KK Andromedae

Last updated
KK Andromedae
KKAndLightCurve.png
An ultraviole light curve of KK Andromedae, adapted from Hildebrandt (1975) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 01h 34m 16.62220s [2]
Declination +37° 14′ 13.8765″ [2]
Apparent magnitude  (V)5.90 [3]
Characteristics
Spectral type B9 IV [4]
U−B color index −0.3
B−V color index −0.067±0.001 [3]
Variable type α2 CVn
Astrometry
Radial velocity (Rv)−1.4±1.8 [5]  km/s
Proper motion (μ)RA: +5.719 [2]   mas/yr
Dec.: −21.238 [2]   mas/yr
Parallax (π)7.4585 ± 0.1156 [2]   mas
Distance 437 ± 7  ly
(134 ± 2  pc)
Absolute magnitude  (MV)+0.35 [6]
Details
Mass 3.07±0.06 [7]   M☉
Radius 2.7±0.4 [6]   R☉
Luminosity 91 [6]   L☉
Surface gravity (log g)3.914±0.020 [8]   cgs
Temperature 11,729±50 [8]   K
Rotation 0.67 days [6]
Rotational velocity (v sin i)163±10 [8]  km/s
Age 225 [9]   Myr
Other designations
KK And, BD+36° 277, HD  9531, HIP  7321, HR  446, SAO  54788 [10]
Database references
SIMBAD data

KK Andromedae, also known as HD 9531, is a variable star in the northern constellation of Andromeda. It has an apparent visual magnitude of 5.90, [3] which places it near the lower limit of visibility to the naked eye even under good viewing conditions. An Alpha2 Canum Venaticorum variable, it varies in brightness by 0.012 magnitude every 0.66 days. [11] Based upon an annual parallax shift of 7.5  mas [2] as seen from Earth, it is located around 437  light years from the Sun. At that distance, the brightness of the star is diminished by an extinction of 0.26 magnitude due to interstellar dust. [9]

Cowley et al. (1969) assigned this star a stellar classification of B9 IV, [4] which would indicate it is a B-type star in the subgiant stage that has exhausted the hydrogen supply at its core and is expanding. It is a catalogued as an Ap star that displays an abnormal silicon abundance, [12] but has been reported to actually be a helium-weak chemically peculiar star. [13] The star has just over three times the mass of the Sun [7] and about 2.7 [6] times the Sun's radius. It is an estimated 225 [9]  million years old and is spinning rapidly with a projected rotational velocity of 163 km/s [8] and a rotation period of 16 hours. [6] KK And is radiating 91 [6] times the Sun's luminosity from its photosphere at an effective temperature of 11,729 K. [8]

Related Research Articles

101 Piscium is a star in the zodiac constellation of Pisces, located around 1,400 light years away from the Sun. This appears as a dim, blue-white hued star near the lower limit of visibility to the naked eye at an apparent visual magnitude of 6.23. It is a suspected variable star with the designation NSV 559; 101 Piscium is the Flamsteed designation. The star is moving closer to the Earth with a heliocentric radial velocity of −10 km/s.

Iota Andromedae Star in the constellation of Andromeda

Iota Andromedae is a single star in the northern constellation of Andromeda. It has the Flamsteed designation 17 Andromedae, while Iota Andromedae is the Bayer designation as Latinized from ι Andromedae. This object is visible to the naked eye at night as a faint, blue-white hued star with an apparent visual magnitude of +4.29. Based upon parallax measurements, it is located approximately 500 light years distant from the Sun.

Tau Andromedae Star in the constellation Andromeda

Tau Andromedae, Latinized from τ Andromedae, is the Bayer designation for a single star in the northern constellation of Andromeda. It has an apparent visual magnitude of +4.94, which is bright enough to be viewed from dark suburban skies. From parallax measurements made during the Hipparcos mission, the distance to this star can be estimated as roughly 710 light-years from Earth. The brightness of this star is diminished by 0.24 in magnitude due to extinction caused by intervening gas and dust. It is drifting closer to the Sun with a radial velocity of −14 km/s.

