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Variable B-type star in the constellation Aquarius
Omicron Aquarii ,
Latinized from ο Aquarii , is the
Bayer designation for a
variable star in the
equatorial
constellation of
Aquarius . Visible to the naked eye, it has an
apparent visual magnitude of +4.71.
[2]
Parallax measurements put it at a distance of roughly 440
light-years (130
parsecs ) from Earth.
[1] It is drifting further away with a
radial velocity of +11 km/s.
[5] The star is a candidate member of the
Pisces-Eridanus stellar stream .
[12]
It has the traditional star name Kae Uh , from the Chinese 蓋屋 (
Mandarin pronunciation Gài Wū ).
[13] In
Chinese astronomy , 蓋屋 is
the rooftop , an asterism consisting of ο Aquarii and
32 Aquarii .
[14] Consequently, the
Chinese name for ο Aquarii itself is 蓋屋一 (Gài Wū yī , English: the First Star of Roofing .)
[15]
A
light curve for Omicron Aquarii, plotted from
TESS data
[16]
The
spectrum of Omicron Aquarii fits a
stellar classification of B7 IVe;
[3] the
luminosity class of IV suggests that this is a
subgiant star that is exhausting the supply of hydrogen at its core and is in the process of
evolving into a
giant star . The 'e' suffix on the class indicates that the spectrum shows
emission lines of hydrogen, thus categorizing this as a
Be star . It is rotating rapidly with an equatorial rotational velocity of 368 km/s, which is ~96% of the star's
critical rotation velocity of 391 km/s.
[7] The emission lines are being generated by a
decreted circumstellar disk of hot hydrogen gas.
[10] This disk has been globally stable for at least twenty years, as of 2020.
[7] It is likely a single star, with no stellar companions.
[17]
Omicron Aquarii has 4.2 times the
mass of the Sun , four
[7] times the
Sun's radius , and is radiating 340
[6] times the
luminosity of the Sun from its
photosphere at an
effective temperature of 13,464 K.
[9] It is classified as a
Gamma Cassiopeiae type
[4] variable star and its brightness varies from magnitude +4.68 down to +4.89.
[18]
References
^
a
b
c
d
e
f van Leeuwen, F. (November 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 ,
S2CID
18759600 .
^
a
b
c
d Feinstein, A.; Marraco, H. G. (November 1979), "The photometric behavior of Be Stars", Astronomical Journal , 84 : 1713–1725,
Bibcode :
1979AJ.....84.1713F ,
doi :
10.1086/112600 .
^
a
b Lesh, Janet Rountree (December 1968).
"The Kinematics of the Gould Belt: an Expanding Group?" . Astrophysical Journal Supplement . 17 : 371.
Bibcode :
1968ApJS...17..371L .
doi :
10.1086/190179 .
^
a
b
"omi Aqr" ,
General Catalogue of Variable Stars , Sternberg Astronomical Institute, retrieved 2012-07-03 . Note: type = GCAS.
^
a
b Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg , 35 (35), Astronomisches Rechen-Institut Heidelberg: 1,
Bibcode :
1999VeARI..35....1W .
^
a
b
c
d 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 de Almeida, E. S. G.; et al. (April 2020), "Visible and near-infrared spectro-interferometric analysis of the edge-on Be star o Aquarii", Astronomy & Astrophysics , 636 : 23,
arXiv :
2002.09552 ,
Bibcode :
2020A&A...636A.110D ,
doi :
10.1051/0004-6361/201936039 ,
S2CID
211258993 , A110
^ Soubiran, C.; Le Campion, J.-F.; Cayrel de Strobel, G.; Caillo, A. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics , 515 : A111,
arXiv :
1004.1069 ,
Bibcode :
2010A&A...515A.111S ,
doi :
10.1051/0004-6361/201014247 ,
S2CID
118362423 .
^
a
b Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars",
Monthly Notices of the Royal Astronomical Society , 189 (3): 601–605,
Bibcode :
1979MNRAS.189..601U ,
doi :
10.1093/mnras/189.3.601 .
^
a
b Meilland, A.; Millour, F.; Kanaan, S.; Stee, Ph.; Petrov, R.; Hofmann, K.-H.; Natta, A.; Perraut, K. (February 2012), "First spectro-interferometric survey of Be stars. I. Observations and constraints on the disk geometry and kinematics", Astronomy & Astrophysics , 538 : A110,
arXiv :
1111.2487 ,
Bibcode :
2012A&A...538A.110M ,
doi :
10.1051/0004-6361/201117955 ,
S2CID
64777633 .
^
"omi Aqr" .
SIMBAD .
Centre de données astronomiques de Strasbourg . Retrieved 2012-07-03 .
^ Curtis, Jason L.; et al. (August 2019), "TESS Reveals that the Nearby Pisces-Eridanus Stellar Stream is only 120 Myr Old", The Astronomical Journal , 158 (2): 11,
arXiv :
1905.10588 ,
Bibcode :
2019AJ....158...77C ,
doi :
10.3847/1538-3881/ab2899 ,
S2CID
166228270 , 77.
^
Allen, R. H. (1963),
Star Names: Their Lore and Meaning (Reprint ed.), New York: Dover Publications Inc, p.
53 ,
ISBN
0-486-21079-0 , retrieved 2010-12-12 .
^ (in Chinese) 中國星座神話 , written by 陳久金. Published by 台灣書房出版有限公司, 2005,
ISBN
978-986-7332-25-7 .
^ (in Chinese)
AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 16 日
^
"MAST: Barbara A. Mikulski Archive for Space Telescopes" . Space Telescope Science Institute. Retrieved 8 December 2021 .
^ Hutter, D. J.; Tycner, C.; Zavala, R. T.; Benson, J. A.; Hummel, C. A.; Zirm, H. (2021).
"Surveying the Bright Stars by Optical Interferometry. III. A Magnitude-limited Multiplicity Survey of Classical Be Stars" . The Astrophysical Journal Supplement Series . 257 (2): 69.
arXiv :
2109.06839 .
Bibcode :
2021ApJS..257...69H .
doi :
10.3847/1538-4365/ac23cb .
S2CID
237503492 .
^ Ruban, E. V.; et al. (September 2006), "Spectrophotometric observations of variable stars", Astronomy Letters , 32 (9): 604–607,
Bibcode :
2006AstL...32..604R ,
doi :
10.1134/S1063773706090052 ,
S2CID
121747360 .
External links