R Coronae Australis

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R Coronae Australis
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Corona Australis
Right ascension 19h 01m 53.6503s[1]
Declination −36° 57′ 07.87″[1]
Apparent magnitude (V) +11.91
Characteristics
Spectral type B5IIIpe[1]
Variable type irregular[2]
Astrometry
Radial velocity (Rv) -36 km/s
Proper motion (μ) RA: -28.30 mas/yr
Dec.: 20.57 mas/yr
Parallax (π) 40.93 ± 27.95 mas
Distance approx. 80 ly
(approx. 20 pc)
Details
Other designations
AAVSO 1855-37A, CD-37 13027 HIP 93449

R Coronae Australis (R CrA) is variable star in the constellation Corona Australis.[1] It has varied between magnitudes 10 and 14.36.[2] A small reflection/emission nebula NGC 6729 extends from star towards SE.

This star is moving toward the Solar System with a radial velocity of 36 km s–1. In roughly 222,000 years, this system may approach within 1.77 light-years (0.54 parsecs) of the Sun. However, this estimate has a considerable margin of error, so the actual distance remains uncertain.[3]

A colour photo of the R Coronae Australis region in the southern Milky Way.

References[edit]

  1. ^ a b c d "R Coronae Australis". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 29 June 2014. 
  2. ^ a b BSJ (14 June 2010). "R Coronae Australis". AAVSO Website. American Association of Variable Star Observers. Retrieved 29 June 2014. 
  3. ^ Dybczyński, P. A. (April 2006), "Simulating observable comets. III. Real stellar perturbers of the Oort cloud and their output", Astronomy and Astrophysics 449 (3): 1233–1242, Bibcode:2006A&A...449.1233D, doi:10.1051/0004-6361:20054284