HD 72561

HD 72561 is a star in the constellation Hydra. Its apparent magnitude is 5.867.[2] Based on parallax shift, it is located about 1,600 light-years (500 parsecs) away.[1]

HD 72561

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Hydra
Right ascension	08^h 33^m 43.47908^s[1]
Declination	+04° 45′ 25.1949″[1]
Apparent magnitude (V)	5.867[2]
Characteristics
Spectral type	G5 III[3]
U−B color index	+0.87[4]
B−V color index	+1.07[4]
Astrometry
Radial velocity (Rv)	+1.60 ± 0.3[5] km/s
Proper motion (μ)	RA: −13.18[1] mas/yr Dec.: −6.84[1] mas/yr
Parallax (π)	1.98 ± 0.41[1] mas
Distance	approx. 1,600 ly (approx. 500 pc)
Details[6][note 1]
Mass	4.58 ± 0.40 M☉
Radius	48.41 ± 9.26 R☉
Luminosity	1109.6 ± 422.9 L☉
Surface gravity (log g)	1.80 ± 0.15 cgs
Temperature	4792 ± 36 K
Metallicity [Fe/H]	−0.16 ± 0.10 dex
Age	0.15 ± 0.04 Gyr
Other designations
BD+05° 1997, HIP 42008, HR 3378, SAO 116890[3]
Database references
SIMBAD	data

HD 72561 is a G-type giant star. It is over 4 times as massive as the Sun and 48 times as wide. It is about 150 million years old.[6]

References

1. van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
2. Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
3. "HR 3378". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 August 2017.
4. Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J.
5. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
6. Reffert, Sabine; Bergmann, Christoph; Quirrenbach, Andreas; Trifonov, Trifon; Künstler, Andreas (2015). "Precise radial velocities of giant stars". Astronomy & Astrophysics. 574: A116. arXiv:1412.4634. Bibcode:2015A&A...574A.116R. doi:10.1051/0004-6361/201322360. hdl:10722/215277.

Notes

1. The Reffert et al. paper gives two different sets of results, depending on whether the star is a horizontal branch star or a red giant branch star. The parameters given here are for a horizontal branch star, since the probability of it being a horizontal branch star is 99%.