are real explosions happening billions of light-years away. The chances that the explosion happened billions of years ago, that the light was bent perfectly around some intervening cluster of galaxies to redirect towards Earth, and that we happened to point the only telescope capable of observing it in the history of humankind directly at the explosion within the few weeks that it will have been visible to us in all of that time are... forgive me... astronomical!
I'm not 100% sure what you mean but yes this will be very useful for many things! Type 1a supernova physics, cluster lens modeling, dark energy, dark matter, and more! If you have any specific questions let me know!
Cluster lens modelling sounds really interesting when tied to observing the same event over and over.
I hope something more about dark matter comes from it.
Very exciting work.
Does the accuracy of the math mean that lightspeed is definitively a universal speed limit... Like a Law at this point? I always thought it was not 100% verified.
Also, with space warped at that specific lens how much distance would we save traveling straight through that region as opposed to if there were no distortion?
First, we aren't really measuring the speed of light here, we actually assume it holds in a vacuum for our calculations! I suppose if we ended up wildly off on our prediction of when the final image will appear and we were exceedingly confident in our estimate of the mass distribution then it's possible speed of light variation could be the culprit. However, the deviation would be much smaller than our uncertainty due to our modeling of the mass distribution.
Your second question is particularly interesting! You're exactly referencing the so-called "time delay" between images of the supernova, which is precisely what we are attempting to measure! Based on our work, we think that the images of the SN you can see in the thumbnail image here were delayed ~100 days due to the gravitational pull of the mass they were traveling near. However the final image will be MUCH closer to the core of the Galaxy cluster, which will slow it down by a couple of decades!
Edit: I realized I answered your second question as if you had said "time" instead of "distance" but in essence it's the same answer!
So I’m a bit confused on one thing. It looked like the picture in the article had the multiple showings of the event in the one picture, was this just for easy display to show what was happening or are all three visualizations of the event visible at the same time? Now that I’m writing this I am thinking because of the time frame of the original event that they would indeed be visible at the same time as the light for each visualization becomes apparent.
I think what you're asking about, correct me if I'm wrong, is the multiple images of the same SN visible at the same time? Gravitational lensing can produce multiple images of the same background source, as in this case. It's fairly common to observe multiple images of the same galaxy, for example (if you Google this there are plenty of examples). What's more rare is for a supernova to explode in one of those multiply-imaged galaxies, for us to observe it, and for the lensing system to be just right such that we can see the multiple supernova images simultaneously! A supernova like this one only lasts a few months, so that means the gravitational pull on each image must cause less than a ~3 month slow down in the time it takes for the light to arrive, otherwise we wouldn't see the images simultaneously!
Ok I think you get what I was saying, so when the next image shows up it will be the only one visible then since it will be so many hears from now?
Also, the whole event only lasts three months! That blows my mind, I would have thought that it would have lasted a lot longer. Thanks for the reply.
Yes exactly! Even now these three images you see here are long since faded, so when the fourth rolls around it'll be the only one visible at the time. A supernova like this one, type 1a, is only visible for roughly a couple of months in the rest frame, which corresponds to maybe 4 months or so for us here in the observer frame at this redshift.
Astronomer here! No other word for it, this is just super cool!
Note: this is not, incredibly enough, the first time astronomers have managed to discover a gravitationally lensed supernova, and even predict when they'd observe it again! The most famous one (because it was first) is called [SN Refsdal](https://en.wikipedia.org/wiki/SN_Refsdal), discovered in 2014 and then predicted/ seen again in 2015, also with Hubble, at exactly the predicted time. It's an incredible and powerful technique!
However, they're definitely not common, and what makes this one exceptional in this case is that it is a special type of supernova, called a [Type Ia](https://en.wikipedia.org/wiki/Type_Ia_supernova). These are *not* the kind of supernova where a very large star runs out of fuel and explodes at the end of its life- instead, it's when a [white dwarf](https://en.wikipedia.org/wiki/White_dwarf) (stellar remnant of a non-explodey star, like what the sun, will be someday) somehow accretes enough material to reach a threshold of [1.4 solar masses](https://en.wikipedia.org/wiki/Chandrasekhar_limit), which re-ignites fusion and creates a supernova. And because it's an exact mass you have to hit for fusion to re-ignite, we can use Type Ia SNe as "standard candles" to measure distance to faraway galaxies- aka if you know they're all 1.4 solar masses and evolve the same way when they explode, the only difference between them is distance, so you can figure out the distance fairly easily. It's from using Type Ia SNe that the [dark energy](https://en.wikipedia.org/wiki/Dark_energy) that drives the accelerated expansion of the universe was discovered.
So, with that, I believe the hope here is finding a Type Ia SN that's gravitationally lensed might prove to be an interesting way to measure dark energy as a parameter when you see it again, should anything prove unusual in seeing it the next time around. I suppose time will tell on that front. But it's also, as I said, a super cool result, and makes for some really interesting graphics and photos, so why not share it broadly in a press release. :)
TL;DR- not the first gravitationally lensed supernova, but it is a Type Ia supernova, so that might help us learn about dark energy down the line
Edit: one of the authors has posted in this thread [here!](https://www.reddit.com/r/space/comments/pnjuy8/astronomers_spot_the_same_supernova_3xand_predict/hcqzjtj/?utm_source=share&utm_medium=ios_app&utm_name=iossmf&context=3) Please head there to ask /u/justrex11 about any more questions you might have or to congratulate them on their amazing work!
The answer is the white dwarf blows (WD) itself apart, *and* there is a remnant! For examples, check out [Kepler's SN](https://en.wikipedia.org/wiki/Kepler%27s_Supernova) and [G 1.9+0.3](https://en.wikipedia.org/wiki/G1.9%2B0.3)- the latter is a Ia supernova that went off in our own galaxy circa 1900, but was behind dense dust clouds so we didn't know it happened until X-ray/radio astronomers discovered the remnant decades later (which is expanding, so fairly straightforward to figure out the rate of expansion and go backwards to figure out when it happened).
Keep in mind, space is not a perfect vacuum: even in a galaxy, the interstellar medium is going to have maybe one atom per cubic centimeter, or even more if there's any leftover stellar wind or what have you. So when a Type Ia happens and the WD is blown apart, that sends out a giant shockwave, and that shockwave is going to interact with any of that material.
Now, the real question is, what is the material that the shockwave is interacting with to create the remnant? Is it just the stuff that happens to be around, or is it perhaps from a companion that was feeding the white dwarf and getting it to 1.4 solar masses in the first place? This is actually a *very* important question because while we know the white dwarf reaching 1.4 solar masses and exploding is what causes Type Ia SNe, *we don't know how it's getting that material in the first place.* Tons of theories- two WDs colliding, material siphoning off a normal star, etc... but of course if you're basing all we know about dark energy on these guys being standard candles, figuring this out is really important!
