HD 259440: THE PROPOSED OPTICAL COUNTERPART OF THE {gamma}-RAY BINARY HESS J0632+057
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015 (United States)
HD 259440 is a B0pe star that was proposed as the optical counterpart to the {gamma}-ray source HESS J0632+057. Here, we present optical spectra of HD 259440 acquired to investigate the stellar parameters, the properties of the Be star disk, and evidence of binarity in this system. Emission from the H{alpha} line shows evidence of a spiral density wave in the nearly edge-on disk. We find a best-fit stellar effective temperature of 27,500-30,000 K and a log surface gravity of 3.75-4.0, although our fits are somewhat ambiguous due to scattered light from the circumstellar disk. We derive a mass of 13.2-19.0 M{sub sun} and a radius of 6.0-9.6 R{sub sun}. By fitting the spectral energy distribution, we find a distance between 1.1 and 1.7 kpc. We do not detect any significant radial velocity shifts in our data, ruling out orbital periods shorter than one month. If HD 259440 is a binary, it is likely a long-period (>100 d) system.
- OSTI ID:
- 21471200
- Journal Information:
- Astrophysical Journal, Vol. 724, Issue 1; Other Information: DOI: 10.1088/0004-637X/724/1/306; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
A NEW TeV BINARY: THE DISCOVERY OF AN ORBITAL PERIOD IN HESS J0632+057
Multiwavelength Observation Campaign of the TeV Gamma-Ray Binary HESS J0632 + 057 with NuSTAR, VERITAS, MDM, and Swift