HD 31134

HD 31134, also designated as HR 1561, is a solitary star^[14] located in the northern circumpolar constellation Camelopardalis, the giraffe. It is faintly visible to the naked eye as a white-hued star with an apparent magnitude of 5.74.^[2] Gaia DR3 parallax measurements place it 473 light years away.^[1] It appears to be approaching the Solar System with a heliocentric radial velocity of −15.1 km/s.^[6] At its current distance, HD 31134's brightness is diminished by 0.35 magnitudes due to interstellar dust.^[15] It has an absolute magnitude of +0.19.^[7]

HD 31134

Location of HD 31134 on the map (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Camelopardalis
Right ascension	04h 56m 07.07238s[1]
Declination	+52° 52′ 11.0544″[1]
Apparent magnitude (V)	5.74±0.01[2]
Characteristics
Evolutionary stage	main sequence star[3]
Spectral type	A2 Vs[4] or A1 Vp[5]
U−B color index	+0.11[2]
B−V color index	+0.09[2]
Astrometry
Radial velocity (Rv)	−15.1±2.5[6] km/s
Proper motion (μ)	RA: −3.418 mas/yr[1] Dec.: +14.954 mas/yr[1]
Parallax (π)	6.8897 ± 0.1144 mas[1]
Distance	473 ± 8 ly (145 ± 2 pc)
Absolute magnitude (MV)	+0.19[7]
Details
Mass	2.74±0.05[3] M☉
Radius	4.38±0.22[8] R☉
Luminosity	103+13 −11[3] L☉
Surface gravity (log g)	3.85[9] cgs
Temperature	8,690[9] K
Metallicity [Fe/H]	−0.11[10] dex
Rotational velocity (v sin i)	60±1[11] km/s
Age	432[12] Myr
Other designations
AG+52°472, BD+52°898, GC 5988, HD 31134, HIP 22936, HR 1561, SAO 24919[13]
Database references
SIMBAD	data

The object has a stellar classification of A2 Vs,^[4] indicating that it is an A-type main-sequence star with sharp or narrow absorption lines due to slow rotation. Two sources remove the s prefix and instead list it as an ordinary dwarf star^[16][17] while one lists it as a more evolved giant star.^[18] Abt and Morell (1995) list it as a slightly hotter peculiar Ap star,^[5] but it is now considered unlikely to be chemically peculiar.^[19] It has 2.74 times the mass of the Sun and an enlarged radius of 4.38 R_☉.^[8] It radiates 103 times the luminosity of the Sun^[3] from its photosphere at an effective temperature of 8,690 K.^[9] HD 31134 is a rather evolved star, having completed 97.6% of its main sequence lifetime^[3] at the age of 432 million years.^[12] Consistent with its spectrum, it spins modestly with a projected rotational velocity of 60 km/s.^[11]

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. Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89: 415. Bibcode:1991A&AS...89..415O. ISSN 0365-0138.
3. Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars IV: Evolution of rotational velocities". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. eISSN 1432-0746. ISSN 0004-6361. S2CID 55586789.
4. Cowley, A.; Cowley, C.; Jaschek, M.; Jaschek, C. (April 1969). "A study of the bright stars. I. A catalogue of spectral classifications". The Astronomical Journal. 74: 375. Bibcode:1969AJ.....74..375C. doi:10.1086/110819. ISSN 0004-6256.
5. Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
6. 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. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
7. 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.
8. Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361.
9. Philip, A. G. D.; Egret, D. (May 1980). "An analysis of the Hauck-Mermillod catalogue of homogeneous four-color data. II". Astronomy and Astrophysics Supplement Series. 40: 199–205. Bibcode:1980A&AS...40..199P. ISSN 0365-0138.
10. Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361.
11. Royer, F.; Grenier, S.; Baylac, M.-O.; Gómez, A. E.; Zorec, J. (October 2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i". Astronomy & Astrophysics. 393 (3): 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. eISSN 1432-0746. ISSN 0004-6361.
12. Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. eISSN 1562-6873. ISSN 1063-7737.
13. "HR 1561". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved January 3, 2023.
14. Eggleton, P. P.; Tokovinin, A. A. (11 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. eISSN 1365-2966. ISSN 0035-8711. S2CID 14878976.
15. Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711.
16. Appenzeller, Immo (April 1967). "MK Spectral Types for 185 Bright Stars". Publications of the Astronomical Society of the Pacific. 79 (467): 102. Bibcode:1967PASP...79..102A. doi:10.1086/128449. eISSN 1538-3873. ISSN 0004-6280.
17. Cucchiaro, A.; Macau-Hercot, D.; Jaschek, M.; Jaschek, C. (July 1978). "Spectral classification from the ultraviolet line features of S2/68 spectra. III. Early A-type stars". Astronomy and Astrophysics Supplement Series. 33: 15–26. Bibcode:1978A&AS...33...15C. ISSN 0365-0138.
18. Palmer, D. R.; Walker, E. N.; Jones, D. H. P.; Wallis, R. E. (1968). "The radial velocities spectral types and projected rotational velocities of 633 bright northern A stars". Royal Greenwich Observatory Bulletins. 135: 385. Bibcode:1968RGOB..135..385P.
19. Renson, P.; Manfroid, J. (19 March 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy & Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788. eISSN 1432-0746. ISSN 0004-6361.