Coincidence No 1

the bright centre of this hazy blob is marked as a star in SDSS spectroscopy…

As I suspected it’s a nucleated dwarf (elliptical) galaxy, SDSS automated spectro classification has had great difficulty with a lot more of those.

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Nucleated dwarf, or regular elliptical with an AGN?

I saw 1 or more dwarf references in SIMBAD / NED, also I collected them in GZ so by shape tend to recognize them. And If I remember correctly its very common for SDSS to classify the core of those as star too.

To be sure you’d have to find the est. size in NED or guestimate, no time now I’m on. Voorwerpje rush :slight_smile:

Uh, yeah, I don’t think it’s something you can tell for sure just by looking at shape.

Ofcourse not for sure, but I guessed it was a nucleated dwarf and that turned out to be correct through SIMBAD, so a good guesstimate is definitely possible.

Take a look at my collection and see how similar they all are;

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Here is the original SDSS image of this object

Yes, they all look kind of faint. It would be very interesting to me to see if there are larger, more distant elliptical galaxies that look similar to nearer, fainter dwarf galaxies. This was always one of those things I felt I could never make assumptions on, but perhaps there is something about galaxy morphology that causes a distinct cutoff in appearance between dwarf and larger galaxies.

At least for nucleated dwarfs I think it’s possible, with that weak point source in the center. For other types of dwarfs I suspect it might be a lot more difficult, but interesting indeed.

GAIA gives paralax 1 for this source. Why is that if it is galaxy center?

My guess is that it’s 1 ± 1, so actually consistent with zero. I should have added the errors to the Gaia data popup!
You could try looking up this object (by RA,Dec) in the Gaia Archive (


Thank you! This was my suspection too. Clearly it looks like a galactic center source :slight_smile: