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Star in the constellation Cygnus
Kappa Cygni ,
Latinized from κ Cygni, is a
star in the northern
constellation of
Cygnus . It has an
apparent visual magnitude of 3.8,
[2] which is bright enough to be seen with the naked eye. In the constellation, it forms the tip of Cygnus's left wing.
[9] The radiant of the minor
Kappa Cygnids
meteor shower is located about 5° north of this star.
[10]
Examination of this star's
spectrum show it to match a
stellar classification of G9 III,
[3] with the 'III'
luminosity class revealing that it has consumed the hydrogen fuel at its core and expanded into the
giant star stage of its
stellar evolution . It is known to vary in luminosity, but only by about 0.01 to 0.02 magnitudes.
[11] The measured
angular diameter of this star, after correction for
limb darkening , is 2.07 ± 0.09
mas .
[12] At an estimated distance of 124.2
light-years (38.1
parsecs ) based on
parallax measurements,
[1] this yields a physical size of about 8–9 times the
radius of the Sun .
[6] The outer envelope has an
effective temperature of 4,920 K,
[7] giving it the yellow-orange hue of a star near the transition from a G- to a K-type classification.
[13]
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 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants.",
Monthly Notices of the Royal Astronomical Society , 172 (3): 667–679,
Bibcode :
1975MNRAS.172..667J ,
doi :
10.1093/mnras/172.3.667
^
a
b Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics , 11 : 29–50,
Bibcode :
1973ARA&A..11...29M ,
doi :
10.1146/annurev.aa.11.090173.000333
^ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb , 35 , Veröffentlichungen des Astronomisches Rechen-Institut Heidelberg: 1,
Bibcode :
1999VeARI..35....1W
^
a
b 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 Lang, Kenneth R. (2006),
Astrophysical formulae , Astronomy and astrophysics library, vol. 1 (3 ed.),
Birkhäuser ,
ISBN
3-540-29692-1 . The radius (R* ) is given by:
2
⋅
R
∗
=
(
10
−
3
⋅
38.1
⋅
2.07
)
AU
0.0046491
AU
/
R
⨀
≈
17
⋅
R
⨀
{\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(10^{-3}\cdot 38.1\cdot 2.07)\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 17\cdot R_{\bigodot }\end{aligned}}}
^
a
b
c
d Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal , 135 (1): 209–231,
Bibcode :
2008AJ....135..209M ,
doi :
10.1088/0004-6256/135/1/209
^ Puzeras, E.; et al. (October 2010), "High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements", Monthly Notices of the Royal Astronomical Society , 408 (2): 1225–1232,
arXiv :
1006.3857 ,
Bibcode :
2010MNRAS.408.1225P ,
doi :
10.1111/j.1365-2966.2010.17195.x ,
S2CID
44228180
^ Consolmagno, Guy; Davis, Dan M. (2011),
Turn Left at Orion: Hundreds of Night Sky Objects to See in a Home Telescope - and How to Find Them (4th ed.),
Cambridge University Press , p. 134,
ISBN
978-0-521-15397-3
^ Stegmüller, Wolfgang (1979),
The structuralist view of theories: a possible analogue of the Bourbaki programme in physical science , Astronomers' Observing Guides, Springer, p. 82,
ISBN
0-387-09460-1
^ Adelman, Saul J. (2001), "On the Photometric Variability of Red Clump Giants", Baltic Astronomy , 10 (4): 593–597,
Bibcode :
2001BaltA..10..593A ,
doi :
10.1515/astro-2001-0404
^ 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
^
"The Colour of Stars" , Australia Telescope, Outreach and Education ,
Commonwealth Scientific and Industrial Research Organisation , December 21, 2004, archived from
the original on March 18, 2012, retrieved 2012-01-16