WISE J064336.71-022315.4: A Thick Disk L8 Gaia DR2-Discovered Brown Dwarf at 13.9 Parsecs. (arXiv:1811.03477v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Mamajek_E/0/1/0/all/0/1">E. E. Mamajek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marocco_F/0/1/0/all/0/1">F. Marocco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rees_J/0/1/0/all/0/1">J. M. Rees</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smart_R/0/1/0/all/0/1">R. L. Smart</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cooper_W/0/1/0/all/0/1">W. J. Cooper</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burgasser_A/0/1/0/all/0/1">A. J. Burgasser</a>

While spectroscopically characterizing nearby ultracool dwarfs discovered in
the Gaia Second Data Release with the TripleSpec spectrograph on the Palomar
200” telescope, we encountered a particularly cool, nearby, new member of the
solar neighborhood: Gaia DR2 3106548406384807680 = WISE J064336.71-022315.4 =
2MASS J06433670-0223130. The $it{Gaia}$ parallax corresponds to a distance of
13.9 $pm$ 0.3 pc. Using our TripleSpec spectrum we classify W0643 as spectral
type L8, and measured a heliocentric radial velocity of 142 $pm$ 12 km
s$^{-1}$. When combined with $it{Gaia}$ astrometry, we determine a Galactic
velocity (heliocentric; $U$ towards Galactic center) of $U, V, W$ = -109, -91,
-12 ($pm$10, 5, 3) km s$^{-1}$. We estimate that W0643 passed within $sim$1.4
pc away from the Sun $sim$100,000 years ago.

While spectroscopically characterizing nearby ultracool dwarfs discovered in
the Gaia Second Data Release with the TripleSpec spectrograph on the Palomar
200” telescope, we encountered a particularly cool, nearby, new member of the
solar neighborhood: Gaia DR2 3106548406384807680 = WISE J064336.71-022315.4 =
2MASS J06433670-0223130. The $it{Gaia}$ parallax corresponds to a distance of
13.9 $pm$ 0.3 pc. Using our TripleSpec spectrum we classify W0643 as spectral
type L8, and measured a heliocentric radial velocity of 142 $pm$ 12 km
s$^{-1}$. When combined with $it{Gaia}$ astrometry, we determine a Galactic
velocity (heliocentric; $U$ towards Galactic center) of $U, V, W$ = -109, -91,
-12 ($pm$10, 5, 3) km s$^{-1}$. We estimate that W0643 passed within $sim$1.4
pc away from the Sun $sim$100,000 years ago.

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