Astronomy:HD 156846
| Observation data {{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| Epoch J2000 [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}} | |
|---|---|
| Constellation | Ophiuchus[1] |
| A | |
| Right ascension | 17h 20m 34.31089s[2] |
| Declination | −19° 20′ 01.4917″[2] |
| Apparent magnitude (V) | 6.506[3] |
| B | |
| Right ascension | 17h 20m 34.31093s[4] |
| Declination | −19° 20′ 01.4944″[4] |
| Apparent magnitude (V) | 14.10[5] |
| Characteristics | |
| A | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G1V[6] |
| B−V color index | 0.557[3] |
| B | |
| Evolutionary stage | main sequence[7] |
| Spectral type | M4V[8] |
| Astrometry | |
| Radial velocity (Rv) | −68.50±0.22[9] km/s |
| Absolute magnitude (MV) | +3.055[3] |
| A | |
| Proper motion (μ) | RA: −137.076±0.029[2] mas/yr Dec.: −143.378±0.019[2] mas/yr |
| Parallax (π) | 20.9684 ± 0.0229[2] mas |
| Distance | 155.5 ± 0.2 ly (47.69 ± 0.05 pc) |
| Details | |
| A | |
| Mass | 1.35±0.045[3] M☉ |
| Radius | 2.12±0.12[3] R☉ |
| Luminosity | 5.07[9] L☉ |
| Surface gravity (log g) | 3.92±0.08[3] cgs |
| Temperature | 5,969±44[3] K |
| Metallicity [Fe/H] | +0.17±0.04[3] dex |
| Rotational velocity (v sin i) | 5.05±0.50[3] km/s |
| Age | 2.8+0.1 −0.2[9] Gyr |
| B | |
| Mass | 0.59[8] M☉ |
| Radius | 0.56[10] R☉ |
| Luminosity | 0.049[10] L☉ |
| Temperature | 3,592[10] K |
| Other designations | |
| A: BD−19°4605, GC 23420, SAO 160474 | |
| B: 2MASS J17203464-1919599 | |
| Database references | |
| SIMBAD | data |
| B | |
HD 156846 is a binary star[8] system in the equatorial constellation of Ophiuchus, positioned a degree SSE of Messier 9.[12] It has a yellow hue and is just barely bright enough to be visible to the naked eye with an apparent visual magnitude of 6.5. The system is located at a distance of 156 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −68.5 km/s, and is predicted to come to within 85.0 light-years in about 476,000 years.[9]
The primary, component A, is a G-type star with a stellar classification of G1V.[6] The absolute visual magnitude of this star is 1.13 magnitudes above the main sequence, indicating it has evolved slightly off the main sequence.[3] It has 1.35 times the mass of the Sun and 2.12 times the Sun's radius.[3] The star is an estimated 2.8[9] billion years old and is spinning with a projected rotational velocity of 5 km/s.[3] It is radiating five[9] times the luminosity of the Sun from its photosphere at an effective temperature of 5,969 K.[3]
The magnitude 14.1 secondary companion, component B, was discovered by the American astronomer R. G. Aitken in 1910.[5] It lies at an angular separation of 5.1″ from the primary, corresponding to a projected separation of 250 astronomical unit|AU. This is a red dwarf with a class of M4V and has an estimated 59% of the Sun's mass.[8]
Planetary system
On 26 October 2007, a planet HD 156846 b was found orbiting the primary star by Tamuz, using the radial velocity method.[13] It has an orbital period of 0.98 years and a large eccentricity of 0.85. The estimated mass of this object is, at a minimum, 10.6 times the mass of Jupiter. If it were following the same orbit within the Solar System, it would have a perihelion within the orbit of Mercury and an aphelion outside the orbit of Mars.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥10.57±0.29 MJ | 1.096±0.021 | 359.5546±0.0071 | 0.84785±0.00050 | — | — |
See also
- HD 4113
- List of extrasolar planets
References
- ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific 99 (617): 695. doi:10.1086/132034. Bibcode: 1987PASP...99..695R Constellation record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 Kane, Stephen R. et al. (May 2011). "Improved Orbital Parameters and Transit Monitoring for HD 156846b". The Astrophysical Journal 733 (1): 7. doi:10.1088/0004-637X/733/1/28. 28. Bibcode: 2011ApJ...733...28K.
- ↑ 4.0 4.1 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 Houk, N.; Smith-Moore, M. (1988). Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. 4. Bibcode: 1988mcts.book.....H.
- ↑ Tamuz, O.; Ségransan, D.; Udry, S.; Mayor, M.; Eggenberger, A.; Naef, D.; Pepe, F.; Queloz, D. et al. (2008). "The CORALIE survey for southern extra-solar planets. XV. Discovery of two eccentric planets orbiting HD 4113 and HD 156846". Astronomy and Astrophysics 480 (3): L33–L36. doi:10.1051/0004-6361:20078737. Bibcode: 2008A&A...480L..33T.
- ↑ 8.0 8.1 8.2 8.3 Fontanive, C. et al. (June 2019). "A high binary fraction for the most massive close-in giant planets and brown dwarf desert members". Monthly Notices of the Royal Astronomical Society 485 (4): 4967–4996. doi:10.1093/mnras/stz671. Bibcode: 2019MNRAS.485.4967F.
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 10.0 10.1 10.2 Hardegree-Ullman, Kevin K.; Apai, Dániel; Bergsten, Galen J.; Pascucci, Ilaria; López-Morales, Mercedes (2023). "Bioverse: A Comprehensive Assessment of the Capabilities of Extremely Large Telescopes to Probe Earth-like O2 Levels in Nearby Transiting Habitable-zone Exoplanets". The Astronomical Journal 165 (6): 267. doi:10.3847/1538-3881/acd1ec. Bibcode: 2023AJ....165..267H.
- ↑ "HD 156846". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+156846.
- ↑ Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. 3. Sky Publishing Corporation and the European Space Agency. ISBN 0-933346-84-0.
- ↑ Tamuz, O. et al. (2008). "The CORALIE survey for southern extra-solar planets XV. Discovery of two eccentric planets orbiting HD 4113 and HD 156846". Astronomy and Astrophysics 480 (3): L33–L36. doi:10.1051/0004-6361:20078737. Bibcode: 2008A&A...480L..33T. http://www.aanda.org/articles/aa/full/2008/12/aa8737-07/aa8737-07.html.
Coordinates: 
17h 20m 34.3100s, −19° 20′ 01.486″
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