Upsilon Gruis

Upsilon Gruis

Observation data Epoch J2000      Equinox J2000
Constellation	Grus
Right ascension	23^h 06^m 53.62552^s[1]
Declination	−38° 53′ 32.2484″[1]
Apparent magnitude (V)	5.614[2]
Characteristics
Spectral type	A1V[3]
B−V color index	+0.01[4]
Astrometry
Radial velocity (Rv)	+16[5] km/s
Proper motion (μ)	RA: +34.31[1] mas/yr Dec.: +6.40[1] mas/yr
Parallax (π)	11.45 ± 0.56[1] mas
Distance	280 ± 10 ly (87 ± 4 pc)
Details
Radius	2.2[6] R☉
Temperature	10,141 ± 290[2] K
Rotational velocity (v sin i)	320[7] km/s
Other designations
39 Tau, CD−39 14936, HD 218242, HIP 114132, HR 8790, SAO 214313.[8]

Upsilon Gruis is a double star in the southern constellation of Grus. The apparent magnitude is 5.61, which is bright enough to be viewed with the naked eye. Located around 87 parsecs (280 ly) distant, the primary is a blue-white main-sequence star of spectral type A1V, a star that is currently fusing its core hydrogen. it is spinning rapidly with a projected rotational velocity of 320 km/s. The companion is a magnitude 8.24 star at an angular separation of 0.90″ from the primary along a position angle of 205°, as of 2009.^[9]

References

1. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
2. Paunzen, E.; et al. (October 2006), "An empirical temperature calibration for the Δ a photometric system. II. The A-type and mid F-type stars", Astronomy and Astrophysics, 458 (1): 293–296, arXiv:astro-ph/0607567, Bibcode:2006A&A...458..293P, doi:10.1051/0004-6361:20064889.
3. Houk, Nancy (1979), Catalogue of two-dimensional spectral types for the HD stars, 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
4. Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
5. Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W.
6. Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition", Astronomy and Astrophysics, 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
7. Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
8. "ups Gru -- Double or multiple star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-02.
9. Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22