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Star in the constellation Norma
θ Normae , Latinised as Theta Normae , is a
binary star system in the
constellation
Norma . It has an
apparent visual magnitude of 5.13
[2] and is visible to the naked eye as a faint, blue-white-hued point of light. Based upon an annual
parallax shift of 9.27
mas as seen from Earth,
[5] this system is located about 352
light-years from the
Sun . At that distance, the visual magnitude of these stars is diminished by an
extinction of 0.45 due to
interstellar dust .
[12]
Chini et al. (2012) identified this as a single-lined
spectroscopic binary system.
[13] The visible component is a
B-type main-sequence star with a
stellar classification of B8 V.
[3] It is about 17
[7] million tears old and is spinning rapidly with a
projected rotational velocity of 251 km/s.
[10] The star has 3.6
[7] times the
mass of the Sun and 3.05
[8] times the
Sun's radius . It is radiating about 184 times the
Sun's luminosity from its
photosphere at an
effective temperature of 12,341
K .
[9] This system displays an
infrared excess , suggesting a
debris disk is orbiting at a mean radius of 21.8
AU with a temperature of 220 K.
[8]
References
^
a
b
Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018).
"Gaia Data Release 2: Summary of the contents and survey properties" .
Astronomy & Astrophysics . 616 . A1.
arXiv :
1804.09365 .
Bibcode :
2018A&A...616A...1G .
doi :
10.1051/0004-6361/201833051 .
Gaia DR2 record for this source at
VizieR .
^
a
b
c Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa , 27 : 11,
Bibcode :
1968MNSSA..27...11C .
^
a
b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars , vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan,
Bibcode :
1978mcts.book.....H .
^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics , 546 : 14,
arXiv :
1208.3048 ,
Bibcode :
2012A&A...546A..61D ,
doi :
10.1051/0004-6361/201219219 ,
S2CID
59451347 , A61.
^
a
b 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 ,
S2CID
18759600 .
^ 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 Gullikson, Kevin; et al. (2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", The Astronomical Journal , 152 (2): 40,
arXiv :
1604.06456 ,
Bibcode :
2016AJ....152...40G ,
doi :
10.3847/0004-6256/152/2/40 ,
S2CID
119179065 .
^
a
b
c Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series , 225 (1): 24,
arXiv :
1606.01134 ,
Bibcode :
2016ApJS..225...15C ,
doi :
10.3847/0067-0049/225/1/15 ,
S2CID
118438871 , 15.
^
a
b
c McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society , 427 (1): 343–57,
arXiv :
1208.2037 ,
Bibcode :
2012MNRAS.427..343M ,
doi :
10.1111/j.1365-2966.2012.21873.x ,
S2CID
118665352 .
^
a
b Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory , University of Kyoto,
Bibcode :
1970crvs.book.....U .
^
"tet Nor" .
SIMBAD .
Centre de données astronomiques de Strasbourg . Retrieved 2017-08-12 . {{
cite web }}
: CS1 maint: postscript (
link )
^ Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters , 38 (11): 694–706,
arXiv :
1606.09028 ,
Bibcode :
2012AstL...38..694G ,
doi :
10.1134/S1063773712110035 ,
S2CID
119108982 .
^ Chini, R.; et al. (2012), "A spectroscopic survey on the multiplicity of high-mass stars", Monthly Notices of the Royal Astronomical Society , 424 (3): 1925–1929,
arXiv :
1205.5238 ,
Bibcode :
2012MNRAS.424.1925C ,
doi :
10.1111/j.1365-2966.2012.21317.x ,
S2CID
119120749 .