 φ Herculis in optical light | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Hercules |
| Right ascension | 16 08 46.17745 |
| Declination | +44° 56′ 05.6663″ |
| Apparent magnitude (V) | 4.24 |
| Characteristics | |
| Spectral type | B9VspHgMn + A8V |
| U−B color index | −0.23 |
| B−V color index | −0.06 |
| Variable type | α CVn? |
| Astrometry | |
| Radial velocity (Rv) | −16.3±0.4 km/s |
| Proper motion (μ) | RA: −26.63 mas/yr Dec.: +36.76 mas/yr |
| Parallax (π) | 15.99 ± 0.45 mas |
| Distance | 204 ± 6 ly (63 ± 2 pc) |
| Absolute magnitude (MV) | A: 0.100 ± 0.059 B: 2.670 ± 0.074 |
| Orbit | |
| Period (P) | 564.834±0.038 d |
| Semi-major axis (a) | 32.027±0.028 mas |
| Eccentricity (e) | 0.52614±0.00086 |
| Inclination (i) | 9.1±0.4° |
| Longitude of the node (Ω) | 190.4±1.4° |
| Periastron epoch (T) | 2450121.43 ± 0.20 JD |
| Argument of periastron (ω) (secondary) | 350.3±1.4° |
| Semi-amplitude (K1) (primary) | 2.772±0.073 km/s |
| Semi-amplitude (K2) (secondary) | 8.1 km/s |
| Details | |
| φ Her A | |
| Mass | 3.05±0.24 M☉ |
| Luminosity | 72 L☉ |
| Surface gravity (log g) | 4.05±0.15 cgs |
| Temperature | 11,525±150 K |
| Metallicity | −0.03 dex |
| Rotational velocity (v sin i) | 8.0±1.0 km/s |
| Age | 210 Myr |
| φ Her B | |
| Mass | 1.614±0.066 M☉ |
| Surface gravity (log g) | 4.30±0.15 cgs |
| Temperature | 8,000±150 K |
| Rotational velocity (v sin i) | 50.0±3.0 km/s |
| Other designations | |
| φ Her, 11 Her, BD+45°2376, FK5 601, HD 145389, HIP 79101, HR 6023, SAO 45911. | |
| Database references | |
| SIMBAD | data |
Phi Herculis (φ Her) is a binary star system in the northern constellation of Hercules. Based upon an annual parallax shift of 15.99 mas as seen from Earth, it is located around 204 light years from the Sun. With a combined apparent visual magnitude of 4.24, it is bright enough to be seen with the naked eye.
This is a single-lined spectroscopic binary star system with an orbital period of 564.8 days and an eccentricity of 0.526. The primary, component A, is a B-type main sequence star with a stellar classification of B9VspHgMn. It is a chemically peculiar star of the type called a mercury-manganese star. The star is tentatively catalogued as an Alpha2 Canum Venaticorum variable, with brightness variations of just 0.01 magnitudes.
The secondary, component B, was first separated via interferometry in 2004. It is an A-type main sequence star of class A8V. The magnitude difference between the two components is 2.64.
References
- ^ van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
- ^ Zavala, R. T.; et al. (February 2007), "The Mercury-Manganese Binary Star φ Herculis: Detection and Properties of the Secondary and Revision of the Elemental Abundances of the Primary", The Astrophysical Journal, 655 (2): 1046–1057, arXiv:astro-ph/0610811, Bibcode:2007ApJ...655.1046Z, doi:10.1086/510108, S2CID 118994617.
- ^ Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ Torres, Guillermo (June 2007), "Astrometric-Spectroscopic Determination of the Absolute Masses of the HgMn Binary Star φ Herculis", The Astronomical Journal, 133 (6): 2684–2695, arXiv:astro-ph/0703193, Bibcode:2007AJ....133.2684T, doi:10.1086/516756, S2CID 11625161.
- McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
- "phi Her", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-04-05.
- Kochukhov, O.; Khalack, V.; Kobzar, O.; Neiner, C.; Paunzen, E.; Labadie-Bartz, J.; David-Uraz, A. (October 2021), "TESS survey of rotational and pulsational variability of mercury–manganese stars", Monthly Notices of the Royal Astronomical Society, 506 (4): 5328–5344, arXiv:2107.09096, doi:10.1093/mnras/stab2107.
- MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 8 December 2021.
- Kazarovets, E. V.; et al. (1999), "The 74th Special Name-list of Variable Stars", Information Bulletin on Variable Stars, 4659 (4659): 1, Bibcode:1999IBVS.4659....1K.
- ^ Zavala, R. T.; et al. (December 2004), "Detection of the Secondary of the HgMn star Phi Herculis with the Navy Prototype Optical Interferometer", Bulletin of the American Astronomical Society, 36: 1527, Bibcode:2004AAS...20510715Z.
| Constellation of Hercules | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Stars |
| ||||||||||||
| |||||||||||||
| |||||||||||||
| |||||||||||||
| Galaxies |
| ||||||||||||
| |||||||||||||
| |||||||||||||
 Category | |||||||||||||