# Astronomy:HD 149989

Short description: Star in the constellation Ara
HD 149989
Observation data
Equinox J2000.0]] (ICRS)
Constellation Ara
Right ascension  16h 40m 44.39899s[1]
Declination −51° 28′ 41.7258″[1]
6.30[2]
Characteristics
Spectral type A9 V[3] or F1 V nn m-4[4]
B−V color index 0.321±0.006[5]
Variable type γ Dor[2]
Astrometry
Proper motion (μ) RA: +11.741[1] mas/yr
Dec.: +131.264[1] mas/yr
Parallax (π)19.5759 ± 0.0521[1] mas
Distance166.6 ± 0.4 ly
(51.1 ± 0.1 pc)
Absolute magnitude (MV)2.83[5]
Details
Mass1.60[7] M
−0.12
[1] R
Luminosity6.27±0.02[1] L
Surface gravity (log g)4.21±0.14[7] cgs
Temperature7,003+257
−159
[1] K
Rotational velocity (v sin i)136[8] km/s
Age1.144[7] Gyr
Other designations
V872 Arae, NSV 20726, CD–51°10403, CPD–51°9815, HD 149989, HIP 81650, SAO 244058[9]
Database references

HD 149989 is a single,[2] variable star in the southern constellation of Ara, located near the western constellation border with Norma. It has the variable star designation V872 Arae, while HD 149989 is the identifier from the Henry Draper Catalogue. This is a dim star near the lower limit of visibility to the naked eye with an apparent visual magnitude that fluctuates around 6.30.[2] It is located at a distance of 167 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 46 km/s.[6]

This object is an A-type main-sequence star with a stellar classification of A9 V.[3] A 2016 survey of γ Doradus stars found a class of F1 V nn m-4, where the 'nn' indicates "nebulous" lines due to rapid rotation and the 'm-4' means a metal-poor star with metal lines that match a class of A7.[4] This is a confirmed variable star of the Gamma Doradus type with a period of 0.42658 days.[2] It is around 1.1[7] billion years old and is spinning with a projected rotational velocity of 136 km/s.[8]

## References

1. Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
2. De Cat, P. et al. (April 2006), "A spectroscopic study of southern (candidate) γ Doradus stars. I. Time series analysis", Astronomy and Astrophysics 449 (1): 281–292, doi:10.1051/0004-6361:20053655, Bibcode2006A&A...449..281D
3. Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1978mcts.book.....H.
4. Kahraman Aliçavuș, F. et al. (May 2016), "Spectroscopic survey of γ Doradus stars - I. Comprehensive atmospheric parameters and abundance analysis of γ Doradus stars", Monthly Notices of the Royal Astronomical Society 458 (3): 2307–2322, doi:10.1093/mnras/stw393, Bibcode2016MNRAS.458.2307K.
5. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A.
6. Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode2006AstL...32..759G.
7. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode2015ApJ...804..146D.
8. Royer, F. et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode2007A&A...463..671R.