A search for OB stars in the field of the galactic OB association Bochum 7
arXiv:1804.10672 · doi:10.1051/0004-6361/201731661
Abstract
AIMS We plan to identify the members of the Bochum7 association by performing simultaneous astrometric and spectrophotometric analyses, and estimate its distance and evolutionary stage. METHODS. We used our own visual spectroscopic and UBV photometric data of a 30' x 30' region centered at R.A. = 8h44m47.2s, Decl = - 45d58m55.5s. This information enabled us to estimate the spectral classification and distance of all stars present in the region. The proper motion was analyzed with data of the UCAC5 catalog and was used to identify the members of this association. We added JHK data from 2MASS and IRAS catalogs to check for the presence of infrared (IR) excess stars. RESULTS. We found that Bochum7 is an OB association with at least 27 identified stellar members (l = 265.12d, b = -2.0d) at a distance of 5640 pc. Its proper motion is mu(alfa)cos(delta) = -4.92+-0.08 mas/yr, mu(delta) = 3.26+-0.08 mas/yr. We derived an average heliocentric radial velocity of 35 km/s and were able to confirm the binary nature of the (ALS 1135) system and detect four new binary star candidates. Analysis of data for massive Bo 7 star candidates points towards a young age (< 3x10^6 years old) for the association, although the presence of a previous episode of star formation remains to be analyzed.
arXiv comment10 pages, 6 figures, 9 tables (2 in the text, 6 in the Appendix and 1 in the CDS versión). Accepted for publication in Astronomy & Astrophysics
References in corpus (13)
- The Gaia mission
- Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
- Evolution of asymptotic giant branch stars II. Optical to far-infrared isochrones with improved TP-AGB models
- A Hipparcos census of the nearby OB associations
- New catalogue of optically visible open clusters and candidates
- UCAC5: New Proper Motions using Gaia DR1
- On the role of the WNH phase in the evolution of very massive stars: Enabling the LBV instability with feedback
- Gemini/GMOS search of massive binaries in the ionizing cluster of 30 Dor
- Spectroscopic study of the N159/N160 complex in the Large Magellanic Cloud
- GR 290 (Romano's Star): 2. Light history and evolutionary state
- The massive eclipsing system ALS 1135 and variable stars in the field of the distant OB association Bochum 7
- Physical parameters of the O6.5V+B1V eclipsing binary system LS 1135
- LSS 1135: an O-Type Spectroscopic Binary in the galactic OB association Bochum 7