Possible brown dwarf or asteroid?

Interesting things
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https://www.legacysurvey.org//viewer/?ra=208.2813&dec=5.1524&layer=ls-dr10&zoom=16

I thought it was an asteroid, but a quick trip to SIMBAD revealed it was Gaia DR3 3719989926617172480, a nearby High Proper Motion Star. Other than being in Stellar and substellar companions from Gaia EDR3 (Kervella+, 2022), there is little known about it. It has no known spectral type, and it was classified as its own parent object.

Gaia DR3 stats:
Plx: 19.0846
pmRA: -186.128 mas/yr
pmDE: 142.827 mas/yr
Gmag:~ 20G
Temperature estimate from RP: 2260.31K

Could this be a brown dwarf?

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On the wikipedia page, a temp of 2260 K would put it around the M-dwarf / red dwarf to L-dwarf / brown dwarf boundary.

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Nice, I hope that that Gaia’s temperature estimates are accurate.
I also found that was in Gaia’s catalog for ultracool dwarfs. They estimated that the radius was about 0.108499750 solar radii with an uncertainty of 0.0111913000. If I add the uncertainty, it would be a bit too large, but without it, it would be the size of a large brown dwarf.

Here’s the catalog:VizieR

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I’ve never really trusted the gaia photometry-derived Teffs. Ultimately with M/L transition objects like this, you really need a spectrum to know which side of the transition it lies on.

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Worth noting that if its field age, its not really a brown dwarf unless its ~L2-L3.