Improved infrared photometry and a preliminary parallax measurement for
  the extremely cold brown dwarf CWISEP J144606.62$-$231717.8
  We present follow-up $Spitzer$ observations at 3.6$\mu$m (ch1) and 4.5$\mu$m
(ch2) of CWISEP J144606.62$-$231717.8, one of the coldest known brown dwarfs in
the solar neighborhood. This object was found by mining the Wide-field Infrared
Survey Explorer ($WISE$) and $NEOWISE$ data via the CatWISE Preliminary Catalog
by Meisner et al. (2019b), where an initial $Spitzer$ color of ch1$-$ch2 =
3.71$\pm$0.44 mag was reported, implying it could be one of the reddest, and
hence coldest, known brown dwarfs. Additional $Spitzer$ data presented here
allows us to revise its color to ch1$-$ch2 = 2.986$\pm$0.048 mag, which makes
CWISEP J144606.62$-$231717.8 the 5th reddest brown dwarf ever observed. A
preliminary trigonometric parallax measurement, based on a combination of
$WISE$ and $Spitzer$ astrometry, places this object at a distance of
10.1$^{+1.7}_{-1.3}$ pc. Based on our improved $Spitzer$ color and preliminary
parallax, CWISEP J144606.62$-$231717.8 has a $T_{\rm eff}$ in the 310$-$360 K
range. Assuming an age of 0.5$-$13 Gyr, this corresponds to a mass between 2
and 20 $M_{\rm Jup}$.
