HR 7135

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,^[11] in front of a dark rift in the Milky Way near the constellation border.^[6] It is visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.57.^[3] The system is located 283 light years distant from the Sun, based on parallax,^[2] and is drifting further away with a radial velocity of 23 km/s.^[6]

HR 7135

Observation data Epoch J2000      Equinox J2000
Constellation	Aquila[1]
Right ascension	18h 55m 27.46151s[2]
Declination	+06° 36′ 55.1499″[2]
Apparent magnitude (V)	5.57[3]
Characteristics
Evolutionary stage	red clump[4]
Spectral type	G9 III[5]
U−B color index	+0.87[3]
B−V color index	+1.041±0.002[1]
Astrometry
Radial velocity (Rv)	23.31±0.09[6] km/s
Proper motion (μ)	RA: +7.972[2] mas/yr Dec.: –92.211[2] mas/yr
Parallax (π)	11.5405±0.1636 mas[2]
Distance	283 ± 4 ly (87 ± 1 pc)
Absolute magnitude (MV)	0.87[1]
Orbit[6][7]
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[8] M☉
Radius	10.69+0.17 −0.93[2] R☉
Luminosity	52.8±0.9[2] L☉
Surface gravity (log g)	2.7[9] cgs
Temperature	4,666±51[8] K
Metallicity [Fe/H]	–0.26[9] dex
Rotational velocity (v sin i)	0.0[9] km/s
Age	3.21[8] Gyr
Other designations
62 Ser, BD+06°3978, FK5 3509, HD 175515, HIP 92872, HR 7135, SAO 124050[10]
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.^[6][7] The visible component is an aging giant star with a stellar classification of G9 III,^[5] having exhausted the supply of hydrogen at its core and expanded to 10.7^[2] 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.^[4] The star is 3.2^[8] billion years old with 1.54^[8] times the mass of the Sun. It is radiating 53^[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,666 K.^[8] The star has a very low rate of spin, with the projected rotational velocity being too small to measure.^[9]