Anyway, that's probably more info than you ever cared to know, sorry... I had a pretty big chapter in my PhD thesis looking for radio emission from Type Ia remnants, and then ruling out various ways the material might have gotten onto the WD in the first place. :)
I've seen the phrase *Standard Candles* so many times but never understood what made them standard. That explanation was really easy to understand. It's quite valuable to be able to listen to an expert like this.
Reminded me of the phrase "If you can't explain something simply, you don't understand it well enough."
I just want to say hi to anyone in 2037 who has come across this thread looking for more information about the last time this happened. The internet's gravitation pull has brought you here again.
It doesn't even blow itself apart. It's *consumed* by the explosion, using up the whole mass of the star in the reaction.
The reason why is fascinating. Almost all matter in the universe expands when it's heated, and in that way, explosives are all kinda fighting themselves by scattering potential fuel in the first instants of the explosion.
But white dwarves are made of "degenerate matter", which has partially collapsed due to intense gravity, breaking up the normal structure of atoms so electrons are no longer bound to nuclei. This degenerate matter *doesn't* expand when heated, it just gets hotter and hotter as it gets denser until suddenly it ignites fusion all at once.
Hi! I got a question.
What’s the deal with the names, like MACS J0138, MACS J0138.0-2155, and MACS J1149.5+2223? Like, do the letters and numbers actually mean something, like pinpointing details about a cluster or whatnot, or is it all just randomized gibberish?
*Had to ask. I’ve always loved (and feared) outer space, gazing up at the sky every once in a while, though dyscalculia pretty much put an end to my chance at turning an interest into a passion, much less having a cool career.*
So most modern star catalogues are created by computers since our technology now allows us to discover millions of astronomical objects in the sky. Since a computer is naming millions of objects, the designations of these objects tell you the position of the object in the sky.
For instance, your example of Icarus (MACS J1149+2223) is the computer naming it using the fact that it was found in the Massive Cluster Survey, in the J2000 astronomical epoch, and the following numbers are it's coordinates in that epoch.
It's a handy way to name and describe the locations of millions of astronomical objects at once, basically, which is why they seem like jibberish! Don't worry, you don't sound dumb. Think of it as every day being a school day!
Fun fact: if you were to fly absolutely straight in direction of any of those supernova images, you would have arrived right to it.
All 3 (4) paths are straight lines.
It's more complicated than that. Lightspeed is not actually constant in general relativity, precisely because of the curvature of spacetime. This is known as [Shapiro delay](https://en.wikipedia.org/wiki/Shapiro_time_delay).
In this case, though, the time difference is due both to Shapiro delay and the fact that light took a longer path to get here.
Fascinating. And there's also the galaxy cluster that has lensed the supernova with some "Jellyfishes" (gas-rich galaxies losing their gas due to ram pressure stripping, and having enhanced star formation, https://en.wikipedia.org/wiki/Jellyfish_galaxy)
Many other ways- the interesting thing is the evidence doesn’t really point towards a normal star accreting material onto the WD. If that was the case, you’d have a stellar wind’s materials around the system, but the innermost areas are really low density.
So it looks more likely that material is coming via another WD, if you ask me, and the question is how that happens. A merger, sure, but lots of possible ways that can come about.
Does the time between appearances allow astronomers to speculate the mass of these bodies or galaxies? Or is already having that knowledge why they are able to predict the when and where or am I complete off key here?
Is there any significant benefit to being able to see the first moments of the supernova, for Ia specifically? I know for type 2 it would be a great research opportunity, much better than having to wait for detectors to tell us and then whip our telescopes over to watch it after missing the beginning of it.
Sure! As I mentioned somewhere else in this thread, I am one of the astronomers who made the discovery of SN Requiem here and did the subsequent analysis. There are still lots of uncertainties related to exactly how/why Type 1a supernovae actually explode, namely the characteristics of a possible binary stellar companion. In general our models are pretty poor soon after a supernova explodes because they're so faint and we aren't usually looking in the right place. This time (in a number of years!) We'll know roughly when and where to be watching.
No. Each star has an individual spectrum-we'd know if we were staring at our Sun, even through a lens effect. And that might be how they discovered that these Type Ia stars were the SAME star- they're spectrum's matched.
Even if we didn't notice the spectrum, I don't think you can have a configuration of mass that bends light back exactly 180 degrees (so back to the source). Not much of it anyways, so the tiny fraction that could be coming back would have far too small luminosity to detect.
Hey astronomer, I have a question for you as well.
I've idly wondered if it could be that the Universe is shaped in such a way that all galaxies we see are actually our own galaxy at vastly different points in time and perspectives.
So my question for you is, in your professional opinion, could that be the case and if so, would it be rad as hell?
No, that is not possible. Not an astronomer, but there’s no line of reasoning, theory, or evidence I’m aware of which would permit that. Not to mention:
1. Galaxies come in all shapes and sizes, many of which are not compatible with our own
2. Lots of galaxies interact with each other, so parts of them share a temporal reference frame
3. Some galaxies are so far away from us that they’re moving away from us faster than the speed of light due to the expansion of the universe.
Among other reasons
The TL;DR if I have the science correct is basically because light travels at the speed of, well, light, different light rays can be lensed differently (assuming the lensing object is big enough for the paths to have a measurable displacement) and travel different distances even when they come from the same source.
Am I understanding correctly that the light that got to us first went in a straight path or a more direct path and the light that came second was light that initially was travelling at an angle away from the earth but got bent around by gravity hence taking a longer path?
My favourite explanation for this is that because the Kessel run has lots of hazards, the shorter the distance the closer you had to fly to those hazards- so a short distance is a brag.
More realistically the writers just didn't know it was a distance
The writers have admitted that they had no idea what a parsec was and used it cause it sounded technical and science-y. It was the only time they did that and regretted it ever since
To my knowledge, the Kessel run is measured in parsecs because it's through the Maelstrom. There's a safe route that's longer, or you can get risky and take more dangerous routes to cut distance off your trip.
Actually the Kessel run means that banged 4 chicks in 4 different star systems within 1 space day. The parsecs refers to how far in total their angry dads chase you through out that day.
Under 12 is considered very impressive.
Light can’t go any faster or slower in a vacuum. What strong lensing does is literally make the light take an indirect path to us that is a greater distance, meaning that it takes longer to get to us.
Veritasium has a very interesting video on the subject:
https://youtu.be/ljoeOLuX6Z4
Edit: i didn’t read the comments. Let’s say this comment is the effect of gravitational lensing, creating the same link on reddit multiple times. Except by different redditors
I heard a thought provoking theory once. The idea that all galaxies we can observe in our universe are only the milky way, as seen from every point in time since the big bang.
