Improved infrared photometry and a preliminary parallax measurement for the extremely cold brown dwarf CWISEP J144606.62-231717.8

We present follow-upSpitzerobservations at 3.6μm (ch1) and 4.5μm (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) data via the CatWISE Preliminary Catalog by Meisner et al. (2019b), where an initial Spitzer color of ch1–ch2 = 3.71±0.44 mag was reported. Additional Spitzer data presented here allows us to revise its color to ch1–ch2 = 2.986±0.048 mag, which makes CWISEP J144606.62–231717.8 one of the reddest brown dwarfs 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+1.7−1.3pc.