Bibcode
Troup, N. W.; De Lee, Nathan M.; Carlberg, Joleen K.; Nidever, David L.; Majewski, Steven R.; Stassun, Keivan; Covey, Kevin R.; Skrutskie, Michael F.; Allende-Prieto, C.; Hearty, Fred R.; APOGEE Substellar Companions Working Group
Bibliographical reference
American Astronomical Society, AAS Meeting #227, id.#142.13
Advertised on:
1
2016
Citations
0
Refereed citations
0
Description
While both exoplanets and stellar-mass companions have been found in
extremely short-period orbits, there has been a paucity of brown dwarf
(BD) companions orbiting Sun-like stars, a phenomenon known as the
"Brown Dwarf Desert." However, more recent work has shown that this
Desert might be limited in extent, only existing for small separation (a
< 5-10 AU) companions, and may not be as "dry" as initially thought.
It has been previously suggested that there may be an "F Dwarf Oasis,"
where the BD Desert observed for Solar-like stars ceases to exist for F
dwarf stars. The Sloan Digital Sky Survey (SDSS-III) Apache Point
Galactic Evolution Experiment (APOGEE) has compiled a catalog of ~400 of
its most compelling stellar and substellar companion candidates orbiting
host stars of various spectral types and evolutionary states. Among
these candidates, approximately 100 had a derived companion mass in the
BD regime (13-80 MJup), which is a significant increase
compared to the number of known small separation (a < 1 AU) BD
companions. Our sample appears to manifest the BD desert, but only for
seperations < 0.2 AU rather than the previously held 5 AU. This is
explained by one of the unique qualities of our sample when compared to
previous companions surveys: Two-thirds of the BD candidates in our
sample are orbiting evolved stars, most of which were F dwarfs during
their main sequence lifetime, consistent with the notion of an F Dwarf
Oasis. Using this sample, we further test this hypothesis by
constraining the formation mechanisms of BD companions, and exploring
their orbital evolution as their host evolves off the main sequence.