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Binary star system in the constellation Horologium
Eta Horologii (η Horologii, η Hor) is a
binary star system
[3] in the southern
constellation of
Horologium . It is visible to the naked eye with a combined
apparent visual magnitude of 5.31.
[2] Based upon an annual
parallax shift of 21.95
mas as seen from Earth,
[1] it is located around 149
light years from the
Sun .
The orbit for this pair is not yet well constrained. They appear to have an
orbital period of three years and an
eccentricity of roughly 0.16.
[6] As of 2012, the pair have an
angular separation of 78.7 mas, which corresponds to a
projected separation of 3.6
AU .
[3] The primary member, component A, is an
A-type main sequence star with a
stellar classification of A6 V. The secondary, component B, has an inferred class of F0 V, which would indicate it is an
F-type main sequence star .
[3]
References
^
a
b
c
d
e
f 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 .
^
a
b
c Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory , 4 (99): 99,
Bibcode :
1966CoLPL...4...99J .
^
a
b
c
d Marion, L.; et al. (October 2014), "Searching for faint companions with VLTI/PIONIER. II. 92 main sequence stars from the Exozodi survey", Astronomy & Astrophysics , 570 : 12,
arXiv :
1409.6105 ,
Bibcode :
2014A&A...570A.127M ,
doi :
10.1051/0004-6361/201424780 ,
S2CID
8756486 , A127.
^ 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 Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics , 542 : A116,
arXiv :
1204.2459 ,
Bibcode :
2012A&A...542A.116A ,
doi :
10.1051/0004-6361/201118724 ,
S2CID
53666672 .
^
a
b Malkov, O. Yu.; et al. (2012), "Dynamical Masses of a Selected Sample of Orbital Binaries", Astronomy & Astrophysics , 546 : 5,
Bibcode :
2012A&A...546A..69M ,
doi :
10.1051/0004-6361/201219774 , A69.
^
a
b Asensio-Torres, R.; Janson, M.; Bonavita, M.; Desidera, S.; Thalmann, C.; Kuzuhara, M.; Henning, Th.; Marzari, F.; Meyer, M. R.; Calissendorff, P.; Uyama, T. (2018). "SPOTS: The Search for Planets Orbiting Two Stars. III. Complete sample and statistical analysis". Astronomy & Astrophysics . 619 : A43.
arXiv :
1807.08687 .
Bibcode :
2018A&A...619A..43A .
doi :
10.1051/0004-6361/201833349 .
S2CID
118953455 .
^ 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
c David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal , 804 (2): 146,
arXiv :
1501.03154 ,
Bibcode :
2015ApJ...804..146D ,
doi :
10.1088/0004-637X/804/2/146 ,
S2CID
33401607 .
^
"eta Hor -- Double or multiple star" , SIMBAD Astronomical Database ,
Centre de Données astronomiques de Strasbourg , retrieved 2017-04-25 .