Summary
109 Herculis is a single[10] star in the northern constellation of Hercules. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 3.84.[2] The star is located around 118.8 light-years (36.4 parsecs) distant, based on parallax.[1] It is moving closer to the Earth with a heliocentric radial velocity of −58 km/s,[6] and may come as close as 81 light-years away in around 328,000 years.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 18h 23m 41.88967s[1] |
| Declination | +21° 46′ 11.0854″[1] |
| Apparent magnitude (V) | 3.84[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | K2IIIab[4] |
| B−V color index | 1.168±0.005[5] |
| Astrometry | |
| Radial velocity (Rv) | −57.55±0.27[6] km/s |
| Proper motion (μ) | RA: +196.027[1] mas/yr Dec.: -241.709[1] mas/yr |
| Parallax (π) | 27.4579 ± 0.2258 mas[1] |
| Distance | 118.8 ± 1.0 ly (36.4 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.87[7] |
| Details[8] | |
| Mass | 1.05±0.18 M☉ |
| Radius | 11.55+0.20 −0.19 R☉ |
| Luminosity | 56.9±0.5[1] L☉ |
| Surface gravity (log g) | 2.24 cgs |
| Temperature | 4,569±60 K |
| Metallicity [Fe/H] | −0.06 dex |
| Rotational velocity (v sin i) | 4.4[6] km/s |
| Age | 6.39±2.71 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K2IIIab.[4] It is a red clump giant,[3] meaning it on the horizontal branch and is generating energy through helium fusion at its core. The star is roughly six billion years old with slightly more mass than the Sun.[8] With the supply of hydrogen at its core exhausted, it has expanded to nearly 12 times the Sun's radius.[8] The star is radiating 57[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,569 K.[8]
This star, together with 93 Her, 95 Her, and 102 Her, were consist Cerberus, the obsolete constellation[11]
References edit
- ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b J. R., Ducati (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.
- ^ a b Puzeras, E.; et al. (October 2010), "High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements", Monthly Notices of the Royal Astronomical Society, 408 (2): 1225–1232, arXiv:1006.3857, Bibcode:2010MNRAS.408.1225P, doi:10.1111/j.1365-2966.2010.17195.x, S2CID 44228180.
- ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ^ a b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
- ^ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256.
- ^ a b c d Baines, Ellyn K.; et al. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal, 155 (1), 30, arXiv:1712.08109, Bibcode:2018AJ....155...30B, doi:10.3847/1538-3881/aa9d8b, S2CID 119427037.
- ^ "109 Her". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-06-18.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Ian Ridpath's Star Tales - Cerberus