[HN Gopher] Vera C. Rubin Observatory first images
___________________________________________________________________
Vera C. Rubin Observatory first images
Author : phsilva
Score : 556 points
Date : 2025-06-23 15:41 UTC (1 days ago)
(HTM) web link (rubinobservatory.org)
(TXT) w3m dump (rubinobservatory.org)
| phsilva wrote:
| https://skyviewer.app/
| spacecadet wrote:
| We got DOGE instead of using $100k of tax dollars making this
| into a super nice public mobile app...
| aragilar wrote:
| While it would be cool to make a mobile app for this, having
| used both the tech stack behind this site (it's open source,
| and really great), and written a mobile app with a similar
| tech stack, $100k will get you one, but it's going to be a
| pain to debug all the various niggles around various devices,
| so you'll need at least double that to make a robust one (and
| then the question is, do you just go native and reimplement
| that tech stack).
| spacecadet wrote:
| Im not typically this person, but hacker news is just more
| and more "allow me to tell you", buddy I have 20 years
| experience building mobile apps... including against
| scientific, open source, and plain old hack-AF platforms...
| NitpickLawyer wrote:
| So stoked for this observatory to go online! One cool uses it'll
| excel at is taking "deltas" between images and detect moving
| stuff. Close asteroids is one obvious goal, but I'm more
| interested in the next Oumuamua / Borisov like objects that come
| in from interstellar space. It would be amazing to get early
| warnings about those, and be able to study them with other
| powerful telescopes we have now.
| avmich wrote:
| > So stoked for this observatory to go online!
|
| Second this, but other areas are of great interest too. Kuiper
| Belt discoveries and surveys FTW!
| jasonthorsness wrote:
| Why are there lens-flare-like artifacts around some of the bright
| objects?
| NitpickLawyer wrote:
| Those are diffraction spikes, caused by how the light interacts
| with the support structure holding the secondary mirror. Each
| telescope has different patterns, hubble, jwst, etc. I think
| they only happen for stars, and not for galaxies (an easy way
| to know which is which), but I might be wrong on that (there's
| a possibility for faint stars not to have them IIRC).
| perihelions wrote:
| > _" Each telescope has different patterns"_
|
| This one's extra-special! The pattern is multiple + shapes,
| rotated and superimposed on top of each other. _And they 're
| different colors!_ That's this telescope's signature scanning
| algorithm--I don't know what that is, but, it's evident it
| takes multiple exposures, in different color filters, with
| the image plane rotated differently relative to the CCD plane
| in each exposure. I assume there's some kind of signal
| processing rationale behind that choice.
|
| edit: Here's one of the bright stars, I think it's HD 107428:
|
| https://i.ibb.co/HTmP0rqn/diffraction.webp
|
| This one has asteroid streaks surrounding it (it's a toggle
| in one of the hidden menus), which gives a strong clue about
| the timing of the multiple exposures. The asteroids are going
| in a straight line at a constant speed--the spacing and
| colors of the dots shows what the exposure sequence was.
|
| I think this quote explains the reason they want to rotate
| the camera:
|
| > _" The ranking criteria also ensure that the visits to each
| field are widely distributed in position angle on the sky and
| rotation angle of the camera in order to minimize systematic
| effects in galaxy shape determination."_
|
| https://arxiv.org/abs/0805.2366 ( _" LSST [Vera Rubin]: from
| Science Drivers to Reference Design and Anticipated Data
| Products"_)
| nullc wrote:
| > with the image plane rotated differently relative to the
| CCD plane in each exposure
|
| LSST is a alt/az telescope. The earth rotates. The sensor
| plane must rotate during the exposure to prevent stars from
| streaking, which it accomplishes via this platform: https:/
| /docushare.lsstcorp.org/docushare/dsweb/Get/Document-...
|
| The fact that the sensor rotates without the spider
| rotating also spreads out the diffraction spikes.
|
| But that rotation is limited, so between different
| exposures with different filters the image plane will be
| rotated relative to the sky.
|
| As the quote goes the change in orientation has benefits
| for controlling systematics..
| IAmBroom wrote:
| No, they happen for absolutely every externally-generated
| pixel of light (that is, not for shot noise, or firelflies
| that happen to fly between the mirrors). Where objects
| subtend more than one pixel, each pixel will generate it's
| own diffraction patterns, and the superposition of all are
| present in the final image. Of course, each diffraction
| pattern is offset from the next, so they mostly just broaden
| (smear out), not intensify.
|
| However, the brightness of the diffraction effects is much
| lower than the light of the focused image itself. Where the
| image is itself dim, the diffraction effects might not add up
| to anything noticeable. Where the image supersaturates the
| detector (as can happen with a 1-pixel-wide star), the "much
| lower" fraction of that intensity can still be annoyingly
| visible.
| aragilar wrote:
| It depends on the science you're doing as even these small
| effects add up, there's a project within the LSST science
| team (which a college is working on) to reduce this
| scattered light (search for "low surface brightness"),
| where there's a whole lot of work around modelling and
| understanding what effect the telescope system on the
| idealised single point that is a star.
|
| There are projects (dragonfly and huntsman are the ones I
| know of) which avoid using mirrors and instead use lenses
| (which have their own issues) to reduce this scattered
| light.
| petee wrote:
| The same effect is used for Bahtinov focusing masks. From
| what i know, all light will bend around the structures, but
| stars are bright and focused enough to see; in theory
| galaxies would too
| naasking wrote:
| Diffraction spikes [1] are a natural result of the wave-like
| nature of light, so they occur for all objects viewed through
| a telescope, and the exact pattern depends on the number and
| thickness of the vanes.
|
| My favourite fact about these in relation to astronomy is
| that you can actually get rid of the diffraction spikes if
| your support vanes are curved, which ends up smearing out the
| diffraction pattern over a larger area [2]. However this is
| often _not_ what you want in professional astronomy, because
| the smeared light can obscure faint objects you might want to
| see, like moons orbiting planets, planets orbiting stars, or
| lensed objects behind galaxies in deep space. So you often
| want sharp, crisp diffraction spikes so you can resolve these
| faint objects next to or behind the bright object that 's up
| front.
