HR 7135 is a binary star system. Despite its Flamsteed designation of 62 Serpentis, the star can be found in the equatorial constellation of Aquila,[10] in front of a dark rift in the Milky Way near the constellation border.[5] It is visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.57.[2] The system is located 283 light years distant from the Sun, based on parallax,[1] and is drifting further away with a radial velocity of 23 km/s.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 18h 55m 27.46151s[1] |
| Declination | +06° 36′ 55.1499″[1] |
| Apparent magnitude (V) | 5.57[2] |
| Characteristics | |
| Spectral type | G9 III[3] |
| U−B color index | +0.87[2] |
| B−V color index | +1.041±0.002[4] |
| Astrometry | |
| Radial velocity (Rv) | 23.31±0.09[5] km/s |
| Proper motion (μ) | RA: +7.972[1] mas/yr Dec.: –92.211[1] mas/yr |
| Parallax (π) | 11.5405 ± 0.1636 mas[1] |
| Distance | 283 ± 4 ly (87 ± 1 pc) |
| Absolute magnitude (MV) | 0.87[4] |
| Orbit[5][6] | |
| Primary | HR 7135 A |
| Companion | HR 7135 B |
| Period (P) | 2,994±29 d |
| Semi-major axis (a) | 26.6±3.4 mas |
| Eccentricity (e) | 0.243±0.026 |
| Inclination (i) | 31.9±3.6° |
| Longitude of the node (Ω) | 12.6±7.7° |
| Periastron epoch (T) | 2444276.5±52 JD |
| Argument of periastron (ω) (secondary) | 35±7° |
| Semi-amplitude (K1) (primary) | 4.65±0.13 km/s |
| Details | |
| HR 7135 A | |
| Mass | 1.54[7] M☉ |
| Radius | 10.69+0.17 −0.93[1] R☉ |
| Luminosity | 52.8±0.9[1] L☉ |
| Surface gravity (log g) | 2.7[8] cgs |
| Temperature | 4,666±51[7] K |
| Metallicity [Fe/H] | –0.26[8] dex |
| Rotational velocity (v sin i) | 0.0[8] km/s |
| Age | 3.21[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Discovery of the binary nature of this system is credited to Canadian astronomer H. H. Plaskett in 1922. It is a single-lined spectroscopic binary with an orbital period of 8.2 years and an eccentricity of 0.24.[5][6] The visible component is an aging giant star with a stellar classification of G9 III,[3] having exhausted the supply of hydrogen at its core and expanded to 10.7[1] times the Sun's radius. It is a red clump giant, indicating it is on the horizontal branch and is generating energy via core helium fusion.[11] The star is 3.2[7] billion years old with 1.54[7] times the mass of the Sun. It is radiating 53[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,666 K.[7] The star has a very low rate of spin, with the projected rotational velocity being too small to measure.[8]
References
edit- ^ a b c d e f g h i j 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 c Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527
- ^ a b 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, S2CID 119257644.
- ^ a b c d e Griffin, R. F. (1981), "Spectroscopic binary orbits from photoelectric radial velocities. Paper 41: HR 7135", The Observatory, 101: 208–211, Bibcode:1981Obs...101..208G.
- ^ a b Jancart, S.; et al. (2005), "Astrometric orbits of SB9 stars", Astronomy and Astrophysics, 442 (1): 365–380, arXiv:astro-ph/0507695, Bibcode:2005A&A...442..365J, doi:10.1051/0004-6361:20053003, S2CID 15123997.
- ^ a b c d e f 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, S2CID 118505114.
- ^ a b c d 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 175515". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-04.
- ^ Kaler, James B. (1996), The ever-changing sky: a guide to the celestial sphere, Cambridge University Press, p. 119, ISBN 0-521-38053-7.
- ^ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.