 φ Herculis in optical light | |
| Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
|---|---|
| Constellation | Hercules |
| Right ascension | 16h 08m 46.17745s [1] |
| Declination | +44° 56′ 05.6663″ [1] |
| Apparent magnitude (V) | 4.24 [2] |
| Characteristics | |
| Spectral type | B9VspHgMn [3] + A8V [4] |
| U−B color index | −0.23 [2] |
| B−V color index | −0.06 [2] |
| Variable type | α2 CVn? [5] |
| Astrometry | |
| Radial velocity (Rv) | −16.3±0.4 [6] km/s |
| Proper motion (μ) |
RA: −26.63
[1]
mas/
yr Dec.: +36.76 [1] mas/ yr |
| Parallax (π) | 15.99 ± 0.45 mas [1] |
| Distance | 204 ± 6
ly (63 ± 2 pc) |
| Absolute magnitude (MV) | A: 0.100 ± 0.059 B: 2.670 ± 0.074 [7] |
| Orbit [7] | |
| 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 [4] km/s |
| Details | |
| φ Her A | |
| Mass | 3.05±0.24 [7] M☉ |
| Luminosity | 72 [8] L☉ |
| Surface gravity (log g) | 4.05±0.15 [4] cgs |
| Temperature | 11,525±150 [4] K |
| Metallicity [Fe/H] | −0.03 [7] dex |
| Rotational velocity (v sin i) | 8.0±1.0 [4] km/s |
| Age | 210 [7] Myr |
| φ Her B | |
| Mass | 1.614±0.066 [7] M☉ |
| Surface gravity (log g) | 4.30±0.15 [4] cgs |
| Temperature | 8,000±150 [4] K |
| Rotational velocity (v sin i) | 50.0±3.0 [4] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Phi Herculis (φ Her) is a binary star [4] system in the northern constellation of Hercules. Based upon an annual parallax shift of 15.99 mas as seen from Earth, [1] it is located around 204 light years from the Sun. With a combined apparent visual magnitude of 4.24, [2] 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. [7] The primary, component A, is a B-type main sequence star with a stellar classification of B9VspHgMn. [3] It is a chemically peculiar star of the type called a mercury-manganese star. [4] The star is tentatively catalogued as an Alpha2 Canum Venaticorum variable, with brightness variations of just 0.01 magnitudes. [5] [12]
The secondary, component B, was first separated via interferometry in 2004. [13] It is an A-type main sequence star of class A8V. [4] The magnitude difference between the two components is 2.64. [13]
- ^ a b c d e f 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.
- ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode: 1986EgUBV........0M.
- ^ a b 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.
- ^ a b c d e f g h i j k 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.
- ^ a b 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.
- ^ a b c d e f g 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.
- ^ a b 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.
φ Herculis in optical light | |
| Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
|---|---|
| Constellation | Hercules |
| Right ascension | 16h 08m 46.17745s [1] |
| Declination | +44° 56′ 05.6663″ [1] |
| Apparent magnitude (V) | 4.24 [2] |
| Characteristics | |
| Spectral type | B9VspHgMn [3] + A8V [4] |
| U−B color index | −0.23 [2] |
| B−V color index | −0.06 [2] |
| Variable type | α2 CVn? [5] |
| Astrometry | |
| Radial velocity (Rv) | −16.3±0.4 [6] km/s |
| Proper motion (μ) |
RA: −26.63
[1]
mas/
yr Dec.: +36.76 [1] mas/ yr |
| Parallax (π) | 15.99 ± 0.45 mas [1] |
| Distance | 204 ± 6
ly (63 ± 2 pc) |
| Absolute magnitude (MV) | A: 0.100 ± 0.059 B: 2.670 ± 0.074 [7] |
| Orbit [7] | |
| 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 [4] km/s |
| Details | |
| φ Her A | |
| Mass | 3.05±0.24 [7] M☉ |
| Luminosity | 72 [8] L☉ |
| Surface gravity (log g) | 4.05±0.15 [4] cgs |
| Temperature | 11,525±150 [4] K |
| Metallicity [Fe/H] | −0.03 [7] dex |
| Rotational velocity (v sin i) | 8.0±1.0 [4] km/s |
| Age | 210 [7] Myr |
| φ Her B | |
| Mass | 1.614±0.066 [7] M☉ |
| Surface gravity (log g) | 4.30±0.15 [4] cgs |
| Temperature | 8,000±150 [4] K |
| Rotational velocity (v sin i) | 50.0±3.0 [4] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Phi Herculis (φ Her) is a binary star [4] system in the northern constellation of Hercules. Based upon an annual parallax shift of 15.99 mas as seen from Earth, [1] it is located around 204 light years from the Sun. With a combined apparent visual magnitude of 4.24, [2] 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. [7] The primary, component A, is a B-type main sequence star with a stellar classification of B9VspHgMn. [3] It is a chemically peculiar star of the type called a mercury-manganese star. [4] The star is tentatively catalogued as an Alpha2 Canum Venaticorum variable, with brightness variations of just 0.01 magnitudes. [5] [12]
The secondary, component B, was first separated via interferometry in 2004. [13] It is an A-type main sequence star of class A8V. [4] The magnitude difference between the two components is 2.64. [13]
- ^ a b c d e f 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.
- ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode: 1986EgUBV........0M.
- ^ a b 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.
- ^ a b c d e f g h i j k 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.
- ^ a b 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.
- ^ a b c d e f g 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.
- ^ a b 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.