1 Aquarii

1 Aquarii

Location of 1 Aqr (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Aquarius
Right ascension	20^h 39^m 24.8915^s[1]
Declination	+00° 29′ 11.201″[1]
Apparent magnitude (V)	5.16[2]
Characteristics
Spectral type	K1III[2]
U−B color index	+0.97
B−V color index	+1.06[2]
Astrometry
Radial velocity (Rv)	−42.81[3] km/s
Proper motion (μ)	RA: 101.95[1] mas/yr Dec.: −20.50[1] mas/yr
Parallax (π)	13.99 ± 0.65 mas
Distance	230 ± 10 ly (71 ± 3 pc)
Absolute magnitude (MV)	0.77[4]
Details
Temperature	3,500–5,000 K
Metallicity	−0.12[4]
Rotation	1.8[4]
Age	~5 × 10^9 years
Other designations
HR 7897, HD 196758, SAO 126062, BD +0 4064, FK5 3651, WDS J20394+0029, CCDM J20394+0029
Database references
SIMBAD	data
Data sources:
Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.)

1 Aquarii (abbreviated 1 Aqr) is a multiple star in the constellation Aquarius. 1 Aquarii is the Flamsteed designation. It is a K-class giant of the spectral type K1III. Its companions, B and C, are optical and have no physical relation to 1 Aqr A. 1 Aquarii is known to be an infra-red source.

Components

NAME	Right ascension	Declination	Apparent magnitude (V)	Database references
1 Aquarii B (BD-00 4064B)	20^h 39^m 21.8^s	+00° 28' 25	11.5	Simbad
1 Aquarii C (BD-00 4064C)	20^h 39^m 27.1^s	+00° 30' 07	11.3	Simbad

References

1. Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
2. Hoffleit, Dorrit; Jaschek, Carlos (1991). "The Bright star catalogue". New Haven. Bibcode:1991bsc..book.....H.
3. Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity". The Astronomical Journal 135: 209. Bibcode:2008AJ....135..209M. doi:10.1088/0004-6256/135/1/209.
4. Pace, G.; Pasquini, L.; Ortolani, S. (2003). "The Wilson-Bappu effect: A tool to determine stellar distances". Astronomy and Astrophysics 401 (3): 997. arXiv:astro-ph/0301637. Bibcode:2003A&A...401..997P. doi:10.1051/0004-6361:20030163.