|
| [1] https://www.celestron.com/blogs/knowledgebase/what-is-a-
| diff...
|
| [2] https://www.fpi-protostar.com/img/spikes.gif
| pantalaimon wrote:
| Those are stars, they create those lens flares because they are
| so bright.
|
| All the dim fuzzy objects are galaxies much further away.
| perihelions wrote:
| Here's the SDSS view[0] of this featured[1] section from the
| Virgo Cluster, in comparison, to put the staggering depth of
| these exposures in their proper context,
|
| [0]
| https://aladin.cds.unistra.fr/AladinLite/?target=12%2026%205...
|
| [1] https://rubinobservatory.org/gallery/collections/first-
| look-...
| tominspace7 wrote:
| With an opacity slider, for easy comparison:
|
| https://aladin.cds.unistra.fr/AladinLite/?baseImageLayer=CDS...
| sega_sai wrote:
| Thanks for the link, I didn't know one can do this with
| Aladin Lite! But to be fair, if we compare to DESI LS, it
| looks much less impressive. I.e. all the shells/tidal debris
| are basically visible in DESI.
| tominspace7 wrote:
| Agreed. Here is the link: https://aladin.cds.unistra.fr/Ala
| dinLite/?baseImageLayer=CDS...
| binarystargazer wrote:
| I agree their results are also great! We do go a bit
| deeper, but he big difference it the speed we are able to
| build these images. We are able to image a larger area of
| the sky in each exposure, and are able to collect more
| light. This will lets us build images like this one in a
| few hours of observation, and build up an equivalent image
| of the entire southern hemisphere.
| dekhn wrote:
| I really like the Rubin because I think a lot of people focus too
| much on "deep" seeing (IE, looking at individual or several
| objects with very high magnification only once). The Rubin does
| much more "wide" seeing and this actually produces a ton of
| useful data- basically, enough data to collect reliable
| statistics about things. This helps refine cosmological models in
| ways that smaller individual observations cannot.
|
| What's amazing to me is just how long it took to get to first
| photo- I was working on the design of the LSST scope well over 10
| years ago, and the project had been underway for some time before
| that. It's hard to keep attention on projects for that long when
| a company can IPO and make billions in just a few years.
| cogman10 wrote:
| Deep is still interesting in understanding the origins of the
| universe. Rubin seems highly practical on the flip side. It'll
| be a super helpful tool in predicting asteroid impacts.
| TheBlight wrote:
| Or detecting more unusual interstellar objects like
| 'Oumuamua.
| WD-42 wrote:
| Also microlensing events, supernovae, and many other things
| in our very dynamic universe.
| perihelions wrote:
| Also new planets! Planet Nine should likely be resolved
| within months, one way or another.
|
| > _" Probably within the first year we're going to see if
| there's something there or not," says Pedro Bernardinelli,
| an astronomer at the University of Washington."_
|
| https://www.nationalgeographic.com/science/article/is-
| there-...
| sdafi239 wrote:
| nice
| erikerikson wrote:
| Welcome to Hacker News!
|
| It is generally recommended to upvote a comment you
| appreciate rather than making a comment that isn't adding
| substance. It helps keep the signal rate higher.
| prpl wrote:
| It does wide through image stacking/repeated visits. The speed
| and FOV is the key here.
| prpl wrote:
| Too late to edit - I meant Deep.
| grues-dinner wrote:
| Speaking of wide-fields, check out the Xuntian space telescope,
| which has (will have) a 1.1 degree field of view and a 2.5
| gigapixel camera.
| DiogenesKynikos wrote:
| The "wide" mode is called "survey" astronomy, and there have
| been several large surveys like Rubin/LSST, going all the way
| back to the Sloan Digital Sky Survey, which started in 2000 (if
| you count surveys from before the era of digital sensors, there
| are surveys going back more than 100 years).[0] Rubin/LSST is
| just the newest and most advanced large, ground-based optical
| survey.
|
| Both modes of observation - surveys and targeted observations
| of individual objects - are necessary for astronomical
| research. Often, large surveys are used to scan the sky, and
| then targeted observations are used to follow up on the most
| interesting objects.
|
| 0. https://en.wikipedia.org/wiki/Sloan_Digital_Sky_Survey
|
| Note that "seeing" means something very specific in astronomy:
| https://en.wikipedia.org/wiki/Astronomical_seeing.
| aragilar wrote:
| My feeling is the "deep" vs "wide" thing is a circumstance of
| which groups you interact with (and also which facilities you
| have access to, and even to some extent the culture of your
| science community). Rubin is an example of what you can do when
| you build something massive specifically for a single purpose,
| and as more of these kind of facilities come online (SDSS and
| Gaia have been around for a while, but DESI, 4MOST and other
| similar facilities are coming, and let's not forget radio),
| it's what we get out of the whole suite supporting each other
| that gets the best science.
| jpizagno wrote:
| You worked on the design? That is interesting. I worked on the
| simulating the LSST , back in 2008 to 2010. The goal of which
| was to test the data reduction software. We were on the Image
| Simulation team.
|
| It is surreal to see LSST/Rubin finally get first light.
|
| Even more interesting to see who is still working on LSST, and
| who is not.
| dekhn wrote:
| We also simulated the LSST- in this case, using Exacycle at
| google (an idle cycle harvester). We took a star catalog and
| passed it through a highly accurate ray tracer that simulated
| the light falling on the sensors (through space, atmosphere,
| etc). Apparently it found some bug in the design that was
| fixed before some expensive part was built (my coworkers were
| the subject matter expert, I mainly built the exacycle
| software and sat in on the meetings).