Rho Andromedae Star in the constellation Andromeda

Rho Andromedae, Latinized from ρ Andromedae, is the Bayer designation for a star in the northern constellation of Andromeda. It has an apparent visual magnitude of +5.19, which, according to the Bortle Dark-Sky Scale, is bright enough to be seen with the naked eye from dark suburban skies. Based upon parallax measurements, this star is at a distance of approximately 162 light-years from the Sun. It is drifting further away with a radial velocity of +10 km/s.

8 Andromedae, abbreviated 8 And, is a probable triple star system in the northern constellation of Andromeda. 8 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.82. Based upon an annual parallax shift of 6.1 mas, it is located 540 light years from the Earth. It is moving closer with a heliocentric radial velocity of −8 km/s.

2 Andromedae, abbreviated 2 And, is a binary star system in the northern constellation of Andromeda. 2 Andromedae is the Flamsteed designation. It is a faint star system but visible to the naked eye with a combined apparent visual magnitude of 5.09. Based upon an annual parallax shift of 7.7 mas, it is located 420 light years away. The binary nature of the star was discovered by American astronomer Sherburne Wesley Burnham at Lick Observatory in 1889. The pair orbit each other over a period of 74 years with a high eccentricity of 0.8.

18 Andromedae, abbreviated 18 And, is a single star in the northern constellation of Andromeda. 18 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 5.350. The annual parallax shift of 7.9 mas can be used to estimate a distance of 413 light years. It is moving further from the Earth with a heliocentric radial velocity of +10 km/s.

13 Andromedae Star in the constellation Andromeda

13 Andromedae, abbreviated 13 And, is a single, blue-white hued variable star in the northern constellation of Andromeda. 13 Andromedae is the Flamsteed designation, while it bears the variable star designation V388 Andromedae. With a typical apparent visual magnitude of around 5.75, it is dimly visible to the naked eye under good seeing conditions. The distance to this star can be directly estimated from its annual parallax shift of 10.9 mas, yielding a range of 300 light years. At that distance, its brightness is diminished by an extinction of 0.13 magnitude due to interstellar dust. The star is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.

26 Andromedae, abbreviated 26 And, is an astrometric binary star system in the constellation Andromeda. 26 Andromedae is the Flamsteed designation. It has a combined apparent visual magnitude of 6.10, which is near the lower limit of visibility to the naked eye. The distance to this system can be estimated from its annual parallax shift of 5.35 mas, which yields a range of 610 light years. At that distance, the visual magnitude of the stars is diminished from an extinction of 0.04 due to interstellar dust. The system is moving further from the Earth with a heliocentric radial velocity of +3.3 km/s.

Omega Cassiopeiae Binary star system in constellation Cassiopeia

Omega Cassiopeiae is a binary star system in the northern constellation of Cassiopeia. It has a combined apparent visual magnitude of +4.99, which means it is a faint star but visible to the naked eye. Based upon an annual parallax shift of 4.65 mas as seen from Earth, this system is located roughly 700 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.16 due to interstellar dust.

HD 3240 is a single star in the northern constellation of Cassiopeia, positioned near Zeta Cassiopeiae. This object has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.08. The distance to HD 3240 is approximately 480 light years based on parallax. At that range, the visual magnitude of the star is diminished by an extinction of 0.22 due to interstellar dust.

HD 222109 is a binary star system in the northern constellation of Andromeda. They have a combined apparent visual magnitude of 5.80, making them visible by the naked eye as a single star. They also have a combined spectral classification B8V. The pair is located at approximately 800 light years from Solar System, and orbit each other with a period of 351.22 years, a separation of 0.41″, and an orbital eccentricity of 0.39. They have individual apparent magnitudes of 6.08 and 7.38, respectively.

HD 4778, also known as HR 234 and GO Andromedae, is a variable star in the constellation Andromeda. Its magnitude varies by 0.04 magnitudes from the median of 6.12 with a period of approximately 2.55 days. The star is located 350 light years away, as determined from its annual parallax shift of 9.32 mas.

