Star in the constellation Aquarius
χ Aquarii Location of χ Aquarii (circled)
Observation dataEpoch J2000 Equinox J2000 Constellation Aquarius [ 1] Right ascension 23h 16m 50.939s [ 2] Declination −07° 43′ 35.40″[ 2] Apparent magnitude (V)[ 3] Characteristics Spectral type M3 III[ 4] U−Bcolor index +1.60[ 5] B−Vcolor index +1.60[ 5] Variable type SRb ?[ 3] Astrometry Radial velocity (Rv )−13.72± 0.86[ 6] km/s Proper motion (μ)RA: −17.721mas /yr [ 2] Dec.: −13.676mas /yr [ 2] Parallax (π)6.1612± 0.2060 mas [ 2] Distance 530 ± 20 ly pc ) Absolute magnitude (MV )−1.43[ 1] Details Radius 142[ 7] R ☉ Luminosity 2,598[ 7] L ☉ Surface gravity (log g )0.128[ 7] cgs Temperature 3,456[ 7] K Other designations χ Aqr ,92 Aquarii ,AAVSO 2311-08BD −08 6076GC 32401HD 219576HIP 114939HR 8850SAO 146612PPM 207366[ 8] Database references SIMBAD data
Chi Aquarii is astar in theequatorial constellation ofAquarius . Its name is aBayer designation that isLatinized from χ Aquarii, and abbreviated Chi Aqr or χ Aqr. The distance to this star, based uponparallax measurements with a 7%margin of error ,[ 2] light-years (160parsecs ). It is visible to thenaked eye with anapparent visual magnitude of about 5.[ 3]
Alight curve for Chi Aquarii, plotted fromHipparcos [ 9] Thevariability of the brightness of Chi Aquarii was announced byJoel Stebbins andCharles Morse Huffer in 1928, based on observations made atWashburn Observatory .[ 10] semi-regular variable star and its brightness varies by an amplitude of 0.0636 in magnitude.[ 11] [ 12]
This is an agingred giant star with aspectral classification of M3 III.[ 4] core was exhausted, itevolved off themain sequence , expanding to about 142 times theradius of the Sun .[ 7] photosphere at aneffective temperature of 3,456 K.[ 7]
^a b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation",Astronomy Letters ,38 (5): 331,arXiv :1108.4971 Bibcode :2012AstL...38..331A ,doi :10.1134/S1063773712050015 ,S2CID 119257644 . ^a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023)."Gaia Data Release 3. Summary of the content and survey properties" .Astronomy and Astrophysics .674 : A1.arXiv :2208.00211 Bibcode :2023A&A...674A...1G .doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^a b c Samus, N. N.; Durlevich, O. V.; et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)",VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S ,1 ,Bibcode :2009yCat....102025S . ^a b Crampton, D.;Lloyd Evans, T. (1973), "Spectroscopic observations of M giant stars at the South Galactic Pole",Monthly Notices of the Royal Astronomical Society 162 :11– 15,Bibcode :1973MNRAS.162...11C ,doi :10.1093/mnras/162.1.11 ^a b Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System",Astronomy and Astrophysics Supplement Series ,34 :1– 49,Bibcode :1978A&AS...34....1N . ^ Famaey, B.; et al. (May 2009), "Spectroscopic binaries among Hipparcos M giants. I. Data, orbits, and intrinsic variations",Astronomy and Astrophysics ,498 (2):627– 640,arXiv :0901.0934 Bibcode :2009A&A...498..627F ,doi :10.1051/0004-6361/200810698 ,S2CID 18739721 . ^a b c d e f McDonald, I.; et al. (15 June 2017), "Fundamental parameters and infrared excesses of Tycho–Gaia stars",Monthly Notices of the Royal Astronomical Society ,471 (1):770– 791,arXiv :1706.02208 Bibcode :2017MNRAS.471..770M ,doi :10.1093/mnras/stx1433 eISSN 1365-2966 ,ISSN 0035-8711 . ^ "chi Aqr -- Semi-regular pulsating Star" ,SIMBAD ,Centre de Données astronomiques de Strasbourg , retrieved2012-07-05 .^ "/ftp/cats/more/HIP/cdroms/cats" ,Centre de Données astronomiques de Strasbourg , Strasbourg astronomical Data Center, retrieved15 October 2022 .^ Stebbins, Joel; Huffer, C. M. (1928),"The Constancy of the Light of Red Stars" ,Publications of the Washburn Observatory ,15 :137– 174,Bibcode :1928PWasO..15..137S , retrieved5 December 2024 . ^ Koen, Chris; Eyer, Laurent (March 2002), "New periodic variables from the Hipparcos epoch photometry",Monthly Notices of the Royal Astronomical Society ,331 (1):45– 59,arXiv :astro-ph/0112194 Bibcode :2002MNRAS.331...45K ,doi :10.1046/j.1365-8711.2002.05150.x S2CID 10505995 . ^ Tabur, V.; et al. (December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants",Monthly Notices of the Royal Astronomical Society ,400 (4):1945– 1961,arXiv :0908.3228 Bibcode :2009MNRAS.400.1945T ,doi :10.1111/j.1365-2966.2009.15588.x S2CID 15358380 .
