  | |
| Observation data Epoch J2000[1] Equinox J2000[1] | |
|---|---|
| Constellation | Hercules |
| Right ascension | 17h 30m 16.42797s |
| Declination | +47° 24′ 07.9010″ |
| Apparent magnitude (V) | 7.305[2] |
| Characteristics | |
| Spectral type | G9V Fe−0.8[3] |
| B−V color index | +0.830[2] |
| J−H color index | +0.338[4] |
| J−K color index | +0.412[4] |
| Astrometry | |
| Radial velocity (Rv) | −83.980 ± 0.0008[5] km/s |
| Proper motion (μ) | RA: 169.814[6] mas/yr Dec.: 77.133[6] mas/yr |
| Parallax (π) | 46.1856 ± 0.0042 mas[7] |
| Distance | 70.619 ± 0.006 ly (21.652 ± 0.002 pc) |
| Orbit[7] | |
| Primary | HD 159062 A |
| Companion | HD 159062 B |
| Period (P) | 411+71 −70 yr |
| Semi-major axis (a) | 2.860+0.320 −0.330" (61.9+7.0 −7.2 AU) |
| Eccentricity (e) | 0.102+0.11 −0.065 |
| Inclination (i) | 63.0+1.8 −2.4° |
| Longitude of the node (Ω) | 133.4+1.7 −1.3° |
| Periastron epoch (T) | 2507000+16000 −31000 |
| Argument of periastron (ω) (secondary) | 260+70 −76° |
| Details[8] | |
| HD 159062 A | |
| Mass | 0.80±0.05[7] M☉ |
| Radius | 0.76±0.04 R☉ |
| Surface gravity (log g) | 4.4±0.1 cgs |
| Temperature | 5283±100 K |
| Metallicity [Fe/H] | −0.31±0.06 dex |
| Rotational velocity (v sin i) | 2.06±0.5 km/s |
| Age | ~9–13[9] Gyr |
| HD 159062 B | |
| Mass | 0.6083+0.0083 −0.0073[7] M☉ |
| Temperature | 4580+440 −160 K |
| Age | cooling age: 8+3 −5[9] Gyr |
| Other designations | |
AG+47° 1251, BD+47° 2491, Gaia DR3 1362295082910131200, GC 23733, GJ 4010, HD 159062, HIP 85653, SAO 46762, PPM 56246, WDS J17303+4724A, LSPM J1730+4724, NLTT 44958, TIC 270258076, TYC 3513-1056-1, GSC 03513-01056, IRAS 17289+4726, 2MASS J17301639+4724078, WISEA J173016.61+472408.6, USNO-B1.0 1374-00341178[1] | |
| Database references | |
| SIMBAD | HD 159062 |
HD 159062 is a spectroscopic binary[1] consisting of a Sun-like star and a white dwarf positioned in the northern constellation of Hercules. With an apparent magnitude of 7.305, it is too faint to be seen by the naked eye but is readily visible via binoculars.[10] It is located at a distance of 70.619 light-years (21.652 parsecs) according to parallax calculations, and is approaching the Solar System at a heliocentric radial velocity of −83.980 km/s.
Stellar properties
[edit]The primary star, designated HD 159062 A, is a G-type main-sequence star slightly cooler than the Sun with 80% the mass and 76% the radius. It has the spectral type G9V Fe−0.8, where the "Fe−0.8" suffix indicates a slight but anomalous deficiency of metals like iron.[11] Indeed, it has a low metallicity of [Fe/H]=−0.31±0.06 dex. The star is thought to be ancient, somewhere between 9-13 billion years old, and has been marked as a population II star and a candidate blue straggler.[12] It rotates on its axis at roughly 2 km/s, about the same as the Sun's equatorial rotational velocity (1.997 km/s[13]).
Based on stellar kinematics, it is very likely (88% probability) a part of the thick disk population, and has been measured to have a europium abundance typical of thick disk stars. However, it is highly enhanced in s-process elements, such as barium, lanthanum, and cerium.[14] Fuhrmann et al. (2017) noted that the barium overabundance is particularly extreme at [Ba/Fe]=0.40 dex, which they argued was almost certainly the result of stellar wind accretion from a distant (orbital period 10-1,000 years) former asymptotic giant branch primary, which would have shriveled up into a cool white dwarf companion.[15]
As predicted, a white dwarf, HD 159062 B, was discovered in 2019 by Hirsch et al.[8] in a near-circular orbit around HD 159062 A at a distance of approximately 62 AU with a period of 411 years. The low eccentricity and large separation of the orbit implies that a Roche lobe overflow never took place.[7] It was once a ~1.5 M☉ star, whose lifespan came to an end roughly 8 billion years ago and has been radiating away heat as a stellar remnant ever since.[9] It has now cooled to an effective temperature of 4,580 K (4,310 °C; 7,780 °F). Its mass, together with its orbital parameters, was determined precisely using a Python script devised in 2021.[7]
See also
[edit]References
[edit]- ^ a b c "HD 159062". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 13 December 2024.