ET Andromedae Star in the constellation Andromeda

ET Andromedae is a binary star system star in the northern constellation of Andromeda. It has an apparent visual magnitude of 6.48, placing it at the nominal limit for visibility with the naked eye. The distance to this system can be estimated from its annual parallax shift of 5.42 mas, which yields a value of 602 light years.

67 Aquarii is a star located 484 light years away from the Sun in the zodiac constellation of Aquarius. 67 Aquarii is its Flamsteed designation. It is a dim, blue-white hued star near the lower limit of visibility to the naked eye with an apparent visual magnitude of 6.40. At the distance of this star, its visual magnitude is diminished by an extinction of 0.11 due to interstellar dust. The position of this star near the ecliptic means it is subject to lunar eclipses.

17 Eridani is a single star in the equatorial constellation of Eridanus. It has the Bayer designation v Eridani, while 17 Eridani is the Flamsteed designation. This object is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.74. It is moving further from the Earth with a heliocentric radial velocity of around +15 km/s.

Psi Eridani, Latinized from ψ Eridani, is a star in the constellation Eridanus. With an apparent visual magnitude is 4.81, it can be seen with the naked eye on a clear, dark night. Based upon an annual parallax shift of 4.41 milliarcseconds, it is located roughly 740 light years away from the Sun.

HD 3322 is a binary star system in the northern constellation of Andromeda. With an apparent visual magnitude of 6.51, it lies below the nominal brightness limit for visibility with the normal naked eye, but it is still possible to see the star with excellent vision under ideal seeing conditions. An annual parallax shift of 4.59±0.65 mas provides a distance estimate of roughly 700 light years.

HD 34989 Blue-white star in the constellation Orion

HD 34989 is a blue-white star in the main sequence, of apparent magnitude 5.80, in the constellation of Orion. It is 1700 light-years from the solar system.

GR Andromedae Star in the constellation Andromeda

GR Andromedae is a variable star in the constellation Andromeda. Its apparent visual magnitude varies between 6.87 and 6.95 in a cycle of 518.2 days. It is classified as an α2 Canum Venaticorum variable.

References

  1. ↑ Hildebrandt, G (1975). "Lichtelektrische Untersuchungen der vier Ap-Sterne HD 9531, HD 10221 HD 27309 und HD 184905". Astronomische Nachrichten. 295 (6): 277–280. Bibcode:1975AN....296..277H. doi:10.1002/asna.19752960605.
  2. 1 2 3 4 5 6 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 .
  3. 1 2 3 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.
  4. 1 2 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.
  5. ↑ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv: 1606.08053 , Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID   119231169.
  6. 1 2 3 4 5 6 7 North, P. (June 1998), "Do SI stars undergo any rotational braking?", Astronomy and Astrophysics, 334: 181–187, arXiv: astro-ph/9802286 , Bibcode:1998A&A...334..181N
  7. 1 2 Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv: 1201.2052 , Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID   55586789, A120.
  8. 1 2 3 4 5 Huang, Wenjin; et al. (2010), "A Stellar Rotation Census of B Stars: From Zams to Tams", The Astrophysical Journal, 722 (1): 605–619, arXiv: 1008.1761 , Bibcode:2010ApJ...722..605H, doi:10.1088/0004-637X/722/1/605, S2CID   118532653.
  9. 1 2 3 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.
  10. ↑ "KK And". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved October 18, 2018.
  11. ↑ Watson, Christopher (4 January 2010). "KK Andromedae". AAVSO Website. American Association of Variable Star Observers . Retrieved 1 November 2014.
  12. ↑ Renson, P.; Manfroid, J. (2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics, 498 (3): 961, Bibcode:2009A&A...498..961R, doi: 10.1051/0004-6361/200810788 .
  13. ↑ Hric, Ladislav (July 1990), "The new helium-weak star HR 446", Astrophysics and Space Science, 169 (1–2): 177–181, Bibcode:1990Ap&SS.169..177H, doi:10.1007/BF00640707, S2CID   121899128.

Coordinates: Jupiter and moon.png 01h 34m 16.6065s, +37° 14′ 13.727″

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.