Interesting Object

https://www.legacysurvey.org//viewer/?ra=137.9838&dec=27.8995&layer=ls-dr9&zoom=14

if you mean that blue thing at 4 o’clock, I think that’s an artifact (not sure what kind! un-flagged) in one of the g-band exposures.

How do you tell the difference between an artifact and something transient? (I found this by flipping through radio signatures of a catalogue of galaxies we have and seeing if there was anything interesting on the mark.) So I didn’t find this through a visual search either, it first came from the small blip in the radio. And look, it looks small, that radio signature, but I’ve flipped through 250 galaxies marking their radio signatures) and so it was “flagged” in my book. “Faint radio…” and then I see this and it looks like the teardrop is angled through that ring. Now, again, not a hill I’ll die on. But the DR8 images show it too! Were they taken differently from the DR9 images or single exposures? Ugh

So how do you tell the difference between an artifact and a transient, Look obviously I’m doing something wrong, if you guys can find cool stuff, but I only find artifacts.

Doesn’t show up
2018-03-16 - G band

Shows up
2018-12-10 G band

If it is less likely that an astrophysical jet have reached that area, blasted a whole through dust, and illuminated that between those nine months, than an artifact, cool. Well Id like to know why or is there another telescope that has looked at that area in the visual spectrum with sufficient resolution?

I’m looking at the individual exposures here,
https://www.legacysurvey.org/viewer/exposures/?ra=137.9827&dec=27.8989&layer=ls-dr9
you can see it’s only in that one g exposure. And it looks super weird. I don’t know what it is – it looks circular! Anything that came through the telescope optics (not cosmic rays) would be blurred out and round, but this has sharp edges, so I don’t think it can be an astrophysical object.

Well, you are the point spread artisan… it does sort of look like when a meteor is removed. But then again it also reminds me of the orginal hanny’s… but that gas in the orignal hanny’s was 81 million light years away :wink:

Well okay, so you’re saying its a neutrino? (just kidding :wink:

image

Yes, well if you zoom in you can notice a crosshair is there is something to do with point spread?

If it was a voorwerp, it would appear in more than a single exposure. Its definitely an artifact. It reminds me of a cosmic ray hit, but circular would be an odd presentation. Improperly subtracted asteroid is possible, I guess.

I just said asteroid since Dustin helped me out with that as one of my first questions which was: what was one of those red carina nebula looking remnant thing looking artifacts and others helped show it was a removed asteroid. But okay great guys. So that blue disk-ring is an artifact, of magical and ancient power, as all artifacts we carry. :wink:

I’m reading the signs and maybe I should redirect my focus to artifice, not astronomy, astronomy far too much math and constraint, and ascii files, now artifice… well you can’t spell that without art. Actually one of the reasons I like this forum and you guys is there is something beautiful about pure exploration. But yeah so I’m hearing you a voorwerp would be impossible to view transiently in our cosmically small lifetimes. But we can see the aftermath of the synchotron cannon through the circumstellar and then interstellar mediums, by looking at the thousands of lightyears long gas that they excited long ago.

However, I am still confused as to why we can see supernova over seemingly large spatial distances, transiently, if we have to wait for the speed of light. Like don’t supernova appear larger than their progenitor star (radius), sorry for the question … I understand when a light brightens we can see it because of the increase in luminosity and apparent luminosity, but I don’t understand the size of the circles of supernova away in the distance. Could someone explain to me how they get to look that large?