Discovery of an M-type companion to the Herbig Ae Star V1787 Ori. Issue 1 (24th November 2020)

• Record Type: Journal Article
• Authors: Arun, R; Mathew, Blesson; Rengaswamy, Sridharan; Manoj, P; Narang, Mayank; Kartha, Sreeja S; Maheshwar, G
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 501:Issue 1(2021)
• Page Start: 1243
• Page End: 1252
• Publication Date: 2020-11-24
• Subjects: binaries: visual -- stars: pre-main-sequence -- stars: variables: T Tauri, Herbig Ae/Be; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa3652
• Languages: English
• ISSNs: 0035-8711

Abstract

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 K s -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.