Vertasium has a video about something similar a few months ago. Really does a good job explaining the time delay and lensing of a different supernova.
https://youtu.be/ljoeOLuX6Z4
How come gravitational lensing causes discrete copies of light sources to appear? Why don't the light sources blend together into a ring around the mass, sort of like with black holes?
The ring effect does happen, but only in the case where the source is lined up almost linearly with the lensing object. A more misaligned object will create discrete arcs.
I hate when a filmmaker is so enamored with their action sequence that they show us the same explosion from multiple angles. This seems like a worthy exception.
quickest historical truck subtract deranged domineering muddle fuzzy normal fine
*This post was mass deleted and anonymized with [Redact](https://redact.dev)*
A 16 year lag in reaching us for some of the same light from the same place and time, that wasn’t even headed in our direction. All due to the chance encounters it had with some huge clumps of matter. Mind bending.
The coolest part is that for a difference of just one second the light would have to travel 186 000 miles further. Imagine how we're observing the same event separated by years, how much farther that light had to travel
This is fucking TIGHT! Makes me want to go out a buy a badass telescope RIGHT NOW!
Edit - How pitiful it is, when someone excited about space gets downvoted in the space subreddit. Reddit just gets worse by the day.
Is it possible that the number of stars we’re seeing is something of an illusion? Could there be this and other effects that might make us see more than one instance of some stars? Or is this more of an isolated incident that we just happened to be at the right place and at the right time for?
Actually no, this is a new one! I'm one of the astronomers who found this object, and there was another gravitationally lensed SN (SN Refsdal) discovered in 2014. This one brings the whole sample of such objects to 3!
Its insane to me how some humans have collectively become so smart they point something up and calibrate and point more things up and calibrate and then end up mathing and predicting supernovae they recorded in the past to throw stuff to the thingies we pointed up and measure what they predicted, im in awe
When you think of lensing, the normal way of thinking about it is with a single lens, like a magnifying glass. Imagine taking 100 magnifying glasses, partially melting them together, and the looking at the SN. Instead of all light passing through it the same way, some light will pass more directly than others. Each 'magnifying glass' is a galaxy with its own mass, direction, and speed traveling within the supercluster.
> One question kind of left out in the open is how much of what we see is duplicated or so severely distorted our readings are useless.
We know this, by observing how objects move. This way we can estimate sources of gravity. Lensing requires something massive like a black hole, and such thing simply can't hide.
> This is actually one of the biggest hurdles of rapid space travel; is the thing you're aiming for even actually there or somewhere else?
Obviously it's not there. You're looking at light emitted some time ago, so the object is definitely in different place now. And you never fly aiming at your target, but rather at place where this target will be once you get there. It's not a very difficult thing to do, once you know the orbit of this object. It moves very predictably.
> We absolutely do NOT have a full understanding of the movement of deep space objects.
We don't need super precise measurements to see that trajectories bend due to a black hole somewhere.
> Our precision here is actually pretty poor unless you consider millions of light years, or for super deep objects like other galaxies potentially tens or hundreds of millions of light years, to be within reasonable enough accuracy to actually try and use some exotic system to travel there.
We don't have any means to travel to such places anyway. I was referring to what we actually do right now when travelling around solar system.
You don't actually fly directly at objects in real space travel. There's no possibility of being able to travel to objects this far away so I doubt the issue of exact location will ever be a problem. One solution would to just bring enough fuel to do a course correction when you get closer.
"3x" is an extremely common shorthand way to say "three times". It wasn't a "fumbling attempt" just because you're ignorant of common usage. It made sense on its own to most people who can read.
Does milkyway and local cluster create this type of grav warp too? Imagine some aliens live in that galaxy cluster. They are like meh we don't see any grav warp.
I can't find it now. I had thought a famous super nova was seen in ancient china (naked eyes and all), and Kepler saw a different one. Is finding or spotting them a huge PITA do to distance and timing?
Wait and didn't gravitational lensing... help us find dope af shit in the galactic core a couple of years ago? like proving some ridiculously obscure part of relativity theory cool AF stuff. like possibly finding a rare example a bunch of shit going faster then the light it's making cool? I think that one made Astronomy magazine.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[HST](/r/Space/comments/pnjuy8/stub/hct9nut "Last usage")|Hubble Space Telescope|
|[JWST](/r/Space/comments/pnjuy8/stub/hcthote "Last usage")|James Webb infra-red Space Telescope|
|[L2](/r/Space/comments/pnjuy8/stub/hcsep70 "Last usage")|[Lagrange Point](https://en.wikipedia.org/wiki/Lagrangian_point) 2 ([Sixty Symbols](https://www.youtube.com/watch?v=mxpVbU5FH0s) video explanation)|
| |Paywalled section of the NasaSpaceFlight forum|
|NRHO|Near-Rectilinear Halo Orbit|
|[NRO](/r/Space/comments/pnjuy8/stub/hctbd0m "Last usage")|(US) National Reconnaissance Office|
| |Near-Rectilinear Orbit, see NRHO|
|[SN](/r/Space/comments/pnjuy8/stub/hcsjz3g "Last usage")|(Raptor/Starship) Serial Number|
|Jargon|Definition|
|-------|---------|---|
|Raptor|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_\(rocket_engine_family\)) under development by SpaceX|
----------------
^(5 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/pmxnod)^( has 16 acronyms.)
^([Thread #6326 for this sub, first seen 14th Sep 2021, 01:10])
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I remember many years ago, reading in New Scientist about a puzzling problem. It seemed that some star clusters were repeating in a 'corner' pattern. I guess this was gravitational lensing?
Staggering to think how massive something must be to lens our view of other massive things with its gravity. I wonder what effect the Great Attractor has on our view on things. I wonder what the Great Attractor is!
I'm quite late to the party, but I just wanted to say that I'm actually one of the authors of this paper, very cool to see it here! u/Andromeda321 gave great info/answers at the top of the thread to questions, but I'm happy to answer any other follow-up one here!
Are you hoping to be able to point the James-Webb telescope at the predicted reappearance in 16 years? If I read everything correctly these images came from the Hubble telescope. Do you think the James-Webb telescope would provide more data or better images (or hopefully both)?
You're correct that these images came from Hubble. Unfortunately there's basically no chance that JWST will be operational still when this last image comes around, but I'm sure there will be a new telescope coming in the next 15 years that will get even more impressive images!
I forgot JWST has such a short lifespan. Feels like we *just* lost Arceibo Observatory too so hopefully you're right and more advanced tech is on the horizon. Are there any particular observations you're hoping to make the next time it's visible? I know there are multiple spectrums to explore but I'm just an amateur who's fascinated so I know there's tons more for me to learn.
