Back to Volume
Paper: Spitzer Mid-Infrared Photometry of 500 – 750 K Brown Dwarfs
Volume: 448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun
Page: 913
Authors: Leggett, S. K.; Albert, L.; Artigau, E.; Burningham, B.; Delfosse, X.; Delorme, P.; Forveille, T.; Lucas, P. W.; Marley, M. S.; Pinfield, D. J.; Reylé, C.; Saumon, D.; Smart, R. L.; Warren, S. J.
Abstract: Mid-infrared data, including Spitzer warm-IRAC [3.6] and [4.5] photometry, is critical for understanding the cold population of brown dwarfs now being found, objects which have more in common with planets than stars. As effective temperature (Teff) drops from 800 K to 400 K, the fraction of flux emitted beyond 3μm increases rapidly, from about 40% to >75%. This rapid increase makes a color like H-[4.5] a very sensitive temperature indicator, and it can be combined with a gravity- and metallicity-sensitive color like H–K to constrain all three of these fundamental properties, which in turn gives us mass and age for these slowly cooling objects. Determination of mid-infrared color trends also allows better exploitation of the WISE mission by the community. We use new Spitzer Cycle 6 IRAC photometry, together with published data, to present trends of color with type for L0 to T10 dwarfs. We also use the atmospheric and evolutionary models of Saumon & Marley to investigate the masses and ages of 13 very late-type T dwarfs, which have H-[4.5]>3.2 and Teff ≈500 K to 750 K. Note: This is an updated version of Leggett et al. (2010a); a photometry compilation is available at
Back to Volume