Rho Tucanae

Rho Tucanae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Tucana
Right ascension 00h 42m 28.37188s
Declination −65° 28 04.9066
Apparent magnitude (V) +5.38
Characteristics
Spectral type F6 V
U−B color index +0.00
B−V color index +0.50
Astrometry
Radial velocity (Rv)33.962±0.796 km/s
Proper motion (μ) RA: +53.444 mas/yr
Dec.: +41.180 mas/yr
Parallax (π)23.6721±0.0631 mas
Distance137.8 ± 0.4 ly
(42.2 ± 0.1 pc)
Absolute magnitude (MV)+2.75
Orbit
Period (P)4.8202 d
Eccentricity (e)0.02
Periastron epoch (T)2419299.11 JD
Semi-amplitude (K1)
(primary)
26.1 km/s
Details
ρ Tuc A
Mass1.66 M
Luminosity9.7 L
Surface gravity (log g)3.64±0.11 cgs
Temperature6,034±54 K
Metallicity [Fe/H]−0.26 dex
Rotational velocity (v sin i)23.5±1.2 km/s
Age2.64 Gyr
ρ Tuc B
Mass0.33 M
Other designations
ρ Tuc, CPD−66°47, FK5 2047, HD 4089, HIP 3330, HR 187, SAO 248237
Database references
SIMBADdata

Rho Tucanae (ρ Tuc, ρ Tucanae) is a binary star system in the southern constellation of Tucana. It is visible to the naked eye with a combined apparent visual magnitude of +5.38. Based upon an annual parallax shift of 23.7 mas as seen from Earth, it is located 138 light years from the Sun.

This is a single-lined spectroscopic binary with a close, nearly circular orbit having a period of 4.82 days and an eccentricity of 0.02. The primary member, component A, is a yellow-white hued F-type main sequence star with a stellar classification of F6 V. It is around 2.6 billion years old and a member of the thin disk population. The primary has about 1.66 times the mass of the Sun while the secondary is just 0.33 times the Sun's mass.