Saved in:
Bibliographic Details
Main Authors: Whitebook, Samuel, Brandt, Timothy, Brandt, Gregory Mirek, Martin, Emily
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2410.11999
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910652146122752
author Whitebook, Samuel
Brandt, Timothy
Brandt, Gregory Mirek
Martin, Emily
author_facet Whitebook, Samuel
Brandt, Timothy
Brandt, Gregory Mirek
Martin, Emily
contents We present two epochs of radial velocities of the first imaged T dwarf Gliese 229B obtained with Keck/NIRSPEC. The two radial velocities are discrepant with one another, and with the radial velocity of the host star, at $\approx$$11σ$ significance. This points to the existence of a previously postulated, but as-yet undetected, massive companion to Gl 229B; we denote the two components as Gl 229Ba and Gl 229Bb. We compute the joint likelihood of the radial velocities to constrain the period and mass of the secondary companion. Our radial velocities are consistent with an orbital period between a few days and $\approx$60 days, and a secondary mass of at least $\approx$15\,$M_{\rm Jup}$ and up to nearly half the total system mass of Gl 229B. With a significant fraction of the system mass in a faint companion, the strong tension between Gl 229B's dynamical mass and the predictions of evolutionary models is resolved.
format Preprint
id arxiv_https___arxiv_org_abs_2410_11999
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Discovery of the Binarity of Gliese 229B, and Constraints on the System's Properties
Whitebook, Samuel
Brandt, Timothy
Brandt, Gregory Mirek
Martin, Emily
Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
We present two epochs of radial velocities of the first imaged T dwarf Gliese 229B obtained with Keck/NIRSPEC. The two radial velocities are discrepant with one another, and with the radial velocity of the host star, at $\approx$$11σ$ significance. This points to the existence of a previously postulated, but as-yet undetected, massive companion to Gl 229B; we denote the two components as Gl 229Ba and Gl 229Bb. We compute the joint likelihood of the radial velocities to constrain the period and mass of the secondary companion. Our radial velocities are consistent with an orbital period between a few days and $\approx$60 days, and a secondary mass of at least $\approx$15\,$M_{\rm Jup}$ and up to nearly half the total system mass of Gl 229B. With a significant fraction of the system mass in a faint companion, the strong tension between Gl 229B's dynamical mass and the predictions of evolutionary models is resolved.
title Discovery of the Binarity of Gliese 229B, and Constraints on the System's Properties
topic Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
url https://arxiv.org/abs/2410.11999