Overlappng or merging?
-
by suelaine
Are these almost identical ellipses merging or overlapping? I believe that the bright object below the bottom galaxy is a star. If there was an overlap then in a few million years there might be an eclipse.
Posted
-
by JeanTate in response to suelaine's comment.
Yes, the bright white object - which is, in fact in the center (and which the SDSS photometric pipeline thinks is a galaxy!), and so is what we're supposed to classify - is a star.
The two yellowish galaxies are 'ETGs', 'early-type galaxies', informally called 'ellipticals'. As ETGs are, for the most part, devoid of gas and dust, and as they often do not have disks, it's much harder to tell - just from eyeballing them - whether two like this are merging or simply overlapping ... no obvious distortions, no 'tidal tails', no weird dust lanes ... I think it might be possible to tell if they're merging or overlapping if they were observed with a super-advanced instrument on a big telescope, but until then ...
Posted
-
by suelaine
Thanks Jean Tate….. suelaine
Posted
-
by JeanTate in response to JeanTate's comment.
You're welcome suelaine.
Yes, the bright white object - which is, in fact in the center (and which the SDSS photometric pipeline thinks is a galaxy!), and so is what we're supposed to classify - is a star.
Actually, as an eagle-eyed zooite pointed out to me (via a PM), what's in the center (in this case) is the middle yellow blob - an ETG! 😦 (thank you, my fellow zooite).
The white star was served up to be classified, but it's AGZ0003lig (discussion on it here), not AGZ0003lie. Will likely be a real headache for the Science Team to merge the classifications!
Posted
-
by suelaine
OK,if the bright white object at the bottom is a galaxy, then is it an AGN?
Posted
-
by JeanTate in response to suelaine's comment.
But it isn't; it's an ordinary star, in our own galaxy (the automatic SDSS photometric pipeline made a mistake).
Posted