HD 115337

HD 115337 is a binary star located in the northern circumpolar constellation Camelopardalis. The pair have a combined apparent magnitude of 6.25,^[2] placing it near the limit for naked eye visibility. Parallax measurements place the system at a distance of 698 light years.^[1] It has a heliocentric radial velocity of −9.4 km/s,^[5] indicating that it is drifting towards the Solar System.

HD 115337

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Camelopardalis
Right ascension	13h 12m 25.43269s[1]
Declination	+80° 28′ 16.7089″[1]
Apparent magnitude (V)	6.25[2] (6.33 + 9.04)[3]
Characteristics
Spectral type	G8 III + A8 V:[4]
B−V color index	+0.94[2]
Astrometry
Radial velocity (Rv)	−9.38±0.21[5] km/s
Proper motion (μ)	RA: −6.288 mas/yr[1] Dec.: +10.446 mas/yr[1]
Parallax (π)	4.6717 ± 0.0166 mas[1]
Distance	698 ± 2 ly (214.1 ± 0.8 pc)
Absolute magnitude (MV)	−0.32[6]
Details
A
Mass	3.4[1] M☉
Radius	16.4[1] R☉
Luminosity	161[1] L☉
Surface gravity (log g)	2.38[1] cgs
Temperature	5,160[1] K
Metallicity [Fe/H]	−0.13[1] dex
Rotational velocity (v sin i)	<1[7] km/s
Age	270[1] Myr
Other designations
AG+80°289, BD+81 416, FK5 3056, GC 17932, HD 115337, HIP 64437, HR 5009, SAO 2164, WDS J13124+8028A[8]
Database references
SIMBAD	data

The components have spectral classifications of K0 Ib^[9] and A8 V,^[4] indicating a K-type lower luminosity supergiant and an A-type main-sequence star (with uncertainty). At present the primary has 3.4 times the mass of the Sun and an enlarged radius of 16.4 R_☉ due to its evolved status. It radiates 161 times the luminosity of the Sun from its photosphere at an effective temperature of 5,160 K,^[10] giving a yellowish orange hue. HD 115337A is metal deficient, having an iron abundance only 74% of solar levels. Like most giants, it spins slowly with a projected rotational velocity of less than 1 km/s.^[7]

Ironically, the characteristics of HD 115337A belong to a giant star as opposed to a supergiant. It has even been classified as G5 III^[11] or G8 III,^[4] more consistent with the above properties. Nevertheless, optical measurements from Mason et al. (2001) find the pair to have a mean separation of an arcsecond along a position angle of 184°.^[12]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. Haggkvist, L.; Oja, T. (1970). "Results of BV photometry 1969-70 (Uppsala refractor)". Private Communication. Bibcode:1970Priv.........0H.
3. Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (March 2002). "The Tycho double star catalogue". Astronomy & Astrophysics. 384 (1): 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. ISSN 0004-6361.
4. Stephenson, C. B.; Sanwal, N. B. (June 1969). "The masses of stars above the main sequence". The Astronomical Journal. 74: 689. Bibcode:1969AJ.....74..689S. doi:10.1086/110845. ISSN 0004-6256.
5. Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
6. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
7. De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361.
8. "HR 5009". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 14, 2022.
9. Cowley, A. P.; Bidelman, W. P. (February 1979). "MK spectral types for some F and G stars". Publications of the Astronomical Society of the Pacific. 91: 83. Bibcode:1979PASP...91...83C. doi:10.1086/130446. eISSN 1538-3873. ISSN 0004-6280.
10. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881.
11. Adams, Walter S.; Joy, Alfred H.; Humason, Milton L.; Brayton, Ada Margaret (April 1935). "The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars". The Astrophysical Journal. 81: 187. Bibcode:1935ApJ....81..187A. doi:10.1086/143628. eISSN 1538-4357. ISSN 0004-637X.
12. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.

See also

• Red supergiant