Rho Telescopii

Rho Telescopii (ρ Tel, ρ Telescopii) is an astrometric binary^[9] star system in the southern constellation of Telescopium. It is visible to the naked eye, with an apparent visual magnitude of +5.17.^[2] Based upon an annual parallax shift of 17.63 mas as measured from Earth,^[1] it is located approximately 185 light years from the Sun.

Rho Telescopii

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Telescopium
Right ascension	19h 06m 19.95580s[1]
Declination	−52° 20′ 27.2757″[1]
Apparent magnitude (V)	+5.17[2]
Characteristics
Spectral type	F6 V[3]
B−V color index	+0.53[2]
Astrometry
Radial velocity (Rv)	+0.1±0.7[4] km/s
Proper motion (μ)	RA: +32.47[1] mas/yr Dec.: −115.24[1] mas/yr
Parallax (π)	17.63±0.59 mas[1]
Distance	185 ± 6 ly (57 ± 2 pc)
Absolute magnitude (MV)	1.69[5]
Details
Mass	1.97[4] M☉
Luminosity	25.6[6] L☉
Surface gravity (log g)	3.51[4] cgs
Temperature	6,303±80[4] K
Metallicity [Fe/H]	+0.01[7] dex
Rotational velocity (v sin i)	68.5±4.0[5] km/s
Age	1.30[4] Gyr
Other designations
ρ Tel, CPD−52°11356, HD 177171, HIP 93815, HR 7213, SAO 245921[8]
Database references
SIMBAD	data

This appears to be a single-lined spectroscopic binary as it displays radial velocity variation with a period of 1.7 days.^[9] The visible component is an F-type main sequence star with a stellar classification of F6 V.^[3] It has about double the mass of the Sun and is radiating 25.6^[6] times the solar luminosity from its photosphere at an effective temperature of 6,303 K.^[4] The star is a bright X-ray source with a luminosity of 65.76×10²⁹ ergs s⁻¹.^[10]

Relative to neighboring stars, Rho Telescopii has a peculiar velocity of 17.2 km s⁻¹.^[11] It may be a member of the Tucana-Horologium association.^[12]

Various age estimates

Age	Source
1.5±0.2 Myr	Tetzlaff et al. (2011)[11]
30 Myr	Lagrange et al. (2013)[9]
0.20 Gyr	Ballering et al. (2013)[13]
1.30 Gyr	Casagrande et al. (2011)[4]