BRITE observations of $\nu$ Centauri and $\gamma$ Lupi, the first non-eclipsing members of the new class of nascent binaries

Abstract

Results of an analysis of the BRITE-Constellation and SMEI photometry and radial-velocity observations, archival and new, of two single-lined spectroscopic binary systems $\nu$ Centauri and $\gamma$ Lupi are reported. In the case of $\gamma$ Lup AB, a visual binary, an examination of the light-time effect shows that component A is the spectroscopic binary. Both $\nu$ Cen and $\gamma$ Lup exhibit light variations with the orbital period. The variations are caused by the reflection effect, i.e. heating of the secondary's hemisphere by the early-B main sequence (MS) primary component's light. The modelling of the light curves augmented with the fundamental parameters of the primary components obtained from the literature photometric data and Hipparcos parallaxes, shows that the secondary components are pre-MS stars, in the process of contracting onto the MS. $\nu$ Cen and $\gamma$ Lup A are thus found to be non-eclipsing counterparts of the B2 IV eclipsing binary (and a $\beta$ Cephei variable) 16 (EN) Lac, the B5 IV eclipsing binary (and an SPB variable) $\mu$ Eri, and the recently discovered LMC nascent eclipsing binaries.

15 pages, 15 figures, published in MNRAS

References in corpus (8)

• The Transiting Exoplanet Survey Satellite
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Populating the Galaxy with low-mass X-ray binaries
• The BRITE Constellation nanosatellite mission: Testing, commissioning and operations
• BRITE-Constellation: Data processing and photometry
• A New Class of Nascent Eclipsing Binaries with Extreme Mass Ratios
• Radial velocity measurements of B stars in the Scorpius-Centaurus association
• BRITE Cookbook 2.0

Cited by in corpus (4)

• Pulsating B stars in the Scorpius-Centaurus Association with TESS
• Multiples among B stars in the Scorpius-Centaurus association
• Tracing the evolution of short-period binaries with super-synchronous fast rotators
• Extreme mass ratios and fast rotation in three massive binaries