FK Comae Berenices

Last updated
FK Comae Berenices
FKComLightCurve.png
Light curves for FK Comae Berenices. The main plot shows the short term variability plotted from TESS data; [1] the inset, adapted from Panov and Dimitrov (2007), [2] shows the long term variability.
Observation data
Epoch J2000       Equinox J2000
Constellation Coma Berenices
Right ascension 13h 30m 46.79937s [3]
Declination +24° 13′ 57.7862″ [3]
Apparent magnitude  (V)8.14 – 8.33 [4]
Characteristics
Spectral type G4 III [5]
Variable type FK Com [4]
Astrometry
Radial velocity (Rv)−21.0±5.8 [5]  km/s
Proper motion (μ)RA: −51.969 [3]   mas/yr
Dec.: −22.262 [3]   mas/yr
Parallax (π)4.6102 ± 0.0446  mas [3]
Distance 707 ± 7  ly
(217 ± 2  pc)
Absolute magnitude  (MV)1.2 [6]
Details
Mass 1.1 [7]   M☉
Radius 6.99 [3]   R☉
Luminosity 26.8 [3]   L☉
Surface gravity (log g)2.359 [8]   cgs
Temperature 4,966 [3]   K
Metallicity [Fe/H]−0.89 [7]   dex
Rotation 2.4 days [9]
Rotational velocity (v sin i)160 [10]  km/s
Other designations
BD+24°2592, HD  117555, HIP  65915, SAO  82867 [11]
Database references
SIMBAD data

FK Comae Berenices is a variable star that varies in apparent magnitude between 8.14 and 8.33 over a period of 2.4 days. In 1966, Pavel Fedorovich Chugainov discovered that the star, then called HD 117555, varied in brightness. [12] It was given its variable star designation, FK Comae Berenices, in 1968. [13] It is the prototype for the FK Comae Berenices (FK Com) class of variable stars. The variability of FK Com stars may be caused by large, cool spots on the rotating surfaces of the stars. This star is thought to be the result of a recent binary merger, resulting in a high rate of both spin and magnetic activity.

The spectral class of FK Comae Berenices is G4 III, although it is considered unusual in having very broad absorption lines as well as some emission lines. The broadened spectral lines are due to rapid rotation. [10]

The rotation rate of FK Comae Berenices is unusually fast for a cool giant star. It is speculated that this is due to the merger of a contact binary pair of stars into a single star. The rotation produces extremely strong magnetic fields which are expected to brake the star to a slower rotation rate. Analysis of variability due to star spots on the surface show that the star rotates at different speeds at different latitudes. [9]

FK Comae Berenices is listed as a companion to the slightly brighter HD 117567. The two are not thought to be physically associated, with HD 117567 being a much closer F2 main sequence star. [14]

Related Research Articles

<span class="mw-page-title-main">Beta Comae Berenices</span> Star in the constellation Coma Berenices

Beta Comae Berenices is a main sequence dwarf star in the northern constellation of Coma Berenices. It is located at a distance of about 29.95 light-years from Earth. The Greek letter beta (β) usually indicates that the star has the second highest visual magnitude in the constellation. However, with an apparent visual magnitude of 4.3, this star is actually slightly brighter than α Comae Berenices. It can be seen with the naked eye, but may be too dim to be viewed from a built-up urban area.

<span class="mw-page-title-main">Iota Boötis</span> Binary star system in the northern constellation of Boötes

Iota Boötis is a member of a binary star system in the constellation Boötes, approximately 96 light-years from Earth. It has the traditional name Asellus Secundus and the Flamsteed designation 21 Boötis. The companion is HD 234121, a K0 main sequence star.

<span class="mw-page-title-main">CS Camelopardalis</span> Binary star in the constellation Camelopardalis

CS Camelopardalis is a binary star in reflection nebula VdB 14, in the constellation Camelopardalis. It is a 4th magnitude star, and is visible to the naked eye under good observing conditions.

<span class="mw-page-title-main">9 Vulpeculae</span> Star in the constellation Vulpecula

9 Vulpeculae is a star in the northern constellation of Vulpecula, located about 560 light years away based on parallax. It is visible to the naked eye as a faint, blue-white hued star with a baseline apparent visual magnitude of 5.01. The star is moving further from the Earth with a heliocentric radial velocity of +5 km/s.

<span class="mw-page-title-main">OU Andromedae</span> Rotationally variable star in the constellation Andromeda

OU Andromedae is a rotationally variable star in the constellation Andromeda. Varying between magnitudes 5.87 and 5.94, it has been classified as an FK Comae Berenices variable, but the classification is still uncertain. It has a spectral classification of G1IIIe, meaning that it is a giant star that shows emission lines in its spectrum. It is also likely in its horizontal branch phase of evolution.

