Tau5 Serpentis

τ5 Serpentis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Serpens
Right ascension 15h 36m 29.240s
Declination +16° 07 08.70
Apparent magnitude (V) 5.93
Characteristics
Spectral type F3V
U−B color index +0.04
B−V color index +0.354±0.004
Astrometry
Radial velocity (Rv)−2.0±3.7 km/s
Proper motion (μ) RA: 72.175 mas/yr
Dec.: −5.217 mas/yr
Parallax (π)19.2694±0.0392 mas
Distance169.3 ± 0.3 ly
(51.9 ± 0.1 pc)
Absolute magnitude (MV)+2.35
Details
Mass1.54 M
Luminosity10 L
Surface gravity (log g)3.96 cgs
Temperature6,903±80 K
Metallicity [Fe/H]−0.20 dex
Rotational velocity (v sin i)88±10 km/s
Age1.90 Gyr
Other designations
τ5 Ser, 18 Serpentis, BD+16°2807, GC 20985, HD 139225, HIP 76424, HR 5804, SAO 101642, PPM 131544
Database references
SIMBADdata

Tau5 Serpentis, Latinized from τ5 Serpentis, is a star in the constellation of Serpens. The Flamsteed designation for this star is 18 Serpentis. It has an apparent visual magnitude of 5.93, which is bright enough to be dimly visible to the naked eye. The star is located at a distance of 169 light years from the Sun based on parallax measurements.

The stellar classification of this star is F3V, matching an F-type main-sequence star. It has 1.54 times the mass of the Sun and is radiating 10 times the Sun's luminosity from its photosphere at an effective temperature of 6,903 K. The star has an estimated age of 1.9 billion years and is spinning with a projected rotational velocity of about 88 km/s. It is metal poor, which means the abundance of iron in the stellar atmosphere is lower than in the Sun.