R Arae

R Arae

Observation data Epoch J2000      Equinox J2000
Constellation	Ara
Right ascension	16^h 39^m 44.7306^s[1]
Declination	−56° 59′ 39.867″[1]
Apparent magnitude (V)	6.65[1]
Characteristics
Spectral type	B9IV/V[1]
B−V color index	0.09[1]
Variable type	Algol[2]
Astrometry
Proper motion (μ)	RA: -8.34[1] mas/yr Dec.: -18.85[1] mas/yr
Parallax (π)	8.06 ± 1.66[1] mas
Distance	approx. 400 ly (approx. 120 pc)
Absolute magnitude (MV)	1.18
Other designations
HIP 81589, CD-56° 6482, SAO 244037, HD 149730.
Database references
SIMBAD	data
Data sources:
Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.)

R Arae is an Algol-type eclipsing binary in the constellation Ara. Located approximately 124 parsecs (400 ly) distant,^[1] it normally shines at magnitude 6.17, but during eclipses can fall as low as magnitude 7.32.^[2] It has been suggested by multiple studies that mass transfer is occurring between the two stars of this system,^[3][4] and the period of eclipses seems to be increasing over time.^[4]

References

1. "R Arae". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 30 June 2014.
2. VSX (25 October 2010). "R Arae". AAVSO Website. American Association of Variable Star Observers. Retrieved 30 June 2014.
3. Nield, K. M. (1991). "Observations and analysis of the Southern binary R Arae". Astrophysics and Space Science 180 (2): 233. Bibcode:1991Ap&SS.180..233N. doi:10.1007/BF00648180.
4. Reed, P. A.; McCluskey Jr., G. E.; Kondo, Y.; Sahade, J.; Guinan, E. F.; Gimã©Nez, A.; Caton, D. B.; Reichart, D. E.; Ivarsen, K. M.; Nysewander, M. C. (2010). "Ultraviolet study of the active interacting binary star R Arae using archivalIUEdata". Monthly Notices of the Royal Astronomical Society 401 (2): 913. arXiv:0909.4047. Bibcode:2010MNRAS.401..913R. doi:10.1111/j.1365-2966.2009.15741.x.