89 Herculis
 
| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 55m 25.18892s[1] |
| Declination | 26° 02′ 59.9738″[1] |
| Apparent magnitude (V) | 5.36[2] (5.34 - 5.54[3]) |
| Characteristics | |
| Evolutionary stage | post-AGB |
| Spectral type | F2Ibe[4] |
| U−B color index | −0.34[2] |
| B−V color index | +0.34[2] |
| Variable type | SRd[3] |
| Astrometry | |
| Radial velocity (Rv) | −28.5[5] km/s |
| Proper motion (μ) | RA: 4.34[1] mas/yr Dec.: 5.89[1] mas/yr |
| Parallax (π) | 0.76 ± 0.23[1] mas |
| Distance | approx. 4,000 ly (approx. 1,300 pc) |
| Absolute magnitude (MV) | −6.5[6] |
| Details | |
| Mass | 1.0[7] M☉ |
| Radius | 71.0[7] R☉ |
| Luminosity | 8,350[7] L☉ |
| Surface gravity (log g) | 0.55[4] cgs |
| Temperature | 6,550[4] K |
| Metallicity | −0.5[4] |
| Rotational velocity (v sin i) | 23[8] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
89 Herculis is a fifth-magnitude star in the constellation Hercules. Located about 4,000 light years away, it is among a rare class of post-AGB stars - low mass stars in the last stages of their lives, highly inflated to appear as supergiants.[4]
89 Her is a spectroscopic binary system with the pair surrounded by a dusty disc. The system shows variable brightness and spectral line profiles.[9] The companion has a very low mass and luminosity and orbits the primary in 288 days.[4]
89 Her is classified as a semiregular variable star, V441 Her, varying from magnitude 5.3 to 5.5 in around 68 days.[3]
References
- 1 2 3 4 5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752
. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. - 1 2 3 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
- 1 2 3 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- 1 2 3 4 5 6 Hillen, M.; Verhoelst, T.; Van Winckel, H.; Chesneau, O.; Hummel, C. A.; Monnier, J. D.; Farrington, C.; Tycner, C.; Mourard, D.; Ten Brummelaar, T.; Banerjee, D. P. K.; Zavala, R. T. (2013). "An interferometric study of the post-AGB binary 89 Herculis. I. Spatially resolving the continuum circumstellar environment at optical and near-IR wavelengths with the VLTI, NPOI, IOTA, PTI, and the CHARA Array". Astronomy & Astrophysics. 559: A111. arXiv:1308.6715. Bibcode:2013A&A...559A.111H. doi:10.1051/0004-6361/201321616.
- ↑ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington. Bibcode:1953GCRV..C......0W.
- ↑ Kipper, Tõnu (2011). "On the Optical Spectrum of 89 Her". Baltic Astronomy. 20: 65. Bibcode:2011BaltA..20...65K.
- 1 2 3 Hillen, M.; Menu, J.; Van Winckel, H.; Min, M.; Gielen, C.; Wevers, T.; Mulders, G. D.; Regibo, S.; Verhoelst, T. (2014). "An interferometric study of the post-AGB binary 89 Herculis. II. Radiative transfer models of the circumbinary disk". Astronomy & Astrophysics. 568: A12. arXiv:1405.1960. Bibcode:2014A&A...568A..12H. doi:10.1051/0004-6361/201423749.
- ↑ Hoffleit, Dorrit; Jaschek, Carlos (1991). "The Bright star catalogue". New Haven. Bibcode:1991bsc..book.....H.
- ↑ Burki, G.; Mayor, M.; Rufener, F. (1980). "Study of the Variable F-Type Supergiants HD161796 and HD163506 in Radial Velocity and Photometry". Astronomy and Astrophysics Supplement. 42: 383. Bibcode:1980A&AS...42..383B.
External links
- Jim Kaler's Stars, University of Illinois: 89 HER (89 Herculis)
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