| KurSix wrote:
| It's not just about pretty pictures (though those are great),
| it's about building massive datasets that let us actually do
| statistics on the universe
| krunck wrote:
| The asteroid detection capability is amazing:
| https://rubinobservatory.org/news/rubin-first-look/swarm-ast...
| cogman10 wrote:
| This is really going to revolutionize our ability to detect and
| predict asteroid impact.
| stronglikedan wrote:
| And just in the nick of time!
| jstummbillig wrote:
| That is likely the most unexcitedly unsettling video I have
| ever seen. Amazing storytelling really.
| stronglikedan wrote:
| I was just coming back to comment on the existential dread
| elicited by that video.
| semireg wrote:
| It's like swimming in a lake or river and thinking the water
| is just water but then you take a closer look and it's just
| incredibly alive to the point of absurdity.
| steve_adams_86 wrote:
| I suppose the weeds, bugs, bacteria, frogs, fish, and
| snakes are equally unlikely to harm us, but nonetheless.
| Holy shit!
| m3kw9 wrote:
| Which also tells the astronomical low odds of asteroids hitting
| earth even with "so many" of them. To me it changes nothing
| bjt wrote:
| If it has the potential to wipe out our entire species, but
| there's something we could do to prevent it (which I'm not
| sure about w/r/to asteroids), then it's worth looking out for
| the black swan event.
|
| Doing some extremely rough math along these lines to double
| check myself:
|
| * Gemini says that a dinosaur-extincting asteroid hits Earth
| about once every 100 million years. So in any given year
| that's 0.000001%.
|
| * Economists say a human life is worth about 10 million
| dollars. There are about 8 billion people on Earth. So the
| total value of all human life is $80,000,000,000,000,000 (or
| 8e+16).
|
| * So in any given year, the present value of asteroid
| protection is $800,000,000 (likelihood of an impact that year
| times value of the human life it would wipe out).
|
| * The Guardian says the Vera Rubin telescope cost about
| $2,000,000,000 (2 billion).
|
| By that measure, assuming the Rubin telescope prevents any
| dinosaur-extinction-level asteroid impacts, it will pay for
| itself in three years.
|
| https://www.npr.org/transcripts/835571843
| myrmidon wrote:
| These numbers are not what I expected at all.
|
| So you could actually make an argument that to a country
| like the US, full 100% reliable asteroid protection is only
| worth like $50M/year (even if an impact means _full_
| extinction)?
|
| So if upkeep for a detection/deflection system costs more
| than that we'd be "better off" just risking it?! Thats
| insane. I would have expected this number to be _much_
| higher than $50M /year.
| andruby wrote:
| The economists calculated the value of 1 life. The
| calculation might be different if it extinguishes the
| whole of humanity (and thousands of other species). In a
| way, it also presents all future human lives. Should we
| include those?
| myrmidon wrote:
| I don't believe that this would change the outcome much:
| It seems hard to argue that preservation of a nonhuman
| species would be worth more than a million lives (=>
| negligible) and assuming global loss of all human life is
| already unreasonably pessimistic in my view-- (e.g. the
| Chicxulub impactor would not have achieved this).
|
| I also think that fully accounting for multi-generational
| consequences is murky/questionable and not really
| something we do even in much more obvious cases: Eligible
| people deciding against having children are not punished
| for depriving future society of centuries of expected
| workyears, and neither are mothers/fathers rewarded for
| the reverse.
|
| But even if you accounted for losing 3 full generations
| and some change (for biodiversity loss), that still
| leaves you in the ~$200M/year range.
|
| Currently we don't have reliable asteroid deflection
| capability at _any_ price (but it would be technically
| somewhat in reach), but just imagine a future NASA budget
| discussion that goes "we're gonna have to mothball our
| asteroid deflector 3000 because it eats 5% of yearly NASA
| budget and thats just not worth it"-- that could be the
| mathematically correct choice, which confounds me.
| cogman10 wrote:
| I think where the calculations are breaking down is in
| the probability of asteroid strikes.
|
| All the math assumes that the probabilities will follow
| historic trends and is relatively static. With single
| digit events, we really have no way in knowing what the
| actual likelihood of impact is. It could be 1 in 100
| million, it could actually be 1 in 1 million and we've
| been rolling a bunch of nat 20s.
|
| Before we build out the asteroid blaster 9000, the first
| step is detection. With that in place then we get actual
| good risk and probability calculations. If the detector
| tells us "There's no object that will strike earth in the
| next 1000 years" we can safely not put any budget into
| asteroid defense. If, on the other hand, the detector
| shows "Chicxulub 2.0 will hit in the next 100 years" then
| your probability of an impact is 1 and the actual budget
| worth it is going to be much closer to that $8e+16 number
| calculated earlier.
| myrmidon wrote:
| I agree that detection is a very helpful first step and
| almost enough on its own. But I'm unsure how far this can
| be pushed-- I think impact certainty for a century or
| more might be physically impossible, because of
| uncertainty in orbital parameters and chaotic behavior of
| the whole system.
|
| I also believe the approximate bounds we have on impact
| probability are good enough for this estimate and quite
| unlikely to be off by a factor of 100, because we can
| guess at both size distribution and impact likelihood
| from craters (on earth and moon), and if the >10km object
| impact likelihood was over 1/million years we would
| expect to see a hundred times more craters of the
| corresponding size...
| cogman10 wrote:
| > I think impact certainty for a century or more might be
| physically impossible, because of uncertainty in orbital
| parameters and chaotic behavior of the whole system.
|
| We already have 10s of years of certainty with the
| current observations. Most of the uncertainty comes from
| the interactions of unknown objects. As the mappings of
| objects increase, our predictions will become much
| better.
|
| The other thing to consider is that large objects will
| have much better certainty. A 10km asteroid won't be
| influenced (much) by colliding with 100 1m asteroids. It
| will only be impacted if it hits or swings by something
| like a 1km asteroid.
|
| Rubin should in a pretty short timeframe (a few years)
| give us an orbital mapping of all the >1km asteroids,
| which is pretty exciting.
