U Aquarii

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U Aquarii
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Aquarius
Right ascension  22h 03m 19.6992s[1]
Declination −16° 37′ 35.288″[1]
Apparent magnitude (V) 10.6 to 15.9[2]
B−V color index 1.0[1]
V−R color index 0.4[1]
Variable type RCB[2]
Proper motion (μ) RA: 3.03[1] mas/yr
Dec.: −2.53[1] mas/yr
Parallax (π)3.58 ± 2.55[1] mas
Distanceapprox. 900 ly
(approx. 300 pc)
Absolute magnitude (MV)6[NB 1]
Other designations
U Aqr, BD−17 6424, HIP 108876.[1]
Database references

U Aquarii (U Aqr) is a star in the constellation of Aquarius.[1] It has an apparent visual magnitude which varies between 10.6 and 15.9.[2]

In 1999, U Aqr was proposed to be a Thorne-Zytkow object, instead of being a simple R Coronae Borealis variable.[3]


  1. ^ From apparent magnitude and parallax.


  1. ^ a b c d e f g h i V* U Aqr -- Variable Star of R CrB type, database entry, SIMBAD. Accessed on line November 10, 2009.
  2. ^ a b c U Aqr, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 10, 2009.
  3. ^ Andrew D. Vanture; Daniel Zucker; George Wallerstein (April 1, 1999). "Is U Aquarii a Thorne-Żytkow Object?". The Astrophysical Journal. 514 (2). Bibcode:1999ApJ...514..932V. doi:10.1086/306956.