<span class="mw-page-title-main">HD 155035</span> Star in the constellation Ara

HD 155035 is a star in the constellation Ara, the Altar. It is located at a distance of approximately 1,450 light-years from Earth and has an apparent visual magnitude of 5.92, making it is faintly visible to the naked eye. This is a red giant star with a stellar classification of M1.5 III.

<span class="mw-page-title-main">S Monocerotis</span> Star in the constellation Monoceros

S Monocerotis, also known as 15 Monocerotis, is a massive multiple and variable star system located in the constellation Monoceros. It is the brightest star in the Christmas Tree open cluster in the area catalogued as NGC 2264.

<span class="mw-page-title-main">V381 Cephei</span> Triple star system in the constellation Cepheus

V381 Cephei is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7. It is faintly visible to the naked eye under good observing conditions.

<span class="mw-page-title-main">1 Camelopardalis</span> Double star system in the constellation Camelopardalis

1 Camelopardalis is a double star system in the constellation Camelopardalis. Its combined apparent magnitude is 5.56 and it is approximately 800 parsecs (2,600 ly) away. It is faintly visible to the naked eye under good observing conditions.

<span class="mw-page-title-main">37 Comae Berenices</span> Triple-star system in the constellation Coma Berenices

37 Comae Berenices is a variable star system located around 690 light years away from the Sun in the northern constellation of Coma Berenices. It has the variable star designation LU Comae Berenices. 37 Comae Berenices was a later Flamsteed designation of 13 Canum Venaticorum. This object is visible to the naked eye as a faint, yellow-hued star with a baseline apparent visual magnitude of 4.88. It is drifting closer to the Earth with a heliocentric radial velocity of −14 km/s.

31 Comae Berenices is a yellow giant star in the constellation Coma Berenices. Its apparent magnitude is about 4.9 and slightly variable. It is visible to the naked eye. In 1997, Klaus G. Strassmeier et al. announced their discovery that the star is a variable star. It was given its variable star designation, LS Comae Berenices, in 2003. It is a rare FK Comae Berenices variable, a variable star that spins rapidly and has large starspots on its surface. It is currently in the Hertzsprung gap and its outer envelope has just begun convection. In 1989 it was given as a spectral standard for the class G0IIIp.

<span class="mw-page-title-main">28 Monocerotis</span> Star in the constellation Monoceros

28 Monocerotis is a single star in the equatorial constellation of Monoceros. It has an orange-hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.69. The distance to this star is approximately 450 light years based on parallax, and it has an absolute magnitude of −1.00. The star is drifting further away from the Sun with a radial velocity of +26.7 km/s.

<span class="mw-page-title-main">Sigma Ophiuchi</span> Star in the constellation Ophiuchus

Sigma Ophiuchi, Latinized from σ Ophiuchi, is a single, orange-hued star in the equatorial constellation Ophiuchus. Its apparent visual magnitude is 4.31, which is bright enough to be faintly visible to the naked eye. The annual parallax shift of 3.62 mas as seen from Earth provides a distance estimate of roughly 900 light years. It is moving closer to the Sun with a radial velocity of −28 km/s.

<span class="mw-page-title-main">21 Comae Berenices</span> Star in the constellation Coma Berenices

21 Comae Berenices is a variable star in the northern constellation of Coma Berenices. It has the variable star designation UU Comae Berenices, while 21 Comae Berenices is the Flamsteed designation.

<span class="mw-page-title-main">HD 111395</span> Star in the constellation Coma Berenices

HD 111395 is a single, variable star in the northern constellation of Coma Berenices. It has the variable star designation LW Com, short for LW Comae Berenices; HD 111395 is the Henry Draper Catalogue designation. The star has a yellow hue and is just bright enough to be barely visible to the naked eye with an apparent visual magnitude that fluctuates around 6.29. Based upon parallax measurements, it is located at a distance of 55.8 light years from the Sun. The star is drifting closer with a radial velocity of −8.9 km/s. It is a member of the Eta Chamaeleontis stellar kinematic group.

LoTr 5 is a large, faint planetary nebula in the constellation of Coma Berenices. In 2018, its parallax was measured by Gaia, giving a distance of about 1,650 light-years.

<span class="mw-page-title-main">V1794 Cygni</span> FK Comae Berenices variable in the constellation Cygnus

V1794 Cygni is a single variable star in the northern constellation Cygnus. It has the identifier HD 199178 from the Henry Draper Catalogue; V1794 Cygni is its variable star designation. With an apparent visual magnitude of 7.24, it's too dim to be visible with the naked eye but can be seen with binoculars. V1794 is located at a distance of 367 light-years (113 pc) based on parallax measurements, but is drifting closer to the Sun with a radial velocity of −31 km/s. It lies superimposed over a region of faint nebulosity to the west of the North American Nebula.

