53 Camelopardalis

53 Camelopardalis is a binary star system in the northern circumpolar constellation of Camelopardalis,^[9] located 290 light years away from the Sun as determined by parallax measurements.^[2] It has the variable star designation AX Camelopardalis; 53 Camelopardalis is the Flamsteed designation.^[9] This object is dimly visible to the naked eye as a white hued star with a baseline apparent visual magnitude of +6.02.^[3] It is a single-lined spectroscopic binary^[10] system with an orbital period of 6.63 years and a high eccentricity of about 0.7.^[8] The "a sin i" value of the primary is 280 Gm (1.9 AU), where a is the semimajor axis and i is the orbital inclination.^[8]

53 Camelopardalis

A light curve for AX Camelopardalis, plotted from TESS data[1]
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Camelopardalis
Right ascension	08h 01m 42.43137s[2]
Declination	+60° 19′ 27.8016″[2]
Apparent magnitude (V)	6.02[3] (6.3 + 7.5)[4]
Characteristics
Evolutionary stage	main sequence
Spectral type	A3VpSrSiCrEu[5]
B−V color index	0.158±0.005[3]
Variable type	α2 CVn[6]
Astrometry
Radial velocity (Rv)	−2.2[3] km/s
Proper motion (μ)	RA: −21.367[2] mas/yr Dec.: −26.386[2] mas/yr
Parallax (π)	11.2327±0.1547 mas[2]
Distance	290 ± 4 ly (89 ± 1 pc)
Absolute magnitude (MV)	1.05[3]
Orbit[7]
Period (P)	6.6504±0.0089
Semi-major axis (a)	0.055±0.018″
Eccentricity (e)	0.706±0.024
Inclination (i)	55.4±2.9°
Longitude of the node (Ω)	118.3±20.1°
Periastron epoch (T)	2001.2281±0.025
Argument of periastron (ω) (secondary)	8.3±1.8°
Semi-amplitude (K1) (primary)	12.08±0.45[8] km/s
Details[8]
53 Cam A
Mass	2.074±0.012 M☉
Radius	2.36±0.10 R☉
Luminosity	24.9±1.15 L☉
Surface gravity (log g)	3.70±0.10 cgs
Temperature	8,400±150 K
Rotation	8.02681±0.00004 d
Rotational velocity (v sin i)	12.5±0.5 km/s
Age	615+56 −51 Myr
Other designations
53 Cam, AX Cam, BD+60°1105, FK5 302, GC 10822, HD 65339, HIP 39261, HR 3109, SAO 14402, CCDM 08017+6019, WDS J08017+6019[9]
Database references
SIMBAD	data

The visible component is a well-studied magnetic Ap star^[8] with a stellar classification of A3VpSrSiCrEu^[5] and a visual magnitude of 6.3.^[4] The magnetic field topology of 53 Camelopardalis is complex, and is accompanied by abundance variations across the surface of elements like silicon, calcium, titanium, iron, and neodymium.^[8]

Tadeusz Jarzębowski discovered that 53 Camelopardalis is a variable star, in 1960.^[11] It is classified as an Alpha² Canum Venaticorum type variable star and the combined brightness of the system varies from magnitude +6.00 down to +6.05 with a rotationally-modulated period of 8.0278 days.^[6]

The primary has 2.1 times the mass of the Sun and 2.4 times the Sun's radius. It is spinning with a projected rotational velocity of 12.5 km/s and a rotation period of 8.0268 days. The inclination angle of the pole is estimated to be 57°±5°. The star is about 615 million years old and is radiating 25 times the luminosity of the Sun from its photosphere at an effective temperature of 8,400 K.^[8]