Astronomy:72 Herculis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 20m 39.56754s[1] |
| Declination | +32° 28′ 03.8773″[1] |
| Apparent magnitude (V) | 5.377±0.005[2] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | G0 V[3] |
| U−B color index | +0.06[4] |
| B−V color index | +0.62[4] |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −78.608±0.0065[5] km/s |
| Proper motion (μ) | RA: +135.731[1] mas/yr Dec.: −1040.913[1] mas/yr |
| Parallax (π) | 68.7539 ± 0.0904 mas |
| Distance | 47.44 ± 0.06 ly (14.54 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.43±0.05[2] |
| Details | |
| Mass | 0.91 M☉[2] or 1.18[6] M☉ |
| Radius | 1.13+0.004 −0.007[1] R☉ |
| Luminosity | 1.331±0.003[1] L☉ |
| Surface gravity (log g) | 4.26±0.10[2] cgs |
| Temperature | 5,745±35[7] K |
| Metallicity [Fe/H] | −0.31±0.11[7] dex |
| Rotational velocity (v sin i) | 1.0±1.0[2] km/s |
| Age | 4.1–6.6[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
72 Herculis is a single[10] star in the northern constellation of Hercules. The Flamsteed designation for this star comes from the publication Historia Coelestis Britannica by John Flamsteed. It is the 72nd star in Flamsteed's list of stars in Hercules. This star is faintly visible to the naked eye with an apparent visual magnitude of 5.4.[2] Parallax measurements show this star to be located at a distance of about 47 light years from the Sun.[1] It is drifting closer with a radial velocity of −78.6 km/s,[5] and is predicted to come to within 32.1 light-years in around 98,000 years.[6]
This is an ordinary G-type main-sequence star with a stellar classification of G0 V. It is similar in mass to the Sun,[2] with a 13% larger radius.[1] The star is radiating 1.3[1] times the luminosity of the Sun from its photosphere at an effective temperature of 5,745 K.[7] The metallicity is much lower than in the Sun, with an [Fe/H] equal to −0.31±0.11.[7] The star is an estimated 4–7[8] billion years old with a projected rotational velocity of 1 km/s.[2] The level of chromospheric activity appears to be at or below that in the Sun.[11]
As of 2010, no planetary companion had been detected orbiting this star.[12] The Washington Visual Double Star Catalog for 1996 showed two visual companions of this star. The first is a visual magnitude 9.7 star located 289.1 arc seconds away. The second is only separated by 8.7 arc seconds, and is magnitude 12.9.[13] It is unknown whether these visual companions are gravitationally-bound to 72 Her.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 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. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Fuhrmann, Klaus (February 2008). "Nearby stars of the Galactic disc and halo - IV". Monthly Notices of the Royal Astronomical Society 384 (1): 173–224. doi:10.1111/j.1365-2966.2007.12671.x. Bibcode: 2008MNRAS.384..173F.
- ↑ Cenarro, A. J. et al. (July 2009). "Mg and TiO spectral features at the near-IR: spectrophotometric index definitions and empirical calibrations". Monthly Notices of the Royal Astronomical Society 396 (4): 1895–1914. doi:10.1111/j.1365-2966.2009.14839.x. Bibcode: 2009MNRAS.396.1895C.
- ↑ 4.0 4.1 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. SIMBAD. Bibcode: 1986EgUBV........0M.
- ↑ 5.0 5.1 Soubiran, C. et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics 616: A7. doi:10.1051/0004-6361/201832795. Bibcode: 2018A&A...616A...7S.
- ↑ 6.0 6.1 Bailer-Jones, C.A.L. et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics 616: A37. doi:10.1051/0004-6361/201833456. Bibcode: 2018A&A...616A..37B.
- ↑ 7.0 7.1 7.2 7.3 Stonkutė, E. et al. (2020). "High-resolution Spectroscopic Study of Dwarf Stars in the Northern Sky: Lithium, Carbon, and Oxygen Abundances". The Astronomical Journal 159 (3): 90. doi:10.3847/1538-3881/ab6a19. Bibcode: 2020AJ....159...90S.
- ↑ 8.0 8.1 Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal 687 (2): 1264–1293. doi:10.1086/591785. Bibcode: 2008ApJ...687.1264M.
- ↑ "72 Her". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=72+Her.
- ↑ Fuhrmann, K. et al. (February 2017). "Multiplicity among Solar-type Stars". The Astrophysical Journal 836 (1): 23. doi:10.3847/1538-4357/836/1/139. 139. Bibcode: 2017ApJ...836..139F.
- ↑ Hall, Jeffrey C. et al. (July 2009). "The Activity and Variability of the Sun and Sun-Like Stars. II. Contemporaneous Photometry and Spectroscopy of Bright Solar Analogs". The Astronomical Journal 138 (1): 312–322. doi:10.1088/0004-6256/138/1/312. Bibcode: 2009AJ....138..312H.
- ↑ Lubin, Dan et al. (June 2010). "Lithium Abundance in Solar-type Stars with Low Chromospheric Activity: Application to the Search for Maunder Minimum Analogs". The Astrophysical Journal 716 (1): 766–775. doi:10.1088/0004-637X/716/1/766. Bibcode: 2010ApJ...716..766L.
- ↑ Mason, B. D. et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal 122 (6): 3466–3471. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M.
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