Chi Herculis
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Hercules |
| Right ascension | 15h 52m 40.54105s |
| Declination | +42° 27′ 05.4629″ |
| Apparent magnitude (V) | 4.59 |
| Characteristics | |
| Spectral type | G0V Fe-0.8 CH-0.5 |
| U−B color index | +0.01 |
| B−V color index | +0.57 |
| Astrometry | |
| Radial velocity (Rv) | −55.99±0.12 km/s |
| Proper motion (μ) | RA: +448.839 mas/yr Dec.: +629.541 mas/yr |
| Parallax (π) | 62.0928±0.0807 mas |
| Distance | 52.53 ± 0.07 ly (16.10 ± 0.02 pc) |
| Absolute magnitude (MV) | +3.59 |
| Orbit | |
| Period (P) | 51.2865±0.4082 d |
| Semi-major axis (a) | 0.96±0.58″ |
| Eccentricity (e) | 0.0000 |
| Inclination (i) | 131.68±27.61° |
| Longitude of the node (Ω) | 51.69±37.96° |
| Periastron epoch (T) | 48349.0039±4.4425 |
| Argument of periastron (ω) (secondary) | 0.00° |
| Details | |
| Mass | 0.94±0.03 M☉ |
| Radius | 1.79+0.04 −0.03 R☉ |
| Luminosity | 3.30±0.18 L☉ |
| Surface gravity (log g) | 4.060±0.040 cgs |
| Temperature | 5,813+49 −56 K |
| Metallicity [Fe/H] | −0.45 dex |
| Rotational velocity (v sin i) | 2.4 km/s |
| Age | 9.18+0.65 −0.55 Gyr |
| Other designations | |
| χ Her, 1 Her, BD+42°2648, FK5 1166, GJ 602, HD 142373, HIP 77760, HR 5914, SAO 45772, WDS J16254+1402AB | |
| Database references | |
| SIMBAD | data |
Chi Herculis, Latinized from χ Herculis, is a Sun-like star in the northern constellation of Hercules. Based upon an annual parallax shift of 62.1 mas as seen from Earth, it is located 52.5 light years from the Sun. The star is faintly visible to the naked eye with an apparent visual magnitude of 4.59. It has a relatively high proper motion, showing a transverse movement of 0.769 arc seconds per year and is drifting closer to the Sun with a radial velocity of −56 km/s.
This is a suspected binary star system for which orbital elements have been published, listing a circular orbit with period of 51.3 days. However, sources do not confirm this and so the binarity remains in doubt. The observable component is a G-type main sequence star with a stellar classification of G0V Fe-0.8 CH-0.5, indicating abnormal deficiencies in iron and the CH molecule. The surface magnetic activity for this star is distinctly lower than the typical level for regular stars, and hence it is considered a good candidate for being in a Maunder minimum phase.
Chi Herculis is an older star with an estimated age of 7.4 billion years and is spinning with a projected rotational velocity of 2.4. It has 0.94 times the mass of the Sun and 1.79 times the Sun's radius. The star's photosphere is radiating 3.3 times the Sun's luminosity at an effective temperature of 5,813 K. Chi Herculis has been examined for the presence of an infrared excess that could indicate an orbiting debris disk, but none was found. The low metal content and a relatively high velocity of 80 kilometers per second suggest that the star is a visitor from another part of the Galaxy, and is just moving through the local neighborhood.
References
- 1 2 3 4 5 6 7 8 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- 1 2 3 4 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- 1 2 3 Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ↑ 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.
- 1 2 Hartkopf, W. I.; et al. (2006), Sixth Catalog of Orbits of Visual Binary Stars, archived from the original on 2011-05-17, retrieved 2017-04-03.
- 1 2 Harada, Caleb K.; et al. (June 2024), "Setting the Stage for the Search for Life with the Habitable Worlds Observatory: Properties of 164 Promising Planet-survey Targets", The Astrophysical Journal Supplement Series, 272 (2), id. 30, arXiv:2401.03047, Bibcode:2024ApJS..272...30H, doi:10.3847/1538-4365/ad3e81.
- 1 2 Fekel, F. C. (May 1997), "Rotational Velocities of Late-Type Stars", Publications of the Astronomical Society of the Pacific, 109: 514–523, Bibcode:1997PASP..109..514F, doi:10.1086/133908.
- ↑ "* chi Her", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-04-05.
- 1 2 Maldonado, J.; et al. (May 2012), "Metallicity of solar-type stars with debris discs and planets", Astronomy and Astrophysics, 541: A40, arXiv:1202.5884, Bibcode:2012A&A...541A..40M, doi:10.1051/0004-6361/201218800, S2CID 46328823.
- ↑ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.
- ↑ Rodriguez, David R.; et al. (May 2015), "Stellar multiplicity and debris discs: an unbiased sample", Monthly Notices of the Royal Astronomical Society, 449 (3): 3160–3170, arXiv:1503.01320, Bibcode:2015MNRAS.449.3160R, doi:10.1093/mnras/stv483.
- ↑ Hempelmann, A.; et al. (February 1996), "Coronal X-ray emission of late-type MS stars in relation to chromospheric activity and magnetic cycles", International Conference on X-ray Astronomy and Astrophysics: Röntgenstrahlung from the Universe, pp. 45–46, Bibcode:1996rftu.proc...45H.
- ↑ Kaler, Jim. "Chi Herculis". stars.astro.illinois.edu.
External links
- Kaler, Jim (8 Aug 2008), "Chi Her (Chi Herculis)", Stars, University of Illinois, retrieved 3 Jan 2013.
