Astronomy:HD 180262
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquila[1] |
| Right ascension | 19h 15m 20.08999s[2] |
| Declination | +15° 05′ 01.1456″[2] |
| Apparent magnitude (V) | 5.75[3] |
| Characteristics | |
| Spectral type | G8II-III[3] |
| U−B color index | +0.85[4] |
| B−V color index | +1.067±0.015[1] |
| R−I color index | 0.54 |
| Astrometry | |
| Radial velocity (Rv) | −25.2[5] km/s |
| Proper motion (μ) | RA: +1.178[2] mas/yr Dec.: −10.948[2] mas/yr |
| Parallax (π) | 5.392 ± 0.0624[2] mas |
| Distance | 605 ± 7 ly (185 ± 2 pc) |
| Absolute magnitude (MV) | −1.04[1] |
| Details | |
| Mass | 4.10+0.04−0.20[2] M☉ |
| Radius | 23.59+0.56−0.51[2] R☉ |
| Luminosity | 257.7+6.6−4.5[2] L☉ |
| Surface gravity (log g) | 2.245±0.001[2] cgs |
| Temperature | 4,910+2−3[2] K |
| Metallicity [Fe/H] | 0.21[6] dex |
| Rotational velocity (v sin i) | 1.4[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 180262 is one member of a wide double star in the equatorial constellation of Aquila. The pair have a combined apparent visual magnitude of 5.57,[4] which is bright enough to be dimly visible to the naked eye. Based on a parallax shift of 5.392 mas, it is located at a distance of 605 light-years (185 pc). It is drifting closer with a line of sight velocity component of −25 km/s.[5]
The pair have an angular separation of 89.823 arc second as of 2008.[3] The dual nature was discovered by Otto Struve and reported in 1875.[9] HD 180262 has a visual magnitude of 5.75[3] and a stellar classification of G8II-III.[3] It is presenting as an evolved giant star that has exhausted the supply of hydrogen at its core. With four times the mass of the Sun, the star has expanded to 24 times the Sun's radius. It is radiating 257 times the luminosity of the Sun from its photosphere at an effective temperature of 4,910 K.[2]
The secondary is HD 180243, an ordinary A-type main-sequence star with a class of A1V.[3] It is two magnitudes fainter than HD 180262, with a visual magnitude of 7.69.[3]
References
- ↑ 1.0 1.1 1.2 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.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 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.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 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
- ↑ 4.0 4.1 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode: 1986EgUBV........0M
- ↑ 5.0 5.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ Greenstein, Jesse L.; Keenan, Philip C. (January 1958), "Abundances of Metals, CN, and CH in Giant Stars", Astrophysical Journal 127: 172, doi:10.1086/146449, Bibcode: 1958ApJ...127..172G
- ↑ Lèbre, A.; de Laverny, P.; Do Nascimento, J. D. Jr.; de Medeiros, J. R. (May 2006), "Lithium abundances and rotational behavior for bright giant stars", Astronomy and Astrophysics 450 (3): 1173–1179, doi:10.1051/0004-6361:20053485, Bibcode: 2006A&A...450.1173L
- ↑ "HD 180262". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+180262.
- ↑ 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, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22.
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