Discovery of an M-type companion to the Herbig Ae Star V1787 Ori
Abstract
The intermediate-mass Herbig Ae star V1787 Ori is a member of the L1641 star-forming region in the Orion A molecular cloud. We report the detection of an M-type companion to V1787 Ori at a projected separation of 6.66 arcsec (corresponding to 2577 au), from the analysis of VLT/NACO adaptive optics Ks-band image. Using astrometric data from Gaia DR2, we show that V1787 Ori A and B share similar distance (d ∼ 387 pc) and proper motion, indicating that they are physically associated. We estimate the spectral type of V1787 Ori B to be M5 ± 2 from colour-spectral type calibration tables and template matching using SpeX spectral library. By fitting PARSEC models in the Pan-STARRS colour-magnitude diagram, we find that V1787 Ori B has an age of 8.1 $^{+1.7}_{-1.5}$ Myr and a mass of 0.39 $^{+0.02}_{-0.05}$ M⊙. We show that V1787 Ori is a pre-main-sequence wide binary system with a mass ratio of 0.23. Such a low-mass ratio system is rarely identified in Herbig Ae/Be binary systems. We conclude this work with a discussion on possible mechanisms for the formation of V1787 Ori wide binary system.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2021
- DOI:
- 10.1093/mnras/staa3652
- arXiv:
- arXiv:2011.10222
- Bibcode:
- 2021MNRAS.501.1243A
- Keywords:
-
- binaries: visual;
- stars: pre-main-sequence;
- stars: variables: T Tauri;
- Herbig Ae/Be;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 10 pages,3 tables, 5 figures, accepted for publication in MNRAS