| mapt wrote:
| While I'm strongly supportive of survey astronomy in
| general...
|
| We can already say that we have very high completion of
| cataloguing near-Earth objects that are anywhere near
| extinction-event / Chicxulub-sized (~10km), and have a
| majority of catastrophic / country-killer (~1km), and are
| digging deeper and deeper into regional / city-killer
| (~100m) bodies.
|
| What we don't have is comets. Comets on long period
| orbits just aren't readily detectable with this sort of
| survey unless they're quite close in to the Sun, and I
| don't think we have great statistics on frequency vs
| size, size being something that requires very specific
| radar cross-checking to establish with any confidence. A
| long-period comet or hyperbolic body has a potential
| impact velocity much higher than inner system asteroids,
| and impact energy scales with impact velocity squared.
| cogman10 wrote:
| Will rubin detect comets? I'd assume not as it seems like
| they'll only really be visible as they approach the sun
| (or if they end up blocking a line of stars).
| mapt wrote:
| The problem is that the difference in optical/NIR
| brightness (apparent magnitude) between a long-period
| comet core that's going to hit us in 1000 years, and a
| long-period comet core that's going to hit us in six
| months, might be a factor 10^12 (magnitude 10 vs
| magnitude 40) or worse. Normally brightness drops off
| with distance squared for light sources, but comets
| without any tail or halo aren't emitting all that much
| light, they're reflecting it, and (except for a very
| brief period) they're about as far from us as they are
| from the sun. This means that brightness drops with
| distance to the fourth power. Cometary tails also only
| offgas a significant amount near the sun. Comet cores are
| expected to be extremely dark / low-reflectivity due to
| space weathering producing a carbon coating not unlike
| chimney-creosote.
|
| You can fight this a bit by working in the thermal
| infrared, which you really need a specific sort of space
| telescope for. But long-period comets and hyperbolic
| impactors will be a probabilistic threat for the
| foreseeable future. I would say "Be thankful that they're
| so rare", but the data from observatories like Rubin on
| these bodies during points of their orbit where they're
| close enough to the sun to actually detect, is necessary
| to statistically characterize their existence with any
| confidence.
| adgjlsfhk1 wrote:
| one thing this analysis is missing is the smaller
| asteroids. for every planet altering asteroid, there are
| hundreds that could cause a tsunami that would wipe out a
| few cities
| myrmidon wrote:
| Good point, but I think those are "worth" less from a
| risk-analysis PoV: 1km diameter is apparently about 200
| times more likely (1/500000 years) according to wiki, but
| would need to kill 40M people to match the extinction-
| level asteroid risk (so basically-- unmitigated hit on
| Tokyo or bust).
|
| To be honest, I think the 1km diameter range might still
| be a _major_ fraction of the actual risk, because the
| estimates around "human exctinction every 100Ma" are
| probably much too pessimistic.
| ianburrell wrote:
| There is also a difference between mass extinction
| asteroid like dinosaurs, and one that destroys human
| civilization. Smaller one wouldn't extinct humanity but
| would kill most of the people alive. 1km might be big
| enough to do that depending on the amount of dust and
| cooling.
| adgjlsfhk1 wrote:
| they may be worth less, but each class of them bumps up
| the value of detection since detection helps against all
| of them.
| padjo wrote:
| It seems incredibly bizarre to assign a monetary value to
| the elimination of all human life given the concept of
| monetary value would be wiped out along with the people.
| matheusd wrote:
| The counterpoint is that not doing so (implying some sort
| of infinite monetary loss if the entire human species is
| wiped out) would mean you want to spend every single unit
| of monetary value of the entire global economy to
| preventing this (which is also obviously nonsense -
| people have to eat after all).
|
| So you _have_ to put the monetary value somewhere
| (although you 're completely within your right to
| question this _specific_ amount).
| komali2 wrote:
| That's the most interesting application of capitalism-as-
| as-resource-allocation mechanism I've ever seen, that's
| something I look forward to thinking about more.
|
| My immediate reaction though is to doubt the mapping of
| dollar to value - e.g., the 10 million dollar valuation
| of the human life, but also the valuation then of all the
| things that year-dollar-cost could be spent on. Many of
| those things probably don't map very well between true
| value, and dollar cost (my go-to example of this is
| teachers fulfilling one of the most critical roles to
| ensure a functioning society, yet the dollar cost paid
| for their labor being typically far lower than most other
| jobs).
| matheusd wrote:
| You're right to doubt it!
|
| And indeed, accounting for externalities (unmeasured or
| unmeasurable) is a tough economic proposition. If it
| weren't hard to account for every single variable,
| creating a planned economy would be easier (ish).
|
| FWIW, there's a whole sub-field just dedicated to
| determining the value of life for various purposes (a
| starting link:
| https://en.wikipedia.org/wiki/Value_of_life). You may
| disagree with any specific assessment, but then you have
| to argue how that value should be calculated differently.
| padjo wrote:
| I think what I'm trying to express is that it feels like
| the answer isn't any amount of money, it's just
| undefined, like a division by zero or trying to read the
| value of a binary register on a machine that's turned
| off. I think Pirsig called it a Mu answer.
| Joel_Mckay wrote:
| Around 500 tonnes of meteorites hit earth every year.
|
| Tracking large near earth objects is wise for several global
| and domestic security reasons.
|
| Have a great day =3
| boznz wrote:
| Wow, they should have led with this.
| jcims wrote:
| Whoa that's incredible.
|
| (And amazing production of the actual video as well)
|
| Pretty sure you can see some kind of masking for satellites in
| some of the frames of the asteroid videos.
| mrbluecoat wrote:
| And supernovae: https://m.youtube.com/watch?v=Ch18t9cz-
| JU&pp=ygUETHNzdA%3D%3...
|
| Among many other uses:
| https://m.youtube.com/watch?v=h6QYjNjivDE
| KurSix wrote:
| I can't wait to see what it turns up once it's running full
| tilt
| dang wrote:
| Related: https://www.nytimes.com/2025/06/23/science/vera-rubin-
| scient...
