Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Vera C. Rubin Observatory first images

rubinobservatory.org

Post reply on HN
Print view View original

81–90 of 172 posts

Re: Vera C. Rubin Observatory first images

#81

Post by prpl »

runako wrote: post #32

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…

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.

Re: Vera C. Rubin Observatory first images

#83

Post by o11c »

jcims wrote: post #42
perihelions wrote: post #23

Earlier quoted context omitted.

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" )

What's going on directly above with what looks to be 3-4 galaxies interacting?

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.

Re: Vera C. Rubin Observatory first images

#84

Post by o11c »

Jordan-117 wrote: post #69
trhway wrote: post #26

Earlier quoted context omitted.

brings up that old paradox - should any line of sight ultimately end up at a star?

https://en.wikipedia.org/wiki/Olbers%27s_paradox

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"?)

Re: Vera C. Rubin Observatory first images

#85

Post by erikerikson »

sdafi239 wrote: post #60
perihelions wrote: post #31

Earlier quoted context omitted.

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-...

nice

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.

Re: Vera C. Rubin Observatory first images

#86

Post by Joel_Mckay »

m3kw9 wrote: post #33
krunck wrote: post #9

The asteroid detection capability is amazing: https://rubinobservatory.org/news/rubin-first-look/swarm-ast...

Which also tells the astronomical low odds of asteroids hitting earth even with “so many” of them. To me it changes nothing

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

Re: Vera C. Rubin Observatory first images

#87

Post by grues-dinner »

dekhn wrote: post #8

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…

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.

Re: Vera C. Rubin Observatory first images

#88

Post by nullc »

perihelions wrote: post #7
NitpickLawyer wrote: post #5

Earlier quoted context omitted.

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).

> "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…

> 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..

Re: Vera C. Rubin Observatory first images

#89

Post by NitpickLawyer »

_alternator_ wrote: post #67
le-mark wrote: post #57

Earlier quoted context omitted.

Is this not the same problem high resolution spy satellites have? Seems like a fair bit of crossover at least?

Spy sats are more bandwidth and power constrained. For low earth, you also can’t usually offload data over the target.

> 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.

Post reply on HN