Theta Gruis

Theta Gruis
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Grus
Right ascension	23h 06m 52.73046s
Declination	−43° 31′ 13.2857″
Apparent magnitude (V)	4.28 (4.51 + 6.84 + 7.80)
Characteristics
Spectral type	kF3VhF5mF5(II-III) + ? + G2V
U−B color index	+0.16
B−V color index	+0.42
Astrometry
Radial velocity (Rv)	+9.6 km/s
Proper motion (μ)	RA: −47.17 mas/yr ; Dec.: −13.49 mas/yr
Parallax (π)	24.73±0.45 mas
Distance	132 ± 2 ly ; (40.4 ± 0.7 pc)
Absolute magnitude (MV)	+1.25
Details
θ Gru A
Luminosity	27 L☉
Rotational velocity (v sin i)	64 km/s
Other designations
	θ Gru, CD−44°15149, HD 218227, HIP 114131, HR 8787, SAO 231444
Database references
SIMBAD	data

Theta Gruis, Latinized from θ Gruis, is a triple star^[3] system in the southern constellation of Grus. Its combined apparent visual magnitude is 4.28,^[2] which is bright enough to be seen with the naked eye. The system contains a magnetic Delta Delphini-like^[9] F5 star with a close fainter companion, plus a more distant G2 main sequence star.^[3]

Quick Facts Constellation, Right ascension ...

Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Grus
Right ascension	23^h 06^m 52.73046^s^[1]
Declination	−43° 31′ 13.2857″^[1]
Apparent magnitude (V)	4.28^[2] (4.51 + 6.84 + 7.80)^[3]
Characteristics
Spectral type	kF3VhF5mF5(II-III)^[4] + ? + G2V^[3]
U−B color index	+0.16^[2]
B−V color index	+0.42^[2]
Astrometry

Radial velocity (R_v)	+9.6^[5] km/s
Proper motion (μ)	RA: −47.17^[1] mas/yr Dec.: −13.49^[1] mas/yr
Parallax (π)	24.73±0.45 mas^[1]
Distance	132 ± 2 ly (40.4 ± 0.7 pc)
Absolute magnitude (M_V)	+1.25^[6]

Details
θ Gru A
Luminosity	27^[6] `L`_☉
Rotational velocity (v sin i)	64^[7] km/s

Other designations
θ Gru, CD−44°15149, HD 218227, HIP 114131, HR 8787, SAO 231444^[8]
Database references
SIMBAD	data

References