49 Camelopardalis

49 Camelopardalis is a variable star in the northern circumpolar constellation of Camelopardalis,[8] located 313 light years from the Sun based on parallax measurements.[1] It has the variable star designation BC Camelopardalis; 49 Camelopardalis is the Flamsteed designation. This star is a challenge to view with the naked eye, having a baseline apparent visual magnitude of 6.50.[2] It is moving away from the Earth with a heliocentric radial velocity of +6.5 km/s.[2]

49 Camelopardalis

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Camelopardalis
Right ascension	07^h 46^m 27.41459^s[1]
Declination	+62° 49′ 49.8895″[1]
Apparent magnitude (V)	6.50[2] (6.43–6.48)[3]
Characteristics
Spectral type	A7VpSrCrEuSiKsn[4]
B−V color index	0.262±0.002[2]
Variable type	α^2 CVn[3]
Astrometry
Radial velocity (Rv)	6.5±0.5[2] km/s
Proper motion (μ)	RA: −36.63[5] mas/yr Dec.: −61.36[5] mas/yr
Parallax (π)	10.4369 ± 0.0566[1] mas
Distance	313 ± 2 ly (95.8 ± 0.5 pc)
Absolute magnitude (MV)	1.58[2]
Details[6]
Mass	1.92+0.14 −0.25 M☉
Radius	2.32±0.33 R☉
Luminosity	17.4+3.5 −2.9 L☉
Surface gravity (log g)	3.99±0.13 cgs
Temperature	7,740±460 K
Metallicity [Fe/H]	−3.40±0.16 dex
Rotation	4.28677±0.00003 d[7]
Rotational velocity (v sin i)	25.8±1.0 km/s
Age	891+489 −316 Myr
Other designations
49 Cam, BC Cam, BD+63°733, GC 10422, HD 62140, HIP 37934, HR 2977, SAO 14322[8]
Database references
SIMBAD	data

This is a magnetic chemically peculiar star[6] with a stellar classification of A7VpSrCrEuSiKsn,[4] indicating it is an A-type main-sequence star with overabundances of various elements including strontium and europium, as well as broad, "nebulous" lines. The magnetic field of 49 Camelopardalis shows a relatively complex structure, in combination with distinct abundance patterns across the surface.[9] It is classified as an Alpha² Canum Venaticorum type variable and its brightness varies from visual magnitude +6.43 down to +6.48 with a rotationally-modulated period of 4.29 days.[3]

49 Camelopardalis has 1.9 times the mass of the Sun and 2.3 times the Sun's radius. It is around 891[6] million years old and is spinning with a period of 4.29 days.[7] The star is radiating 17 times the luminosity of the Sun from its photosphere at an effective temperature of 7,740 K.[6]

References

1. 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.
2. 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.
3. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S.
4. Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement Series, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
5. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
6. Sikora, J.; et al. (February 2019), "A Volume-Limited Survey of mCP Stars Within 100pc I: Fundamental Parameters and Chemical Abundances", Monthly Notices of the Royal Astronomical Society, 483 (2): 2300–2324, arXiv:1811.05633, Bibcode:2019MNRAS.483.2300S, doi:10.1093/mnras/sty3105.
7. Sikora, J.; et al. (March 2019), "A volume-limited survey of mCP stars within 100 pc II: rotational and magnetic properties", Monthly Notices of the Royal Astronomical Society, 483 (3): 3127–3145, arXiv:1811.05635, Bibcode:2019MNRAS.483.3127S, doi:10.1093/mnras/sty2895.
8. "49 Cam". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-04-22.
9. Silvester, J.; et al. (October 2017), "The complex magnetic field topology of the cool Ap star 49 Cam", Monthly Notices of the Royal Astronomical Society, 471 (1): 962–975, arXiv:1706.09196, Bibcode:2017MNRAS.471..962S, doi:10.1093/mnras/stx1606.