<span class="mw-page-title-main">HD 283750</span> Star in the constellation Taurus

HD 283750, also known as V833 Tauri, is a K-type main-sequence star 57 light-years away from the Sun. The star is much younger than the Sun's at 1 billion years. HD 283750 is similar to the Sun in its concentration of heavy elements.

<span class="mw-page-title-main">YY Mensae</span> Star in the constellation of Mensa

YY Mensae, also known as HD 32918, is a variable star located in the southern circumpolar constellation Mensa. It has an apparent magnitude that fluctuates between 8.6 and 8.9, which is within the visibility of binoculars. Based on parallax measurements from Gaia DR3, it is estimated to be 715 light years distant. It appears to be approaching the Solar System with a heliocentric radial velocity of −8.5 km/s.

<span class="mw-page-title-main">EK Eridani</span> Star in the constellation Eridanus

EK Eridani is a single variable star in the equatorial constellation of Eridanus. It has the designation HR 1362 from the Bright Star Catalogue; EK Eridani is the variable star designation, abbreviated EK Eri. This star is dimly visible to the naked eye with a brightness that fluctuates around 6.15. Based on parallax measurements, it is located at a distance of 209 light years from the Sun. The star is drifting further away with a heliocentric radial velocity of 6.9 km/s.

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ↑ Panov, K.; Dimitrov, D. (May 2007). "Long-term photometric study of FK Comae Berenices and HD 199178". Astronomy and Astrophysics. 467: 229–235. doi: 10.1051/0004-6361:20065596 .
  3. 1 2 3 4 5 6 7 8 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.
  4. 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)", VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S, 1: B/gcvs, Bibcode:2009yCat....102025S.
  5. 1 2 Strassmeier, Klaus G. (September 2009), "Starspots", The Astronomy and Astrophysics Review , 17 (3): 251–308, Bibcode:2009A&ARv..17..251S, doi: 10.1007/s00159-009-0020-6 .
  6. ↑ Korhonen, H.; Berdyugina, S. V.; Hackman, T.; Duemmler, R.; Ilyin, I. V.; Tuominen, I. (1999), "Study of FK Comae Berenices. I. Surface images for 1994 and 1995", Astronomy and Astrophysics , 346: 103, Bibcode:1999A&A...346..101K.
  7. 1 2 Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevič, G.; Monari, G.; Cantat-Gaudin, T.; Weiler, M.; Khan, S.; Miglio, A.; Carrillo, I.; Romero-Gómez, M.; Minchev, I.; De Jong, R. S.; Antoja, T.; Ramos, P.; Steinmetz, M.; Enke, H. (2019), "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18", Astronomy and Astrophysics, 628: A94, arXiv: 1904.11302 , Bibcode:2019A&A...628A..94A, doi:10.1051/0004-6361/201935765, S2CID   131780028.
  8. ↑ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017), "Fundamental parameters and infrared excesses of Tycho–Gaia stars", Monthly Notices of the Royal Astronomical Society, 471 (1): 770–791, arXiv: 1706.02208 , Bibcode:2017MNRAS.471..770M, doi: 10.1093/mnras/stx1433 .
  9. 1 2 Hackman, T.; Pelt, J.; Mantere, M. J.; Jetsu, L.; Korhonen, H.; Granzer, T.; Kajatkari, P.; Lehtinen, J.; Strassmeier, K. G. (2013), "Flip-flops of FK Comae Berenices", Astronomy & Astrophysics, 553: A40, arXiv: 1211.0914 , Bibcode:2013A&A...553A..40H, doi: 10.1051/0004-6361/201220690 , S2CID   118705220.
  10. 1 2 Ayres, Thomas R.; et al. (March 2016), "FK Comae Berenices, King of Spin: The COCOA-PUFS Project", The Astrophysical Journal Supplement Series , 223 (1): 30, arXiv: 1601.03305 , Bibcode:2016ApJS..223....5A, doi: 10.3847/0067-0049/223/1/5 , S2CID   118501523, 5.
  11. ↑ "FK Com". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-01-06.
  12. ↑ Chugainov, P. F. (December 1966). "New Microvariable HD 117555" (PDF). Information Bulletin on Variable Stars. 172: 1–2. Bibcode:1966IBVS..172....1C . Retrieved 28 January 2025.
  13. ↑ Kukarkin, B. V.; Efremov, Yu. N.; Frolov, M. S.; Medvedeva, G. I.; Kholopov, P. N.; Kurochkin, N. E.; Kukarkina, N. P.; Perova, N. B.; Fedorovich, V. P. (November 1968). "Identification List of the New Variable Stars Nominated in 1968" (PDF). Information Bulletin on Variable Stars. 311. Bibcode:1968IBVS..311....1K . Retrieved 28 January 2025.
  14. ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi: 10.1086/323920 .
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.