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Star in the constellation Hercules
111 Herculis is a suspected
astrometric binary
[8]
star system located 92
light years from the Sun in the northern
constellation
Hercules . It is visible to the naked eye as a faint, white-hued point of light with an
apparent visual magnitude of 4.34.
[2] The system is moving nearer to the Earth with a heliocentric
radial velocity of −45 km/s, and may come as close as 37 light-years in 537,000 years.
[2]
According to Cowley et al. (1969), the visible component has a
stellar classification of A5III,
[3] matching an
A-type
giant star . Abt and Morrell (1995) listed it as type A3IV, suggesting it is instead a less
evolved
subgiant star .
[9] The
interferometry -measured
angular diameter of the primary component is 0.52± 0.02
mas ,
[10] which, at its estimated distance, equates to a physical radius of roughly 1.6 times the
radius of the Sun .
[5] The star is estimated to be 559
[4] million years old with 2.40
[4] times the
mass of the Sun and is spinning with a
projected rotational velocity of 71 km/s.
[4] It is radiating 13 times the
Sun's luminosity from its
photosphere at an
effective temperature of 8,873 K.
[4]
References
^
a
b
c
d
e
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
e
f
g 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 Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal , 74 : 375–406,
Bibcode :
1969AJ.....74..375C ,
doi :
10.1086/110819
^
a
b
c
d
e
f
g
h
i 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 .
^
a
b Lang, Kenneth R. (2006),
Astrophysical formulae , Astronomy and astrophysics library, vol. 1 (3rd ed.),
Birkhäuser ,
ISBN
3-540-29692-1 . The radius (R* ) is given by:
2
⋅
R
∗
=
(
10
−
3
⋅
28.3
⋅
0.52
)
AU
0.0046491
AU
/
R
⨀
≈
3.2
⋅
R
⨀
{\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(10^{-3}\cdot 28.3\cdot 0.52)\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 3.2\cdot R_{\bigodot }\end{aligned}}}
^ Erspamer, D.; North, P. (February 2003), "Automated spectroscopic abundances of A and F-type stars using echelle spectrographs. II. Abundances of 140 A-F stars from ELODIE", Astronomy and Astrophysics , 398 (3): 1121–1135,
arXiv :
astro-ph/0210065 ,
Bibcode :
2003A&A...398.1121E ,
doi :
10.1051/0004-6361:20021711 ,
S2CID
1109164 .
^
"111 Her" .
SIMBAD .
Centre de données astronomiques de Strasbourg . Retrieved 2019-06-18 .
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems",
Monthly Notices of the Royal Astronomical Society , 389 (2): 869–879,
arXiv :
0806.2878 ,
Bibcode :
2008MNRAS.389..869E ,
doi :
10.1111/j.1365-2966.2008.13596.x ,
S2CID
14878976 .
^ Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement , 99 : 135,
Bibcode :
1995ApJS...99..135A ,
doi :
10.1086/192182 .
^ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics , 431 (2): 773–777,
Bibcode :
2005A&A...431..773R ,
doi :
10.1051/0004-6361:20042039