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Star located in the constellation Aquarius
HD 212771 , also named Lionrock , is a solitary star in the southern zodiac
constellation
Aquarius . It has an
apparent magnitude of 7.60,
[2] making it readily visible with binoculars but not the
naked eye .
Parallax measurements place the object at a distance of 364
light years ,
[1] and is currently receding with a
radial velocity of 15
km/s .
[5]
HD 212771 has a
stellar classification of G8 IV,
[3] indicating that it is a
subgiant evolving towards the
red giant branch after being an
F-type main-sequence star for 1.7
billion years .
[9] It has 156% the
mass of the Sun and 5 times its radius.
[7] It radiates at 11
solar luminosities
[8] from its slightly enlarged
photosphere at an
effective temperature of 5,003
K ,
[7] giving it a yellow-hue. Unlike most planetary hosts, HD 212771 is slightly metal deficient, and spins with a
projected rotational velocity of about 2
km/s .
[9]
Planetary system
In 2010, a group of astronomers at the
Keck Observatory surveyed several
subgiant stars for
extrasolar planets via
Doppler spectroscopy They happened to find a massive
Jupiter -like planet orbiting HD 212771.
[10]
HD 212771 is named Lionrock . The name was selected in the
NameExoWorlds campaign by
Hong Kong , during the 100th anniversary of the
IAU . It is named after the
Lion Rock . The planet is named Victoriapeak , after the
Victoria Peak .
[11]
[12]
References
^
a
b
c
d
e
Brown, A. G. A. ; et al. (Gaia collaboration) (2021).
"Gaia Early Data Release 3: Summary of the contents and survey properties" .
Astronomy & Astrophysics . 649 : A1.
arXiv :
2012.01533 .
Bibcode :
2021A&A...649A...1G .
doi :
10.1051/0004-6361/202039657 .
S2CID
227254300 . (Erratum:
doi :
10.1051/0004-6361/202039657e ) .
Gaia EDR3 record for this source at
VizieR .
^
a
b
c Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics . 355 : L27–L30.
Bibcode :
2000A&A...355L..27H .
ISSN
0004-6361 .
^
a
b Houk, N.; Smith-Moore, M. (1988). Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26°.0 to -12°.0 . Vol. 4.
Bibcode :
1988mcts.book.....H .
^ Paunzen, E. (May 2022).
"Catalogue of stars measured in the Geneva seven-colour photometric system" . Astronomy & Astrophysics . 661 : A89.
arXiv :
2111.04810 .
Bibcode :
2022A&A...661A..89P .
doi :
10.1051/0004-6361/202142355 .
eISSN
1432-0746 .
ISSN
0004-6361 .
^
a
b Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; Artur de la Villarmois, E.; Chavero, C.; Gómez, M.; Mauas, P. J. D. (26 January 2015).
"Stellar parameters and chemical abundances of 223 evolved stars with and without planets" . Astronomy & Astrophysics . 574 : A50.
arXiv :
1410.6422 .
Bibcode :
2015A&A...574A..50J .
doi :
10.1051/0004-6361/201424474 .
eISSN
1432-0746 .
ISSN
0004-6361 .
^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters . 38 (5): 331–346.
arXiv :
1108.4971 .
Bibcode :
2012AstL...38..331A .
doi :
10.1134/S1063773712050015 .
ISSN
1063-7737 .
S2CID
255204555 .
^
a
b
c
d
e
f
g Luhn, Jacob K.; Bastien, Fabienne A.; Wright, Jason T.; Johnson, John A.; Howard, Andrew W.; Isaacson, Howard (20 March 2019).
"Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts" . The Astronomical Journal . 157 (4): 149.
arXiv :
1811.03043 .
Bibcode :
2019AJ....157..149L .
doi :
10.3847/1538-3881/aaf5d0 .
eISSN
1538-3881 .
^
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
d Ghezzi, L. (June 2018), "Retired A Stars Revisited: An Updated Giant Planet Occurrence Rate as a Function of Stellar Metallicity and Mass", The Astrophysical Journal , 860 (2): 18,
arXiv :
1804.09082 ,
Bibcode :
2018ApJ...860..109G ,
doi :
10.3847/1538-4357/aac37c ,
S2CID
118969017
^ Johnson, John Asher; Howard, Andrew W.; Bowler, Brendan P.; Henry, Gregory W.; Marcy, Geoffrey W.; Wright, Jason T.; Fischer, Debra A.; Isaacson, Howard (June 2010).
"Retired A Stars and Their Companions. IV. Seven Jovian Exoplanets from Keck Observatory1" . Publications of the Astronomical Society of the Pacific . 122 (892): 701–711.
arXiv :
1003.3445 .
Bibcode :
2010PASP..122..701J .
doi :
10.1086/653809 .
eISSN
1538-3873 .
ISSN
0004-6280 .
^
"Approved names" . NameExoworlds . Retrieved 2020-01-02 .
^
"International Astronomical Union | IAU" . www.iau.org . Retrieved 2020-01-02 .