CWISEP J193518.59-154620.3: An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered with CatWISE

Author(s): Marocco, F; Caselden, D; Meisner, AM; Kirkpatrick, JD; Wright, EL; Faherty, JK; Gelino, CR; Eisenhardt, PRM; Fowler, JW; Cushing, MC; Cutri, RM; Garcia, N; Jarrett, TH; Koontz, R; Mainzer, A; Marchese, EJ; Mobasher, B; Schlegel, DJ; Stern, D; Teplitz, HI | Abstract: © 2019. The American Astronomical Society. All rights reserved. We present the discovery of an extremely cold, nearby brown dwarf in the solar neighborhood, found in the CatWISE catalog. Photometric follow-up with Spitzer reveals that the object, CWISEP J193518.59-154620.3, has ch1-ch2 = 3.24 ±0.31 mag, making it one of the reddest brown dwarfs known. Using the Spitzer photometry and the polynomial relations from Kirkpatrick et al. we estimate an effective temperature in the ∼270-360 K range, and a distance estimate in the 5.6-10.9 pc range. We combined the WISE, NEOWISE, and Spitzer data to measure a proper motion of mas yr-1, μ δ = -50 ±97 mas yr-1, which implies a relatively low tangential velocity in the range 7-22 km s-1.