|
| (via https://news.ycombinator.com/item?id=44352455, but no
| comments there)
| -warren wrote:
| Counter-rotating spiral galaxies. Super neat!
| https://skyviewer.app/embed?target=186.66721+8.89072&fov=0.2...
| japhyr wrote:
| That is interesting!
|
| They look like they're roughly in the same plane. Is it safe to
| assume they're roughly in the same plane, or could they be
| really distant along the line of sight? The similarity in size
| makes me think they are, but I don't have any reason to be
| confident in that judgment.
| perihelions wrote:
| Those are NGC 4411 a+b and they're indeed right next to each
| other,
|
| https://noirlab.edu/public/images/iotw2421b/ ( _" thought to
| be right next to each other -- both at a distance of about 50
| million light-years"_)
| jcims wrote:
| What's going on directly above with what looks to be 3-4
| galaxies interacting?
| o11c wrote:
| It says that NGC 4410 is (gravitationally) interacting
| galaxies. After clicking through the link, it calls it
| RSCG 55 instead and explains more. I don't understand the
| naming scheme.
| SiempreViernes wrote:
| The naming scheme is based on the principle "tens of
| thousand of people have done this over thousands of
| years, and they all named things themselves". Its not
| uncommon for objects to have ~20 separate names[1], with
| some having over a hundred [2].
|
| In this particular case, RSCG 55 means a group of
| galaxies[3], of which NGC 4410 is one member. Apparently
| RSCG is the "Redshift Survey Compact Groups"
| (https://cds.unistra.fr/cgi-bin/Dic-Simbad?RSCG) so 55 is
| just an index number.
|
| That's also the case for the 4410 after NGC; in that case
| stands for "New General Catalog". In contrast the Sloan
| Digital Sky Survey gave NGC 4410 the name SDSS
| J122628.29+090111.4 where the numbers indicates its
| position in the sky.
|
| The "index number" and the "position of the sky" are the
| two most popular naming strategies.
|
| [1] NGC 4410 has 37, but the NGC objects are among the
| more popular https://simbad.u-strasbg.fr/simbad/sim-
| id?Ident=+NGC+4410&Nb... [2]
| https://simbad.u-strasbg.fr/simbad/sim-
| id?Ident=M87&submit=s... [3]
| https://simbad.u-strasbg.fr/simbad/sim-
| id?Ident=RSCG+55&NbId...
| prawn wrote:
| _" like NGC 4410, above them in this image. The four
| interacting galaxies of that system are connected by
| tidal bridges, created by the gravity of each galaxy
| pulling on the others in the system."_
| jcims wrote:
| Dang. I think I got terminology blinded by the time I got
| there.
| RALaBarge wrote:
| I believe there would be a difference in their red/blue
| signatures if they were moving relative to each other, but as
| you say they clearly are on the same plane
| perihelions wrote:
| > _"?target=186.66721+8.89072 "_
|
| (For those who haven't noticed, you can just simply paste
| 186.66721+8.89072 or whichever target you're curious about in
| an astronomy database like Aladin[0], and there right-click on
| "What is this?")
|
| [0]
| https://aladin.cds.unistra.fr/AladinLite/?target=12%2026%204...
| jcims wrote:
| (Quick side note, if you go to /explorer instead of /embed you
| can zoom out so you can see the whole image at once)
|
| https://skyviewer.app/explorer?target=187.69717+12.33897&fov...
| jlarocco wrote:
| I wonder if there's some kind of gravitational lensing going
| on. A lot of the galaxies look similar, but in different
| orientations.
|
| https://skyviewer.app/embed?target=186.66721+8.89072&fov=0.2...
|
| https://skyviewer.app/embed?target=185.46019+4.48014&fov=0.6...
|
| https://skyviewer.app/embed?target=188.49629+8.40493&fov=1.3...
| ramijames wrote:
| I was surprised by how many lensed objects I could spot.
| kdamica wrote:
| My God, it's full of stars
| trhway wrote:
| brings up that old paradox - should any line of sight
| ultimately end up at a star?
| Jordan-117 wrote:
| https://en.wikipedia.org/wiki/Olbers%27s_paradox
| o11c wrote:
| Note that it makes a _lot_ of assumptions beyond the stated
| ones, such as:
|
| * the only objects in space are stars
|
| * all stars are equally bright
|
| * the average brightness is one that can be seen
|
| (unless you roll all this into "homogeneous"?)
| komali2 wrote:
| Yeah I'm confused because couldn't a black hole between
| us and a star be the reason for a black spot? That times
| a bajillion for whatever else is out there.
| trhway wrote:
| gravitational lensing would make the light go around the
| black hole.
| binarystargazer wrote:
| Image creator here. Now imagine, when the survey is done, we
| will be able to see even fainter objects and image an area of
| the sky 1000x times this size.
| WD-42 wrote:
| The amount of data this thing will be putting out every night is
| insane. For years now the community has been building the
| infrastructure to be able to efficiently consume it for useful
| science, but we still have work to do. Anyone interested in the
| problem of pipelining and distributing 10s of TB of data a night
| should check out the LSST and related GitHubs.
| dekhn wrote:
| I've followed this project for over a decade and the amount of
| data they are moving around is fairly routine, given their
| budget size and access to computing and networking resources.
| The total storage (~40-50PB) is pretty large, but moving 10TB
| around the world isn't special engineering at this point.
| WD-42 wrote:
| It's not about the size of the data in bytes, it's also the
| amount of changes that need to be detected and alerts that
| need to be sent out (estimated at millions a night). Keep in
| mind the downstream consumers of this data are mostly small
| scientific outfits with extremely limited software
| engineering budgets.
| dekhn wrote:
| Again, nothing special. The small outfits aren't going to
| be doing the critical processing.
