CWISEP J1935─1546: An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered - PowerPoint Presentation

1. CWISEP J1935─1546: An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered with CatWISEFederico Marocco (NPP Fellow)Science Question: How can star formation create stars of extremely low mass, down to a few times the mass of Jupiter (~0.001 solar masses)? And with what efficiency? Is there a low-mass cutoff to star formation? These are important questions with broad astrophysical impact.Data and Results: The NASA mission Wide-field Infrared Survey Explorer (WISE) has been scanning the sky in the mid-IR since 2010. The ADAP-funded project CatWISE has combined all of WISE data from the 2010-2016 phases of the mission to generate an all-sky catalog of photometry and proper motion, measured to a precision 10x better than the previous AllWISE catalog data. The preliminary CatWISE catalog was released in August 2019 via IRSA.Significance: CWISEP J1935-1546 is the coldest among the brown dwarfs so far discovered using CatWISE. These objects are crucial to understand the formation process of the lowest mass stars.Marocco, et al. 2019, ApJ, 881, 17, DOI:10.3847/1538-4357/ab2bf0CatWISE is funded by NASA Proposal No. 16-ADAP16-00ch1-ch2 is the magnitude difference of the observations with the Spitzer ch1 and ch2 filter passbands. Each black point is a known cold brown dwarf. The blue solid line a polynomial fit (Kirkpatrick et al., 2019, ApJS). The color measured using Spitzer for CWISEP J1935-1546 places it squarely between the coldest known brown dwarf, WISE 0855 (point in the bottom right corner), and the other stars. By populating the existing gap we can build a statistically significant sample to constrain the low-mass end of the initial mass function. National Aeronautics and Space AdministrationJet Propulsion LaboratoryCalifornia Institute of Technology

2. National Aeronautics and Space AdministrationJet Propulsion LaboratoryCalifornia Institute of TechnologyContact: Federico MaroccoMail stop 169-237Jet Propulsion Laboratory, Pasadena, CA 91109frederico.marocco@jpl.nasa.govCitation: Marocco, et al., CWISEP J193518.59–154620.3: An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered with CatWISE, ApJ, 881, 17, 2019, DOI: 10.3847/1538-4357/ab2bf0Data Sources:The NASA WISE mission Technical Description of Figure:Teff (vertical axis) as a function of Spitzer ch1–ch2 colors (horizontal axis) for nearby late T and Y dwarfs. ch1-ch2 is the magnitude difference of the observations with the Spitzer ch1 and ch2 filter passbands. Black points are known cold dwarfs taken from Kirkpatrick et al. (2019, Table 8). The red dashed lines encompass the 1σ color range for CWISEP J1935–1546. Overplotted in blue is the polynomial relation presented in Kirkpatrick, J. D., Martin, E. C., Smart, R. L., et al. 2019, ApJS, 240, 19. The color measured using Spitzer for CWISEP J1935-1546 places it squarely between the coldest known brown dwarf, WISE 0855 (the point in the bottom right corner), and the rest of the sample. By populating the existing gap we can build a statistically significant sample to constrain the low-mass end of the initial mass function.Scientific significance, societal relevance, and relationships to future missions:CWISEP J1935-1546 is the coldest among the brown dwarfs so far discovered using CatWISE. These objects are crucial to understand the formation process of the lowest mass stars. .