SDSS J1632$+$3505: A Possible Brown Dwarf Companion to a Nearby Main-Sequence Star

POSTER

Abstract

Brown dwarf companions to stars are valuable to the advancement of brown dwarf knowledge. These sources are advantageous finds because fundamental properties, such as mass and age, are difficult to measure for brown dwarfs, but can be obtained for their main sequence primaries. We have identified a brown dwarf, SDSS J1632$+$3505, as a likely companion to the sun-like star HD 149361. We propose that this pair is gravitationally bound by determining similar distances (29$+$/-5 pc for brown dwarf; 36$+$/-6 pc for star) and similar proper motions. We classify the near-infrared spectrum of SDSS J1632$+$3505 as an L1 dwarf with a temperature of 1900$+$/-200 K. We also find a rough age estimate of 400$+$/-200 Myr. Using high-resolution optical spectroscopy, we classify HD 149361 as K0 $+$/- 2 subtypes, with a temperature of 5250$+$/-350 K. Using lithium abundance relations, we estimate an age around 300$+$/-200 Myr. The consistency between the distances, proper motions, and ages confirm coevality although chromospheric activity may be used as an age indicator to further constrain the age of the star and declare this system a useful benchmark for testing atmosphere models of cool stars, brown dwarfs, and extrasolar planets.

Authors

  • Gretel Mercado

    Univ of California - San Diego

  • Chi-Yu Hu

    University of California - Berkeley, National Institute for Materials Science, Caifornia State University, Long Beach, University of Michigan, Stockholm University, California State University, Long Beach, Utrecht University, Carl von Ossietzky University of Oldenburg, Germany, Hartnell Community College, Department of Physics, Stockholm University, GRAPPA, University of Amsterdam, Paul Scherrer Institute, Switzerland, California State University, Fresno, California State University Long Beach, Cal State Univ- Long Beach, University of Nevada, Reno, University of Rogensberg, Germany, Tribhuvan University, Nepal, University of Victoria and Perimeter Institute for Theoretical Physics, Institute of Physics, Jagiellonian University, Helmholtz Institute Mainz, Johannes Gutenberg University, Physics Department of the University of Nevada, Reno, Universita del Sannio, Cal Tech, California State University, Los Angeles, Univ of California - San Diego, UC Berkeley, Lawrence Livermore National Laboratory, Department of Physics & Astronomy, University of California, Irvine 92617, Department of Chemistry and of Physics & Astronomy, University of California, Irvine 92617, SLAC National Laboratory, Humboldt State University, Physics Department, University of Nevada, Reno, Univ of California - Merced

  • Chi-Yu Hu

    University of California - Berkeley, National Institute for Materials Science, Caifornia State University, Long Beach, University of Michigan, Stockholm University, California State University, Long Beach, Utrecht University, Carl von Ossietzky University of Oldenburg, Germany, Hartnell Community College, Department of Physics, Stockholm University, GRAPPA, University of Amsterdam, Paul Scherrer Institute, Switzerland, California State University, Fresno, California State University Long Beach, Cal State Univ- Long Beach, University of Nevada, Reno, University of Rogensberg, Germany, Tribhuvan University, Nepal, University of Victoria and Perimeter Institute for Theoretical Physics, Institute of Physics, Jagiellonian University, Helmholtz Institute Mainz, Johannes Gutenberg University, Physics Department of the University of Nevada, Reno, Universita del Sannio, Cal Tech, California State University, Los Angeles, Univ of California - San Diego, UC Berkeley, Lawrence Livermore National Laboratory, Department of Physics & Astronomy, University of California, Irvine 92617, Department of Chemistry and of Physics & Astronomy, University of California, Irvine 92617, SLAC National Laboratory, Humboldt State University, Physics Department, University of Nevada, Reno, Univ of California - Merced