| WD-42 wrote:
| ...they do the science
| dekhn wrote:
| I've worked on quite a few large-scale scientific
| collaborations like this (and also worked on/talked to
| the lead scientists of LSST) and typically, the end
| groups that do science aren't the ones handling the
| massive infrastructure. That typically goes to well-
| funded sites with great infrastructure who then provide
| straightforward ways for the smaller science groups to
| operate on the bits of data they care about.
|
| Here's the canonical example:
| https://home.cern/science/computing/grid and a lab that
| didn't have enough horsepower using a different grid:
| https://osg-htc.org/spotlights/new-frontiers-at-thyme-
| lab.ht...
|
| Personally, I have pointed the grid folks (I used to work
| on grid) towards cloud, and many projects like this have
| a tier 1 in the cloud. The data lives in S3, metadata in
| some database, and use cloud provider's notification
| system. The scientists work in adjacent AWS accounts that
| have access to those systems and can move data pretty
| quickly.
| WD-42 wrote:
| The difference with this project is the data from Rubin
| itself isn't where most of the scientific value comes
| from. It's from follow up observations. Coordinating
| multiple observatories all with varying degrees of
| programmatic access in order to get timely observations
| is a challenge. But hey if you insist on being an
| "everything is easy" Andy I won't bother anymore.
| Tepix wrote:
| If you're dealing with a fairly constant amount of data
| every day for years, using the cloud will be _way_ more
| expensive than necessary.
| spacecadet wrote:
| The whole thread comes off as an AWS sales pitch...
| dekhn wrote:
| I've setup and built my own machines and clusters, as
| well as setting up grids, and industrial scale
| infrastructure. I've seen many closet clusters, and
| clusters administrated by grad students. Since then, I've
| gone nearly 100% cloud (with a strong preference for
| AWS).
|
| In my experience, there are many tradeoffs using cloud
| but I think when you consider the entire context (people-
| cost-time-productivity) AWS ends up being a very powerful
| way to implement scientific infrastructure. However, in
| consortia like this, it's usually architected in a way
| that people with local infrastructure (campus clusters,
| colo) can contribute- although they tend to be "leaf"
| nodes in processing pipelines, rather than central
| players.
| gregw2 wrote:
| Why move the data? Why not just enable permissions on
| cloud sharing a la Snowflake or iceberg?
| dekhn wrote:
| Sure, that also works, although it often leads to
| problems around cost and scalability and environment
| customization.
| le-mark wrote:
| Is this not the same problem high resolution spy satellites
| have? Seems like a fair bit of crossover at least?
| _alternator_ wrote:
| Spy sats are more bandwidth and power constrained. For low
| earth, you also can't usually offload data over the target.
| NitpickLawyer wrote:
| > For low earth, you also can't usually offload data over
| the target.
|
| That capability is coming with starlink laser modules.
| They've already tested this on a dragon mission, and they
| have the links working between some satellite shells. So
| you'd be able to offload data from pretty much everywhere
| starlink has presence.
| adgjlsfhk1 wrote:
| Vera Ruben is producing ~4gbps constantly. just dealing
| with the heat to send that much data is highly
| nontrivial.
| KurSix wrote:
| Yep, the data engineering side of this is just as fascinating
| as the astronomy
| runako wrote:
| Every set of deep field imagery reminds me that any point of
| light we see could be a star, a galaxy, or a cluster of galaxies.
| The universe is unimaginably vast.
|
| For observatories like Rubin, is there a plan for keeping them
| open after the funding ends? Is it feasible for Chile to take
| over the project and keep it going?
|
| On a practical note, what happens to a facility like this if one
| day it's just locked up? Will it degrade without routine
| maintenance, or will it still be operational in the event someone
| can put together funding?
| prpl wrote:
| It will continue with a new instrument after 10 years
| (spectroscopic) funding permitting. Tololo has been running
| since the 60s. In California, Lick has been running since the
| 1880s.
| runako wrote:
| I get that it will run for a long time as long as someone is
| maintaining it. I am wondering what will happen if the doors
| are locked and the power is cut for an extended period of
| time (5+ years), as seems like a very real possibility unless
| an alternate source of funding can be found.
| prpl wrote:
| That won't happen for this telescope. It has so many unique
| capabilities that other telescopes would be shuttered
| first.
| aragilar wrote:
| There are already facilities like this (obviously not as new as
| Rubin) degrading due to funding, but this is because there's
| usually no better purpose for them. Space monitoring has been
| used in the past as a second life for facilities (outreach
| too), but ~1m class telescopes are good enough now that
| networks of them are better than a 40+ year old telescope. It's
| also worth noting bits can be reused: buildings gutted and
| repurposed, telescopes/instruments moved/sold on, etc.; but the
| real issue is having the staff to look after these places, and
| many older facilities are not always as amenable to automation
| as people might like (especially funding agencies).
|
| Arecibo was about 60 years old for comparison when it
| collapsed, but there are lots of faculties that are effectively
| ships of Theseus, with new instruments coming in over time
| which refresh the faculty (and when that stops happening, then
| you get concerned).
| runako wrote:
| I just skimmed the budget request, and it looks like NSF is
| planning on keeping Vera C. Rubin at least through 2026.
| Really good news!
| w10-1 wrote:
| The zoomed images look grainy as one would expect from raw data,
| but I would have expected them to do dark field subtraction for
| the chips to minimize this effect. Does anyone know if that's
| done (or expressly avoided) in this context, or why it might not
| be as helpful (e.g., for longer exposures)?
| jcims wrote:
| Seems this will be done on the 'nightly' release cadence. Found
| on page 11 in this doc that I found from the wikipedia page:
|
| https://docushare.lsstcorp.org/docushare/dsweb/Get/LSE-163/L...
| binarystargazer wrote:
| Image creator here. We do dark field subtraction, as well as
| many other instrumental calibrations. What you are seeing is
| the fundamental photon noise. Because it is statistical in
| nature, you can never completely eliminate it. We could have
| chosen to put the black point in the image at a much higher
| flux level, but if you go to a high enough signal to noise
| level that you see no grain anywhere, you would miss out on so
| many interesting things that are still quite obvious to make
| out but are only 2-3 sigma above the noise.