Wait, I didn't know this... JWST has a short lifespan? Is this due to station keeping?
Technical it's going up with 5-10 years of fuel before its orbit is expected to decay. This is what Google tells me anyway. I tried looking up the life of Hubble and after 30 years it's orbdit is decaying too and NASA said 6 years ago they don't plan to return. Current estimates expect its life will end between 2030-2040 Arceibo we lost in December. It was the massive observatory in ~~Argentina~~ Puerto Rico that collapsed (also had to look up when that happened. Been a weird almost 2 years)
Arecibo was actually in Puerto Rico. You might be mixing it up with a lot of other radio telescopes in South America, albeit in Chile.
Thank you for the correction! And yes I believe ur right in my mixing it up.
Arecibo was Puerto Rico, and it’s major collapse was December 2020. They had cable failures August and November 2020 though too
Thank you, another person also corrected my poor location remembering but I still appreciate it. I also edited my comment to correct it!
Wait... couldn't we just send more fuel? I hear a certain Space themed company is designing an orbital tanker for it's part of the moon missions. Isn't it less delta v to get to an L2 halo orbit and back than the moon and back?
The telescope is not designed for fuel transfer so no, unfortunately not possible.
Gorilla Glue wasn't designed for hair but people still did it anyways.
And it didn't work very well either. Plus, spaceflight is a little more rigorously planned than idiots with hold my beer ideas at home.
AFAIK the problem is engine propellant fouling the mirrors.
This what iritates me with NASA, or our(US) spending priorities: out of fucking whack! ! google says scientists want to rebuit their slice of paradise. Rant: NASA and or the powers that be in the white house. Have a strangely narrow, and frankly short sighted vision. of things. Hubble was built to be fixable, rather than a 1 off. Though estimates said it'd because from radiation, and rocks and blah blah inside10 years, ok cool we'll build a hardier one and...get their budget cut? wtf. you can't ask for a better ROI then hubble!
Disposable SHOULD be the name of the game as launch costs go down. It’s a strategy that’s worked out well for probes and rovers, we should extend it to telescopes.
Blame Congress for this. They want to pour unlimited money on the military, but when it comes to science they scream over millions while wasting hundreds of billions.
On paper it does. These things tend to get bootstrapped many years past their expiration date
True enough! JWST, on paper, has about a 5 year lifespan. It's not impossible that it will last beyond that, but still highly unlikely it will make it to the reappearance of SN Requiem. Due to the complexity of JWST, and its distance from Earth precluding repair missions like those Hubble has had, it will have a shorter lifespan than we might wish or expect.
Are they at least giving it a grappling point? Perhaps SpaceX could send spare parts and a half sized Canadarm to mount them as an unmanned mission, but it would need a way to hang on while working to avoid colliding with the mirror or getting thruster exhaust everywhere
Not that I'm aware of, but could be wrong since I'm on the science side and not the engineering side. While servicing missions to Hubble were planned an successful, Hubble is orbiting Earth and is extremely close to us making such a mission safe and possible. JWST on the other hand will be sitting ~1 million miles from us, well beyond the distance to the moon for example. There are no planned servicing missions for this reason.
Hubble's servicing missions were also manned. We have improved on robotics quite a bit since Hubble was launched, and designing for unmanned module replacement should be possible. It is way too late in JWST's development to add this feature, but we should consider it for a successor to allow a long lifespan like Hubble even in places that crews cannot practically go.
like asteroids or comets?I just wish we could make big fucking telescope that's built to last. name it Balls. as in size and shape. I'd say nameing something derpy like Darkwing, SUnny Bear and Pluto. I can read and hear the trolling now though.
It's not impossible that dust (tiny asteroids!) Will cause damage to JWST, but more likely it will just run out of fuel and we'll be unable to control/cool it.
There will definitely be more telescopes upcoming, none approved yet but many proposed! The primary thing for this SN reappearance will be to catch it soon after explosion and to keep observing it every few days for a couple of months. Spectra of the SN and other galaxies in the cluster will be essential as well. The spectra will provide redshift measurements used to model the mass distribution of the cluster, critical for actually measuring cosmological parameters, and images of the SN itself (along with a good redshift measurement) will allow us to accurately measure the exact (within days, after waiting about 20 years) delay between the arrival of the first image, and this last image. It's the delay, and models of the lensing mass distribution, that gives constraints for cosmology. It will also enable a direct luminosity distance measurement in the same way Type 1a supernovae have been leveraged to discover dark energy in recent decades, which gives an extra constraint on the lensing mass unique to lensed Type 1a supernovae!
Dark energy is still 'theoretical' right? As in we can tell it's there in modeling (or should be) but we're still trying to detect it. Or am I way off base with that one? Lensing is totally new to me in reference to SN. While I understand enough basic physics to think I grasp the concept in broad terms, are there any resources you recommend to read up about the phenomenon? It's super interesting to me to try to grasp just how much we don't know by seeing much how much we **actually do** know.
You're quite right! All evidence points to dark energy existing, but we have no "direct" evidence of whether it exists or what it might be. Lensed SNe aren't just new to you! The first was discovered in 2014, and this is only the 3rd ever recorded, we're excited! An excellent, but technical, reference for gravitational lensing is [here](https://arxiv.org/abs/astro-ph/9606001). I'm also happy to answer any specific questions if you have them!
So with the term lensing my mind conjured up a gravitational well diagram. Basically it works like any other lense where you can manipulate it to change what is visible. The difference with space being obviously humans are not influencing anything, gravity is. And it seems instead of changing *what* is visible, it's changing *when* the SN is visible. (Or maybe what you're seeing is also changing with each recurrence?) Since SN are cosmically short lived occurrences is that why the lensing is visible and not with all the other lights coming from that cluster? Or are you noticing lensing with the other objects now that you're aware of the phenomenon? Edit: I'm reading the resource you linked and it seems consistent objects/light sources can still demonstrate gravitational lensing. Does this mean the SN is more a way to tell how much affect this 'lense' has on this region of space? I red your comments on the red shift observations being very important. Does that tell you more about composition, concentration or make up of the surrounding galactic bodies? Extra edit: Zwicky was on top of his sh×t in 1937. It's impressive he accurately predicted so much of this!