- ^ a b Høg, E.; et al. (February 2000). "The Tycho-2 Catalogue of the 2.5 Million Brightest Stars". Astronomy and Astrophysics. 355 (1): L27 – L30. Bibcode:2000A&A...355L..27H. Record for this source at VizieR.
- ^ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Robinson, P. E. (2003). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I." The Astronomical Journal. 126 (4): 2048–2059. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365. ISSN 0004-6256.
- ^ a b Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c d e f Brandt, Timothy D.; Dupuy, Trent J.; Li, Yiting; Brandt, G. Mirek; Zeng, Yunlin; Michalik, Daniel; Bardalez Gagliuffi, Daniella C.; Raposo-Pulido, Virginia (1 November 2021). "orvara: An Efficient Code to Fit Orbits Using Radial Velocity, Absolute, and/or Relative Astrometry". The Astronomical Journal. 162 (5): 186. arXiv:2105.11671. Bibcode:2021AJ....162..186B. doi:10.3847/1538-3881/ac042e. ISSN 0004-6256.
- ^ a b Hirsch, Lea A.; Ciardi, David R.; Howard, Andrew W.; Marcy, Geoffrey W.; Ruane, Garreth; Gonzalez, Erica; Blunt, Sarah; Crepp, Justin R.; Fulton, Benjamin J.; Isaacson, Howard; Kosiarek, Molly; Mawet, Dimitri; Sinukoff, Evan; Weiss, Lauren (10 June 2019). "Discovery of a White Dwarf Companion to HD 159062". The Astrophysical Journal. 878 (1): 50. arXiv:1905.06440. Bibcode:2019ApJ...878...50H. doi:10.3847/1538-4357/ab1b11. ISSN 0004-637X.
- ^ a b c Bowler, Brendan P.; Cochran, William D.; Endl, Michael; Franson, Kyle; Brandt, Timothy D.; Dupuy, Trent J.; MacQueen, Phillip J.; Kratter, Kaitlin M.; Mawet, Dimitri; Ruane, Garreth (1 March 2021). "The McDonald Accelerating Stars Survey (MASS): White Dwarf Companions Accelerating the Sun-like Stars 12 Psc and HD 159062". The Astronomical Journal. 161 (3): 106. arXiv:2012.04847. Bibcode:2021AJ....161..106B. doi:10.3847/1538-3881/abd243. ISSN 0004-6256.
- ^ Zarenski, Ed (2004). "Limiting Magnitude in Binoculars" (PDF). Cloudy Nights. Archived (PDF) from the original on 21 July 2011. Retrieved 6 May 2011.
- ^ Keenan, Philip C. (1987). "Spectral types and their uses". Publications of the Astronomical Society of the Pacific. 99: 713. Bibcode:1987PASP...99..713K. doi:10.1086/132036.
- ^ Fuhrmann, Klaus; Chini, Rolf; Kaderhandt, Lena; Chen, Zhiwei (21 January 2017). "On the local stellar populations". Monthly Notices of the Royal Astronomical Society. 464 (3): 2610–2621. doi:10.1093/mnras/stw2526. ISSN 0035-8711.
- ^ "Solar System Exploration: Planets: Sun: Facts & Figures". NASA. Archived from the original on 2 January 2008.
- ^ Brewer, Mary-Margaret; Carney, Bruce W. (2006). "A Comparison of the Chemical Evolutionary Histories of the Galactic Thin Disk and Thick Disk Stellar Populations". The Astronomical Journal. 131 (1): 431–454. arXiv:astro-ph/0509267. Bibcode:2006AJ....131..431B. doi:10.1086/498110. ISSN 0004-6256.
- ^ Fuhrmann, K.; Chini, R.; Kaderhandt, L.; Chen, Z.; Lachaume, R. (2017). "The barium-to-iron enrichment versus age relation of ancient disc stars". Monthly Notices of the Royal Astronomical Society. 471 (3): 3768–3774. doi:10.1093/mnras/stx1848. ISSN 0035-8711.
