Dynamical masses for two M1 + mid-M dwarf binaries monitored during the SPHERE-SHINE survey

Journal
ASTRONOMY & ASTROPHYSICS
Date Issued
2022
Author(s)
Beth A. Biller
•
Antoine Grandjean
•
MESSINA, Sergio
•
DESIDERA, Silvano
•
Philippe Delorme
•
Anne-Marie Lagrange
•
Franz-Josef Hambsch
•
MESA, Dino
•
Markus Janson
•
GRATTON, Raffaele
•
Valentina D'Orazi
•
Maud Langlois
•
Anne-Lise Maire
•
Joshua Schlieder
•
Thomas Henning
•
Alice Zurlo
•
Janis Hagelberg
•
S. Brown
•
C. Romero
•
Mickaël Bonnefoy
•
Gael Chauvin
•
Markus Feldt
•
Michael Meyer
•
Arthur Vigan
•
A. Pavlov
•
C. Soenke
•
D. LeMignant
•
A. Roux
DOI
Abstract
We present orbital fits and dynamical masses for HIP 113201AB and HIP 36985AB, two M1 + mid-M dwarf binary systems monitored as part of the SPHERE SHINE survey. To robustly determine ages via gyrochronology, we undertook a photometric monitoring campaign for HIP 113201 and for GJ 282AB, the two wide K star companions to HIP 36985, using the 40 cm Remote Observatory Atacama Desert (ROAD) telescope. We adopt ages of 1.2$\pm$0.1 Gyr for HIP 113201AB and 750$\pm$100 Myr for HIP 36985AB. To derive dynamical masses for all components of these systems, we used parallel-tempering Markov Chain Monte Carlo sampling to fit a combination of radial velocity, direct imaging, and Gaia and Hipparcos astrometry. Fitting the direct imaging and radial velocity data for HIP 113201 yields a primary mass of 0.54$\pm$0.03 M$_{\odot}$, fully consistent with its M1 spectral type, and a secondary mass of 0.145$\pm$ M$_{\odot}$. The secondary masses derived with and without including Hipparcos/Gaia data are more massive than the 0.1 M$_{\odot}$ estimated mass from the photometry of the companion. An undetected brown dwarf companion to HIP 113201B could be a natural explanation for this apparent discrepancy. At an age $>$1 Gyr, a 30 M$_{Jup}$ companion to HIP 113201B would make a negligible ($<$1$\%$) contribution to the system luminosity, but could have strong dynamical impacts. Fitting the direct imaging, radial velocity, and Hipparcos/Gaia proper motion anomaly for HIP 36985AB, we find a primary mass of 0.54$\pm$0.01 M$_{\odot}$ and a secondary mass of 0.185$\pm$0.001 M$_{\odot}$ which agree well with photometric estimates of component masses, the masses estimated from $M_{K}$-- mass relationships for M dwarf stars, and previous dynamical masses in the literature.
Volume
658
Start page
A145
Uri
Url
Issn Identifier
0004-6361
Ads BibCode
2022A&A...658A.145B
Rights
open.access