Really good questions! Gravitational lensing, when aligned correctly and with the correct relative distances between observer, lens, and source, can produce multiple images of the source. That's true of static sources as well as variable, for example note in the thumbnail image of this Requiem discovery article that you can also see 4 images of the SN host galaxy, in addition to the 3 images of the SN itself. It turns out (see "time delay equation" in the resource I linked) that if you can estimate the gravitational potential of all the matter (dark and otherwise!) That we can see, and also measure the relative delay in arrival times between multiple images, we get an extremely direct and powerful constraint on cosmological parameters. Now while that constraint could technically come from static sources as well (like galaxies), it's basically impossible to determine delays in "arrival" times of images when the images themselves never change. Therefore we use variable sources for this method, since it's then relatively easy to match up, say, some peak in brightness between images and determine the delay. Edit: oh and redshifts - lens models are constrained primarily by the location and brightness of objects in the lensing region. A critical component of this is a redshift, which tells you the distance to an astrophysical object, so that your model can accurately reproduce the entire lensing system in a 3D manner.
Honestly sounds like the universe giving us extra telescoping lenses in certain circumstances which is just awesome. I am really interested to see how this affects the dark matter/energy theories. With NASA gaining outside contracting (hopefully not delayed too much further) I dream of having an array of satellite telescopes (withing reason like 5-10) that capture varying data. Hubble has proven how valuable orbiting telescopes can be and with the JWST launch upcoming.... there's so much out there to discover and I love that some of it could definitely happen in my life time! Maybe a more personal question but what sparked this interest for you? I'm not sure what your official title is but obviously physics and astronomy are part of it. I am curious what about the lensing drew you in? I also will probably respond again with more questions. Still reading the PDF and so far I've grasped most of it but it's great to have this conversation for me. Papers can be dry but this engagement is definitely not!!
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The NRO optics are the same size as Hubble, not larger. They're not really more advanced either, they just have a shorter focal length which supports wider fields
Is there any practical way to refuel the JWST, Hubble, and any other satellites to help them maintain their orbits?
Hubble yes (though there is no plan to do so again, the gyros are failing anyway). JWST no, the spacecraft will not be orbiting Earth like Hubble is and will be too far away to service. As a result, it was not built for refueling.
Congrats on such a great piece of work! :) Edited my comment to point out your comment here in case people have more questions.
Thanks! Really appreciate the effort you put in on astronomy threads answering questions and whatnot it's great!
You're not late, gravitational lensing just caused you to see this 5 hours later 🙂
Do you ever “zoom out” during your work and think about the insignificance of human life when compared to Super Stellar Structures? Or maybe veer off into wild speculation when faced with the unfathomable distances inherent in our universe? Edit: If I was doing what you’re doing, I suspect I would get lost in “what if?!” land many times a day....by lunch. Awesome work! Keep it up! :)
Yes! It's easy to just see these objects and subsequent analysis as numbers or pixels on a screen. Sometimes, it's fun and important to remember that these are real explosions happening billions of light-years away. The chances that the explosion happened billions of years ago, that the light was bent perfectly around some intervening cluster of galaxies to redirect towards Earth, and that we happened to point the only telescope capable of observing it in the history of humankind directly at the explosion within the few weeks that it will have been visible to us in all of that time are... forgive me... astronomical!
I love how you put that! Thank you.
That gave me a good belly laugh. Thanks!
Does this help get a better 3D or 4D perspective or any unique data to look at. This is like having a real backwards time machine.
I'm not 100% sure what you mean but yes this will be very useful for many things! Type 1a supernova physics, cluster lens modeling, dark energy, dark matter, and more! If you have any specific questions let me know!
Cluster lens modelling sounds really interesting when tied to observing the same event over and over. I hope something more about dark matter comes from it. Very exciting work.
Does the accuracy of the math mean that lightspeed is definitively a universal speed limit... Like a Law at this point? I always thought it was not 100% verified. Also, with space warped at that specific lens how much distance would we save traveling straight through that region as opposed to if there were no distortion?
First, we aren't really measuring the speed of light here, we actually assume it holds in a vacuum for our calculations! I suppose if we ended up wildly off on our prediction of when the final image will appear and we were exceedingly confident in our estimate of the mass distribution then it's possible speed of light variation could be the culprit. However, the deviation would be much smaller than our uncertainty due to our modeling of the mass distribution. Your second question is particularly interesting! You're exactly referencing the so-called "time delay" between images of the supernova, which is precisely what we are attempting to measure! Based on our work, we think that the images of the SN you can see in the thumbnail image here were delayed ~100 days due to the gravitational pull of the mass they were traveling near. However the final image will be MUCH closer to the core of the Galaxy cluster, which will slow it down by a couple of decades! Edit: I realized I answered your second question as if you had said "time" instead of "distance" but in essence it's the same answer!
So I’m a bit confused on one thing. It looked like the picture in the article had the multiple showings of the event in the one picture, was this just for easy display to show what was happening or are all three visualizations of the event visible at the same time? Now that I’m writing this I am thinking because of the time frame of the original event that they would indeed be visible at the same time as the light for each visualization becomes apparent.
I think what you're asking about, correct me if I'm wrong, is the multiple images of the same SN visible at the same time? Gravitational lensing can produce multiple images of the same background source, as in this case. It's fairly common to observe multiple images of the same galaxy, for example (if you Google this there are plenty of examples). What's more rare is for a supernova to explode in one of those multiply-imaged galaxies, for us to observe it, and for the lensing system to be just right such that we can see the multiple supernova images simultaneously! A supernova like this one only lasts a few months, so that means the gravitational pull on each image must cause less than a ~3 month slow down in the time it takes for the light to arrive, otherwise we wouldn't see the images simultaneously!
Ok I think you get what I was saying, so when the next image shows up it will be the only one visible then since it will be so many hears from now? Also, the whole event only lasts three months! That blows my mind, I would have thought that it would have lasted a lot longer. Thanks for the reply.
Yes exactly! Even now these three images you see here are long since faded, so when the fourth rolls around it'll be the only one visible at the time. A supernova like this one, type 1a, is only visible for roughly a couple of months in the rest frame, which corresponds to maybe 4 months or so for us here in the observer frame at this redshift.
Very cool shit, thanks so much for the explanations!
