Astronomy:HD 175740
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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 |
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]
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
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Abt, H. A. (September 1985), "Visual multiples. VIII - 1000 MK types", Astrophysical Journal Supplement Series 59: 95–112, doi:10.1086/191064, Bibcode: 1985ApJS...59...95A
- ↑ 4.0 4.1 4.2 4.3 Bailer-Jones, C.A.L. et al. (2018), "New stellar encounters discovered in the second Gaia data release", Astronomy & Astrophysics 616: A37, doi:10.1051/0004-6361/201833456, Bibcode: 2018A&A...616A..37B.
- ↑ 5.0 5.1 5.2 5.3 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ 6.0 6.1 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, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ "HD 175740". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+175740.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Ramírez, I. et al. (June 2014), "Elemental Abundances of Solar Sibling Candidates", The Astrophysical Journal 787 (2): 17, doi:10.1088/0004-637X/787/2/154, 154, Bibcode: 2014ApJ...787..154R.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
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