Searching for invisible binary companions of Be stars

• Grant number: 17/08001-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2017
• End date: July 31, 2019
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Alex Cavaliéri Carciofi
• Grantee: Amanda Caveagna Rubio
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 18/13285-7 - A truncation model for the Be star alpha col, BE.EP.MS

Abstract

Be stars are fast rotating main sequence stars that present a decretion disk around them. When these stars are in a close binary system, the presence of the companion affects the workings of the disk in various ways. One consequence of binarity in Be stars is the truncation of the disk. This truncation can be detected when we study the stellar spectral energy distribution (SED), as it produces a steepening of the spectral slope at long wavelengths (SED turndown). Recent studies have detected the radio SED turndown in several Be stars, and used it to estimate the orbit of the putative secondary. However, for only one object so far (beta CMi) the secondary was confirmed spectroscopically. The goal of this project is to follow-up on the detection of SED turndowns and search for the binaries with spectroscopy, aiming at both confirming their existence and estimating its orbital parameters. The spectroscopic detection of the otherwise unseen binaries will allow us to improve on the current statistics for binarity among Be stars. This work will contribute to one of the major issues regarding Be research, which is why and how some B stars acquire their fast rotation. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARR, K. C.; JONES, C. E.; CARCIOFI, A. C.; RUBIO, A. C.; MOTA, B. C.; GHOREYSHI, M. R.; HATFIELD, D. W.; RIMULO, L. R.. The Be Star 66 Ophiuchi: 60 Years of Disk Evolution. ASTROPHYSICAL JOURNAL, v. 912, n. 1, p. 15-pg., 2021-05-01. (18/04055-8, 17/08001-7, 18/13285-7, 09/54006-4)

RICHARDSON, NOEL D.; THIZY, OLIVIER; BJORKMAN, JON E.; CARCIOFI, ALEX; RUBIO, AMANDA C.; THOMAS, JOSHUA D.; BJORKMAN, KAREN S.; LABADIE-BARTZ, JONATHAN; GENARO, MATHEUS; WISNIEWSKI, JOHN P.; et al. utbursts and stellar properties of the classical Be star HD 622. Monthly Notices of the Royal Astronomical Society, v. 508, n. 2, p. 2002-2018, DEC 2021. (18/05326-5, 09/54006-4, 18/13285-7, 18/04055-8, 17/08001-7)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

RUBIO, Amanda Caveagna. Eyes on Phact: unraveling a Be star and its disk. 2019. Master's Dissertation - Universidade de São Paulo (USP). Instituto Astronômico e Geofísico (IAG/SBD) São Paulo.