| mapt wrote:
| Even one zoom-in and I find something interesting.
|
| What's that faint illuminated tendril extending from M61 (the
| large spiral galaxy at the bottom center of the image) upwards
| towards that red giant? It seems too straight and off-center to
| be an extension of the spiral arm.
|
| EDIT: The supposed "Tidal tail" on M61 was evidently known from
| deep astrophotography, but only rarely detected & commented upon.
| ludsan wrote:
| something green:
| https://skyviewer.app/embed?target=186.82033+8.25479&fov=0.0...
| prpl wrote:
| might be bad cosmic ray rejection during green exposure
| watersb wrote:
| Could be a satellite that moved into the frame during green.
|
| There was a livestream presentation and press conference up on
| YouTube
|
| https://www.youtube.com/live/Zv22_Amsreo?si=zQLeGfJokZoCPkji
|
| At time 1:38:19 - one hour 38 minutes 19 seconds - into the
| livestream presentation, there's a slide that shows RGB streaks
| of fast-moving objects that were removed for the final image.
|
| Those streaks are apparently asteroids.
|
| Perhaps it is indeed a glitch or cosmic ray event.
|
| (Is there a better URL for the slide deck?)
| dogben wrote:
| something red
| https://skyviewer.app/embed?target=186.82033+8.25479&fov=0.0...
| dogben wrote:
| fixed link: https://skyviewer.app/embed?target=187.04483+7.00
| 898&fov=0.2...
| binarystargazer wrote:
| Image creator here. This is such a massive dataset, most of the
| image processing needed to be custom written software
| pipelines. It not really practical for every pixel to be hand
| inspected. A few defects (and bright asteroids) imprinted
| through. It really hard to decide what is a real weird thing in
| the universe, and what is some sort of instrumental effect. We
| try to not pre-decide on what we think we should be seeing and
| filter for those by using things such as using classifiers.
| That leaves us with heuristics based on temporal information,
| size (is it smaller than a point spread function), and other
| related things. On large numbers of objects and pixels 1 in a
| thousand or 1 in a million outliers are bound to occur.
| ludsan wrote:
| I'm glad you responded (i'm assuming you knew i wasn't
| criticizing the effort, but just in case -- I wasn't). I was
| assuming asteroid trail, but I've read that green stars can't
| exist and _could_ be a technosignature of "little green men".
| :) Your work on this is lovely. The combined effort of so
| many smart people over decades of work is truly heartening.
| Thank you.
| botswana99 wrote:
| Jesus H Christ, the Universe is big.
| xoxxala wrote:
| "Space is big. You just won't believe how vastly, hugely, mind-
| bogglingly big it is. I mean, you may think it's a long way
| down the road to the chemist's, but that's just peanuts to
| space." -Douglas Adams
| anjel wrote:
| Sometimes I feel like a diatom floiting in the ocean
| jcims wrote:
| The wikipedia article is quite good -
| https://en.wikipedia.org/wiki/Vera_C._Rubin_Observatory (Edit:
| Treasure trove of details in the references if any of your
| interests are adjacent to this)
|
| The image of the woman holding the model of the sensor is nice
| because it includes a moon for scale.
|
| Question I was curious about is whether or not the focal plane
| was flat (it is).
|
| This is an interesting tidbit:
|
| > _Once images are taken, they are processed according to three
| different timescales, prompt (within 60 seconds), daily, and
| annually._
|
| > _The prompt products are alerts, issued within 60 seconds of
| observation, about objects that have changed brightness or
| position relative to archived images of that sky position.
| Transferring, processing, and differencing such large images
| within 60 seconds (previous methods took hours, on smaller
| images) is a significant software engineering problem by itself.
| This stage of processing will be performed at a classified
| government facility so events that would reveal secret assets can
| be edited out._
|
| They are estimating 10 million alerts per night, which will be
| released publicly after the previously mentioned assessment takes
| place.
| robotnikman wrote:
| >The prompt products are alerts, issued within 60 seconds of
| observation, about objects that have changed brightness or
| position relative to archived images of that sky position.
| Transferring, processing, and differencing such large images
| within 60 seconds (previous methods took hours, on smaller
| images) is a significant software engineering problem by
| itself.[64]
|
| >This stage of processing will be performed at a classified
| government facility so events that would reveal secret assets
| can be edited out.
|
| Interesting, I'm guessing secret spy satellites?
| kkylin wrote:
| "Let's look for spy satellites / orbiters" was an
| "application" I wondered about. My second thought about this
| was: maybe the US (and possibly other countries) already have
| something like this, but classified?
| dekhn wrote:
| The US already has a very sophisticated system for this.
|
| https://en.wikipedia.org/wiki/United_States_Space_Surveilla
| n...
| adgjlsfhk1 wrote:
| note that lots of the lsst funding is from the DOE. part of
| the value for the government might be tracking Chinese
| satellites
| ianburrell wrote:
| There is the Space Surveillance Telescope [1] in Australia.
| It is similar military telescope for space tracking. It is
| only 3.5m compared to LSST 8m.
|
| 1:
| https://en.wikipedia.org/wiki/Space_Surveillance_Telescope
| realo wrote:
| .. and aliens, of course ...
| gmueckl wrote:
| I expect a lot of events to get filtered that foreign
| governments expect to stay reasonably secret, even if they
| aren't friendly with the US. It's a game.
|
| The thing that really saddens me is that the military gets to
| filter the data first and scientists only get to see the
| already manipulated data instead of a raw feed from their own
| instrument.
| prpl wrote:
| it's spy satellites (mainly domestic). In some cases, they
| don't actually need to be removed, just embargoed until
| orbital change.
| BurningFrog wrote:
| I thought all satellites already have known orbits?