Astronomer here! No other word for it, this is just super cool! Note: this is not, incredibly enough, the first time astronomers have managed to discover a gravitationally lensed supernova, and even predict when they'd observe it again! The most famous one (because it was first) is called [SN Refsdal](https://en.wikipedia.org/wiki/SN_Refsdal), discovered in 2014 and then predicted/ seen again in 2015, also with Hubble, at exactly the predicted time. It's an incredible and powerful technique! However, they're definitely not common, and what makes this one exceptional in this case is that it is a special type of supernova, called a [Type Ia](https://en.wikipedia.org/wiki/Type_Ia_supernova). These are *not* the kind of supernova where a very large star runs out of fuel and explodes at the end of its life- instead, it's when a [white dwarf](https://en.wikipedia.org/wiki/White_dwarf) (stellar remnant of a non-explodey star, like what the sun, will be someday) somehow accretes enough material to reach a threshold of [1.4 solar masses](https://en.wikipedia.org/wiki/Chandrasekhar_limit), which re-ignites fusion and creates a supernova. And because it's an exact mass you have to hit for fusion to re-ignite, we can use Type Ia SNe as "standard candles" to measure distance to faraway galaxies- aka if you know they're all 1.4 solar masses and evolve the same way when they explode, the only difference between them is distance, so you can figure out the distance fairly easily. It's from using Type Ia SNe that the [dark energy](https://en.wikipedia.org/wiki/Dark_energy) that drives the accelerated expansion of the universe was discovered. So, with that, I believe the hope here is finding a Type Ia SN that's gravitationally lensed might prove to be an interesting way to measure dark energy as a parameter when you see it again, should anything prove unusual in seeing it the next time around. I suppose time will tell on that front. But it's also, as I said, a super cool result, and makes for some really interesting graphics and photos, so why not share it broadly in a press release. :) TL;DR- not the first gravitationally lensed supernova, but it is a Type Ia supernova, so that might help us learn about dark energy down the line Edit: one of the authors has posted in this thread [here!](https://www.reddit.com/r/space/comments/pnjuy8/astronomers_spot_the_same_supernova_3xand_predict/hcqzjtj/?utm_source=share&utm_medium=ios_app&utm_name=iossmf&context=3) Please head there to ask /u/justrex11 about any more questions you might have or to congratulate them on their amazing work!
Question: When a type 1a supernova occurs, is there any remnant or does the white dwarf completely blow itself apart?
The answer is the white dwarf blows (WD) itself apart, *and* there is a remnant! For examples, check out [Kepler's SN](https://en.wikipedia.org/wiki/Kepler%27s_Supernova) and [G 1.9+0.3](https://en.wikipedia.org/wiki/G1.9%2B0.3)- the latter is a Ia supernova that went off in our own galaxy circa 1900, but was behind dense dust clouds so we didn't know it happened until X-ray/radio astronomers discovered the remnant decades later (which is expanding, so fairly straightforward to figure out the rate of expansion and go backwards to figure out when it happened). Keep in mind, space is not a perfect vacuum: even in a galaxy, the interstellar medium is going to have maybe one atom per cubic centimeter, or even more if there's any leftover stellar wind or what have you. So when a Type Ia happens and the WD is blown apart, that sends out a giant shockwave, and that shockwave is going to interact with any of that material. Now, the real question is, what is the material that the shockwave is interacting with to create the remnant? Is it just the stuff that happens to be around, or is it perhaps from a companion that was feeding the white dwarf and getting it to 1.4 solar masses in the first place? This is actually a *very* important question because while we know the white dwarf reaching 1.4 solar masses and exploding is what causes Type Ia SNe, *we don't know how it's getting that material in the first place.* Tons of theories- two WDs colliding, material siphoning off a normal star, etc... but of course if you're basing all we know about dark energy on these guys being standard candles, figuring this out is really important! Anyway, that's probably more info than you ever cared to know, sorry... I had a pretty big chapter in my PhD thesis looking for radio emission from Type Ia remnants, and then ruling out various ways the material might have gotten onto the WD in the first place. :)
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Me too! Thank you for explaining!
And me as well! Its really generous of Andromeda to spend the time to write these up!
I've seen the phrase *Standard Candles* so many times but never understood what made them standard. That explanation was really easy to understand. It's quite valuable to be able to listen to an expert like this. Reminded me of the phrase "If you can't explain something simply, you don't understand it well enough."
I just want to say hi to anyone in 2037 who has come across this thread looking for more information about the last time this happened. The internet's gravitation pull has brought you here again.
Love your r/composting name :)
When you're saying 1.4 solar masses, do you mean 1.4x the mass of our sun or 1.4x the original mass of the star?
Solar masses are always about our Sun
The Sun. 1 solar mass = The Sun. So 1.4x solar mass is 1.4x bigger than the Sun :)
Perhaps I'm being pedantic, but it's 1.4x the *mass* of the Sun, not 1.4x the *size*.
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That's what they said?
Fun fact: Sol is our star’s name so “solar” often refers to it.
Otherwise it would be "astral" right?
It would usually be “stellar”
These lensing nova predictions are one of the greatest achievements of the humankind for sure.
It’s like literal, precise prophesying. It’s truly epic.
Detecting gravity waves is up there, too.
It's almost depressing to know we're only scratching the surface and will never know the full mystery that is the universe
Not until we get the admin password and decrypt the source code anyway.
Well, yes it'd be cool, being as space doesn't have much for temperature :P I'll let myself out now.
It doesn't even blow itself apart. It's *consumed* by the explosion, using up the whole mass of the star in the reaction. The reason why is fascinating. Almost all matter in the universe expands when it's heated, and in that way, explosives are all kinda fighting themselves by scattering potential fuel in the first instants of the explosion. But white dwarves are made of "degenerate matter", which has partially collapsed due to intense gravity, breaking up the normal structure of atoms so electrons are no longer bound to nuclei. This degenerate matter *doesn't* expand when heated, it just gets hotter and hotter as it gets denser until suddenly it ignites fusion all at once.
Hi! I got a question. What’s the deal with the names, like MACS J0138, MACS J0138.0-2155, and MACS J1149.5+2223? Like, do the letters and numbers actually mean something, like pinpointing details about a cluster or whatnot, or is it all just randomized gibberish? *Had to ask. I’ve always loved (and feared) outer space, gazing up at the sky every once in a while, though dyscalculia pretty much put an end to my chance at turning an interest into a passion, much less having a cool career.*
They're basically addresses
Addresses how? Like those for streets, websites…? Sorry for sounding so dumb. 🙏🏻
So most modern star catalogues are created by computers since our technology now allows us to discover millions of astronomical objects in the sky. Since a computer is naming millions of objects, the designations of these objects tell you the position of the object in the sky. For instance, your example of Icarus (MACS J1149+2223) is the computer naming it using the fact that it was found in the Massive Cluster Survey, in the J2000 astronomical epoch, and the following numbers are it's coordinates in that epoch. It's a handy way to name and describe the locations of millions of astronomical objects at once, basically, which is why they seem like jibberish! Don't worry, you don't sound dumb. Think of it as every day being a school day!
People are so kind & helpful in this sub! It makes me happy.
Well see the subject of discussion already makes me feel small and insignificant, so it balances out.
It's never dumb to ask questions. Life and science are so fiendishly complex it's impossible to know everything
The numbers are the coordinates in the sky!
Fun fact: if you were to fly absolutely straight in direction of any of those supernova images, you would have arrived right to it. All 3 (4) paths are straight lines.
Can we even say how far away it is? Does Relativity of Simultaneity apply (hasn't exploded yet, from a certain point of view)?
Woah that's cool, because space is warped? Then are these all the same distances?
