Lens or galaxy?

https://www.legacysurvey.org//viewer/?ra=118.6264&dec=13.1715&layer=ls-dr9&zoom=16&sga-parent&sga&const

SDSS keeps referring to the bright star North to the object:

Possible lens or galaxy

If you turn on the Gaia EDR3 layer (under “imaging catalogs”), you will see that the blue object here is a star with measurable proper motion.

1 Like

indeed, but the streak just South to that star returns no hit.

It’s too faint to be detected in SDSS. The Legacy Surveys measure considerably deeper than SDSS. To me it looks like a regular faint galaxy.

cheers,
–dustin

1 Like

I think what Dustin was getting at is that the streak can’t be lensing around a star.

That said, the edr3 proper motion and parallax are so low (and within error of 0) that it could actually be a quasar.

Proper motions are -1.3 ± 0.1 and -2.0 ± 0.1 – extremely significant. Parallax is only 0.1 ± 0.2 – consistent with zero.

ie it’s definitely moving. So a star.

Thank you, gentlemen!

Very interesting additions, I still have to learn how to look up these numbers and wrap my head around those.

What about this one: 07 43 42.788 +13 02 43.77
https://www.legacysurvey.org/viewer/exposures/?ra=115.9284&dec=13.0452&layer=ls-dr9

Lol i’m so used to dealing with BDs that often move at hundreds of mas/yr that I always forget about the slow stuff :wink: I guess at such a distance, those pms could make it pretty fast.

RUWE looks pretty normal so I dont doubt the astrometry.

Typical galaxy. In LS DR9 we actually incorrectly split it into two galaxies.

1 Like