|
| Both because they can't be made invisible, and because you
| need to avoid collisions.
| Xss3 wrote:
| Many can (and do) change orbits.
| royal__ wrote:
| "Space is big. You just won't believe how vastly, hugely, mind-
| bogglingly big it is. I mean, you may think it's a long way down
| the road to the chemist's, but that's just peanuts to space."
| mjsweet wrote:
| Back in January 2010 I went on a blind date with a lady who's now
| my wife -- an astrophysicist. We talked about this instrument and
| how Google would shuffle petabytes of raw observations, then
| distilling them into datasets researchers could actually use
| (don't know if Google is still involved?). We'll celebrate 15
| years of marriage this January, and I have been following the
| progress of this telescope since 2007 or so. It's amazing how
| long it takes for these instruments to come online, but the
| benefits are significant.
| jcims wrote:
| > We'll celebrate 15 years of marriage this January,
|
| Congrats!
| throw0101c wrote:
| PetaPixel has a decent article / video on the topic from a visit
| to the observatory:
|
| * https://petapixel.com/2025/06/23/hands-on-at-the-vera-c-rubi...
|
| Not _super_ technical, but a little higher level (with decent
| analogies to photography, for their traditional audience).
| adgjlsfhk1 wrote:
| I really like that they mentioned how the telescope will be
| sub-optimal for wedding photography
| Helmut10001 wrote:
| Check out this video:
| https://rubinobservatory.org/gallery/collections/first-look-...
|
| Incredible.
| 0x0203 wrote:
| For anyone that hasn't clicked the link, it shows that in just
| a few days, the observatory has already found over 2000 new
| asteroids. That is indeed very impressive.
| KurSix wrote:
| Imagine what it'll be turning up once the full survey is
| underway
| nvk255 wrote:
| For a step by step tour: https://skyviewer.app/tours/cosmic-
| treasure-chest/
| keyle wrote:
| Petition to name those two mirrored galaxies "Wax on" and "wax
| off"?
|
| I'll see myself out.
| burstoflight wrote:
| Took me a while but I got it
| gattr wrote:
| Related: _When a Telescope Is a National-Security Risk_ [1];
|
| TL;DR: VCRO is capable of imaging spy- and other classified US
| satellites. An automated filtering system (involves routing
| through some government processing facility) is in place to
| remove them from the freshly captured raw data used for the
| public transient phenomena alert service. 3 days later,
| unredacted data is made available (by then the elusive, variable-
| orbit assets are long gone.)
|
| [1] https://www.theatlantic.com/science/archive/2024/12/vera-
| rub...
| funkypants wrote:
| What is this?
| https://skyviewer.app/embed?target=183.65537+6.09434&fov=0.0...
| spacecadet wrote:
| Looks like two galaxies interacting/merging.
| 0x0203 wrote:
| Why do the brighter objects have the four way cross artifact? My
| (apparently incorrect) understanding was that those types of
| artifacts were a result of support structures holding reflecting
| mirrors on a telescope. But this camera just has a "standard"
| glass lense with nothing obstructing the light path to the
| sensor.
| frontfor wrote:
| It's a reflecting telescope, not a camera with a glass lens.
| 0x0203 wrote:
| Ah, thanks. I had seen a bunch of hype about the camera
| itself (which is on its own very impressive) and assumed that
| was the complete device. Didn't realize it was part of a
| larger telescope.
| binarystargazer wrote:
| You are not wholly wrong! There is both a supporting structure
| for the mirror, AND a glass lens in front of the sensor to
| further flatten the incoming light.
|
| The interesting thing about the spikes in our images is that
| they stay fixed in image plane coordinates, not sky
| coordinates. So as the night sky moves (earth rotates) the
| spikes rotate relative to the sky leading to a star burst
| pattern over multiple exposures.
| ethan_smith wrote:
| Those diffraction spikes are caused by the four-vane spider
| structure supporting the secondary mirror in the telescope's
| optical path, not by the camera lenses themselves.
| KurSix wrote:
| The potential for discoveries here seems enormous
| binarystargazer wrote:
| I'm the Rubin team member responsible for mapping the data into
| RGB images. I have been a long time reader of hacker news, but
| finally made an account to comment on this. I wanted to thank
| everyone here for their interest and taking their time to check
| out these images. Seeing everyone interested and engaged makes
| all the long hours worth it.
| phkahler wrote:
| What range of wavelengths are in the original images? Do you
| produce multiple RGB images for looking at different things?
| c'mon, what does that entail? ;-)
| binarystargazer wrote:
| The filters used for this range from near infrared to near
| uv. We used 4 different filters in all (for this image, the
| telescope has more). In general yes to fully appreciate all
| the color information as a human we need to generate
| different color combos so our eyes can pick up different
| contrasts.
|
| However, what we strive for is being accurate to "if your
| eyes COULD see like this, it would look like this". To the
| best our our ability of course. We did a lot of research into
| human perception to create this and tired to map the
| information of color and intensity in a similar way to how
| your brain constructs that information into an image.
|
| Let me tell you, I did not appreciate how deep a topic this
| was before starting, and how limited our file formats and
| electronic reproduction capabilities are for this. The data
| has such a range of information (in color and intensity) it
| is hard to encode into existing formats that most people are
| able to display. I really want to spend some time to do this
| in modern HDR (true HDR, not tone-mapping) where the
| brightness can actually be encoded separately than just RGB
| values. The documentation on these (several competing)
| formats is a bit all over the place though.
|
| Edit: I wanted to edit to add, if anyone reading this is an
| expert in HDR formats and or processing, I'd live to pick
| your brain a bit!
| feoren wrote:
| I'm impressed so much thought went into how to colorize the
| image! Sometimes it seems like space photos are just
| colorized thoughtlessly, or to increase the "wow" factor,
| so it's great to hear how careful and thoughtful you guys
| were in mapping this data to color-space.
| legohead wrote:
| Thank you for your work!
| matiascoin wrote:
| Amazing
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