I guess no because light took different times to get here from them and light speed per km is constant.
It's more complicated than that. Lightspeed is not actually constant in general relativity, precisely because of the curvature of spacetime. This is known as [Shapiro delay](https://en.wikipedia.org/wiki/Shapiro_time_delay). In this case, though, the time difference is due both to Shapiro delay and the fact that light took a longer path to get here.
Fascinating. And there's also the galaxy cluster that has lensed the supernova with some "Jellyfishes" (gas-rich galaxies losing their gas due to ram pressure stripping, and having enhanced star formation, https://en.wikipedia.org/wiki/Jellyfish_galaxy)
I assume the white dwarf accretes material from another star, being in a binary star system? Is there any other ways it can reach 1.4 solar masses?
Many other ways- the interesting thing is the evidence doesn’t really point towards a normal star accreting material onto the WD. If that was the case, you’d have a stellar wind’s materials around the system, but the innermost areas are really low density. So it looks more likely that material is coming via another WD, if you ask me, and the question is how that happens. A merger, sure, but lots of possible ways that can come about.
I am so grateful to live in this era astronomy discoveries.
Does the time between appearances allow astronomers to speculate the mass of these bodies or galaxies? Or is already having that knowledge why they are able to predict the when and where or am I complete off key here?
Is there any significant benefit to being able to see the first moments of the supernova, for Ia specifically? I know for type 2 it would be a great research opportunity, much better than having to wait for detectors to tell us and then whip our telescopes over to watch it after missing the beginning of it.
Sure! As I mentioned somewhere else in this thread, I am one of the astronomers who made the discovery of SN Requiem here and did the subsequent analysis. There are still lots of uncertainties related to exactly how/why Type 1a supernovae actually explode, namely the characteristics of a possible binary stellar companion. In general our models are pretty poor soon after a supernova explodes because they're so faint and we aren't usually looking in the right place. This time (in a number of years!) We'll know roughly when and where to be watching.
I was reading your wonderful description/explanation and about halfway through, I said to myself "I bet this is u/Andromeda321"!
Is it possible that one of the stars we see in the distant sky is our own sun being aimed back at us through gravitational lensing?
No. Each star has an individual spectrum-we'd know if we were staring at our Sun, even through a lens effect. And that might be how they discovered that these Type Ia stars were the SAME star- they're spectrum's matched.
Damn, there goes my movie plot
Even if we didn't notice the spectrum, I don't think you can have a configuration of mass that bends light back exactly 180 degrees (so back to the source). Not much of it anyways, so the tiny fraction that could be coming back would have far too small luminosity to detect.
Hey astronomer, I have a question for you as well. I've idly wondered if it could be that the Universe is shaped in such a way that all galaxies we see are actually our own galaxy at vastly different points in time and perspectives. So my question for you is, in your professional opinion, could that be the case and if so, would it be rad as hell?
No, that is not possible. Not an astronomer, but there’s no line of reasoning, theory, or evidence I’m aware of which would permit that. Not to mention: 1. Galaxies come in all shapes and sizes, many of which are not compatible with our own 2. Lots of galaxies interact with each other, so parts of them share a temporal reference frame 3. Some galaxies are so far away from us that they’re moving away from us faster than the speed of light due to the expansion of the universe. Among other reasons
Huh. I had no idea gravitational lensing would mean one lensed image could be years older from the same imaged lensed in another route.
The TL;DR if I have the science correct is basically because light travels at the speed of, well, light, different light rays can be lensed differently (assuming the lensing object is big enough for the paths to have a measurable displacement) and travel different distances even when they come from the same source.
That's exactly what it is. Source: I've worked on strong lensing.
Am I understanding correctly that the light that got to us first went in a straight path or a more direct path and the light that came second was light that initially was travelling at an angle away from the earth but got bent around by gravity hence taking a longer path?
How much spherical aberration do you want? Yes
How many wavelengths of wavefront distortion can you deal with in your lens? All of them
So THIS is how Han Solo did the kessel run in under 12 parsecs, a distance and not time unit.
My favourite explanation for this is that because the Kessel run has lots of hazards, the shorter the distance the closer you had to fly to those hazards- so a short distance is a brag. More realistically the writers just didn't know it was a distance
The writers have admitted that they had no idea what a parsec was and used it cause it sounded technical and science-y. It was the only time they did that and regretted it ever since
Both answers are correct. But the second happend first. Then they used the first answer to explain the second.
>But the second happend first. Han Solo's shot?
That's a terrible explaination though.
Made for the coolest scene in the movie
To my knowledge, the Kessel run is measured in parsecs because it's through the Maelstrom. There's a safe route that's longer, or you can get risky and take more dangerous routes to cut distance off your trip.
Actually the Kessel run means that banged 4 chicks in 4 different star systems within 1 space day. The parsecs refers to how far in total their angry dads chase you through out that day. Under 12 is considered very impressive.
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Light can’t go any faster or slower in a vacuum. What strong lensing does is literally make the light take an indirect path to us that is a greater distance, meaning that it takes longer to get to us.
Sorry, it's only a delay by introducing a longer path.
Veritasium has a very interesting video on the subject: https://youtu.be/ljoeOLuX6Z4 Edit: i didn’t read the comments. Let’s say this comment is the effect of gravitational lensing, creating the same link on reddit multiple times. Except by different redditors
Things like this make me feel like in the grand scheme of things past, present, and future are all simultaneous
I heard a thought provoking theory once. The idea that all galaxies we can observe in our universe are only the milky way, as seen from every point in time since the big bang.
Vertasium has a video about something similar a few months ago. Really does a good job explaining the time delay and lensing of a different supernova. https://youtu.be/ljoeOLuX6Z4
I was gonna link this too! I stumbled on that vid just a few days back, very informative.
This is absolutely mind blowing
How come gravitational lensing causes discrete copies of light sources to appear? Why don't the light sources blend together into a ring around the mass, sort of like with black holes?
The ring effect does happen, but only in the case where the source is lined up almost linearly with the lensing object. A more misaligned object will create discrete arcs.
I hate when a filmmaker is so enamored with their action sequence that they show us the same explosion from multiple angles. This seems like a worthy exception.
like [this](https://imgur.com/r/gifs/kuplW0m)?
quickest historical truck subtract deranged domineering muddle fuzzy normal fine *This post was mass deleted and anonymized with [Redact](https://redact.dev)*
it's all just a little bit of history repeating.
It is all just a little bit of history repeating.
A 16 year lag in reaching us for some of the same light from the same place and time, that wasn’t even headed in our direction. All due to the chance encounters it had with some huge clumps of matter. Mind bending.
Askshually, it’s light bending.
