HD 175740
HD 175740 is a single[8] star in the northern constellation of Lyra.[2] This object has an orange hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.46.[2] It is located at a distance of approximately 266 light years from the Sun based on parallax,[1] and has an absolute magnitude of 0.89.[2] The star is drifting closer with a radial velocity of −9.5 km/s, and is predicted to come as close as 31.7 light-years in around 8 million years.[4]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Lyra |
| Right ascension | 18h 54m 52.17758s[1] |
| Declination | +41° 36′ 09.7934″[1] |
| Apparent magnitude (V) | 5.46[2] |
| Characteristics | |
| Spectral type | K0III[3] |
| B−V color index | 1.034±0.004[2] |
| Astrometry | |
| Radial velocity (Rv) | −9.52±0.13[4] km/s |
| Proper motion (μ) | RA: −2.059[1] mas/yr Dec.: −2.234[1] mas/yr |
| Parallax (π) | 12.2448 ± 0.0874[1] mas |
| Distance | 266 ± 2 ly (81.7 ± 0.6 pc) |
| Absolute magnitude (MV) | 0.89[2] |
| Details | |
| Mass | 1.39[5] or 2.795[4] M☉ |
| Radius | 10.17+0.35 −0.73[1] R☉ |
| Luminosity | 49.90±0.45[1] L☉ |
| Surface gravity (log g) | 2.8[6] cgs |
| Temperature | 4,811+181 −81[1] K |
| Metallicity [Fe/H] | −0.01±0.06[2] dex |
| Rotational velocity (v sin i) | 4.0[6] km/s |
| Age | 4.78[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K0III,[3] having evolving off the main sequence after the supply of hydrogen at its core was exhausted. It is an estimated 4.78[5] billion years old with 1.39[5] times the mass of the Sun, although Bailer-Jones et al. (2018) give a higher estimate of 2.8[4] times the Sun's mass. The elemental composition of this star has made it the first giant to be a candidate solar sibling, suggesting it may have been born in the same star cluster as the Sun.[9] It has expanded to ten[1] times the girth of the Sun and is radiating 50[1] times the Sun's luminosity from its photosphere at an effective temperature of 4,811 K.[1]
HD 175740 has a magnitude 12.6 visual companion, located at an angular separation of 8.4″ along a position angle (PA) of 300°, as of 2013. A magnitude 11.5 companion lies at a separation of 24.1″ along a PA of 39°, as of 2014. Both were discovered by American astronomer G. W. Hough in 1887.[10]
References
- 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.
- 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.
- Abt, H. A. (September 1985), "Visual multiples. VIII - 1000 MK types", Astrophysical Journal Supplement Series, 59: 95–112, Bibcode:1985ApJS...59...95A, doi:10.1086/191064
- Bailer-Jones, C.A.L.; et al. (2018), "New stellar encounters discovered in the second Gaia data release", Astronomy & Astrophysics, 616: A37, arXiv:1805.07581, Bibcode:2018A&A...616A..37B, doi:10.1051/0004-6361/201833456.
- Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88.
- Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
- "HD 175740". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-02-09.
- Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
- Ramírez, I.; et al. (June 2014), "Elemental Abundances of Solar Sibling Candidates", The Astrophysical Journal, 787 (2): 17, arXiv:1405.1723, Bibcode:2014ApJ...787..154R, doi:10.1088/0004-637X/787/2/154, 154.
- Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.