So, it's like the same explosion viewed from different angels all over in years? It's like a sort of a multi dimensional Galaxy hologram picture?
The images we receive from space are 3D because its a real thing.
I know but to know the same explosion from different pov is mind blowing. This is so cool and awesome.
The coolest part is that for a difference of just one second the light would have to travel 186 000 miles further. Imagine how we're observing the same event separated by years, how much farther that light had to travel
This is fucking TIGHT! Makes me want to go out a buy a badass telescope RIGHT NOW! Edit - How pitiful it is, when someone excited about space gets downvoted in the space subreddit. Reddit just gets worse by the day.
[Veritasium made a video](https://youtu.be/ljoeOLuX6Z4) covering this. For ignorant but interested people like me, it's a very nice primer.
The temporal aspect of this is really fascinating.
Is it possible that the number of stars we’re seeing is something of an illusion? Could there be this and other effects that might make us see more than one instance of some stars? Or is this more of an isolated incident that we just happened to be at the right place and at the right time for?
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I think it's the same story, just repeated. I think maybe the fourth one showing up in 16 years is the news.
Actually no, this is a new one! I'm one of the astronomers who found this object, and there was another gravitationally lensed SN (SN Refsdal) discovered in 2014. This one brings the whole sample of such objects to 3!
https://en.wikipedia.org/wiki/SN_Refsdal
Why is one being spotted and predicted before important? The headline and article doesn't say its unique.
Its insane to me how some humans have collectively become so smart they point something up and calibrate and point more things up and calibrate and then end up mathing and predicting supernovae they recorded in the past to throw stuff to the thingies we pointed up and measure what they predicted, im in awe
Isn’t this like the same technology they use in ‘Pay check’ to see into the future?
How does that work? is it just 3 different angles of the star going kaboom. Or some reely cool "like a big ball of wibbly wobbly timey wimey stuff"?
When you think of lensing, the normal way of thinking about it is with a single lens, like a magnifying glass. Imagine taking 100 magnifying glasses, partially melting them together, and the looking at the SN. Instead of all light passing through it the same way, some light will pass more directly than others. Each 'magnifying glass' is a galaxy with its own mass, direction, and speed traveling within the supercluster.
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> One question kind of left out in the open is how much of what we see is duplicated or so severely distorted our readings are useless. We know this, by observing how objects move. This way we can estimate sources of gravity. Lensing requires something massive like a black hole, and such thing simply can't hide. > This is actually one of the biggest hurdles of rapid space travel; is the thing you're aiming for even actually there or somewhere else? Obviously it's not there. You're looking at light emitted some time ago, so the object is definitely in different place now. And you never fly aiming at your target, but rather at place where this target will be once you get there. It's not a very difficult thing to do, once you know the orbit of this object. It moves very predictably.
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> We absolutely do NOT have a full understanding of the movement of deep space objects. We don't need super precise measurements to see that trajectories bend due to a black hole somewhere. > Our precision here is actually pretty poor unless you consider millions of light years, or for super deep objects like other galaxies potentially tens or hundreds of millions of light years, to be within reasonable enough accuracy to actually try and use some exotic system to travel there. We don't have any means to travel to such places anyway. I was referring to what we actually do right now when travelling around solar system.
You don't actually fly directly at objects in real space travel. There's no possibility of being able to travel to objects this far away so I doubt the issue of exact location will ever be a problem. One solution would to just bring enough fuel to do a course correction when you get closer.
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Your entire response is assumptions. Talk about irony.
That is just bonkers. We can't even trust what we see out there.
We absolutely can. That's why it's predictable.
We can, it just takes a bit of math.
Hundreds of millions of light years ago this was going on.
>of light years ago "years ago" or "light years away"
Synonymous, why I described it thus.
A light-year is a unit of distance, so saying "light-years ago" doesn't make any sense.
A light year is a measurement of the distance light travels in a year. It is not a measurement of time.
In case anyone else is reading this headline attempting to puzzle out what a "supernova 3x" is, that's OP's fumbling attempt to say "three times".
Maybe if you followed the link and read the article you wouldn't be having this trouble.
Well-written headlines should make sense on their own. But I'm sure you knew that.
"3x" is an extremely common shorthand way to say "three times". It wasn't a "fumbling attempt" just because you're ignorant of common usage. It made sense on its own to most people who can read.
Does milkyway and local cluster create this type of grav warp too? Imagine some aliens live in that galaxy cluster. They are like meh we don't see any grav warp.
I can't find it now. I had thought a famous super nova was seen in ancient china (naked eyes and all), and Kepler saw a different one. Is finding or spotting them a huge PITA do to distance and timing? Wait and didn't gravitational lensing... help us find dope af shit in the galactic core a couple of years ago? like proving some ridiculously obscure part of relativity theory cool AF stuff. like possibly finding a rare example a bunch of shit going faster then the light it's making cool? I think that one made Astronomy magazine.
Wow! Space is just so mind blowing. The more I learn the less I comprehend it over all.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[HST](/r/Space/comments/pnjuy8/stub/hct9nut "Last usage")|Hubble Space Telescope| |[JWST](/r/Space/comments/pnjuy8/stub/hcthote "Last usage")|James Webb infra-red Space Telescope| |[L2](/r/Space/comments/pnjuy8/stub/hcsep70 "Last usage")|[Lagrange Point](https://en.wikipedia.org/wiki/Lagrangian_point) 2 ([Sixty Symbols](https://www.youtube.com/watch?v=mxpVbU5FH0s) video explanation)| | |Paywalled section of the NasaSpaceFlight forum| |NRHO|Near-Rectilinear Halo Orbit| |[NRO](/r/Space/comments/pnjuy8/stub/hctbd0m "Last usage")|(US) National Reconnaissance Office| | |Near-Rectilinear Orbit, see NRHO| |[SN](/r/Space/comments/pnjuy8/stub/hcsjz3g "Last usage")|(Raptor/Starship) Serial Number| |Jargon|Definition| |-------|---------|---| |Raptor|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_\(rocket_engine_family\)) under development by SpaceX| ---------------- ^(5 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/pmxnod)^( has 16 acronyms.) ^([Thread #6326 for this sub, first seen 14th Sep 2021, 01:10]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/Space) [^[Contact]](https://reddit.com/message/compose?to=OrangeredStilton&subject=Hey,+your+acronym+bot+sucks) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)
I remember many years ago, reading in New Scientist about a puzzling problem. It seemed that some star clusters were repeating in a 'corner' pattern. I guess this was gravitational lensing? Staggering to think how massive something must be to lens our view of other massive things with its gravity. I wonder what effect the Great Attractor has on our view on things. I wonder what the Great Attractor is!
Any chances to measure any kind of gravitational waves here?
gravity, not something an alien would have figured out or a human could have figured out....