HD 130144

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HD 130144
EKBooLightCurve.png
The visual band light curve of EK Boötes, from AAVSO data [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Boötes
Right ascension 14h 46m 05.94566s [2]
Declination +15° 07 54.4332 [2]
Apparent magnitude  (V)5.78 [3] (5.33 to 5.71) [4]
Characteristics
Spectral type M5III [5]
U−B color index +1.26 [6]
B−V color index 1.335±0.021 [3]
Variable type Lb? [4]
Astrometry
Radial velocity (Rv)−22.52±0.65 [7]  km/s
Proper motion (μ)RA: −85.49 [2]   mas/yr
Dec.: +18.86 [2]   mas/yr
Parallax (π)4.04 ± 0.38  mas [2]
Distance 810 ± 80  ly
(250 ± 20  pc)
Absolute magnitude  (MV)−1.17 [3]
Details
Mass 3.1±0.5 [5]   M
Radius 210±21 [5]   R
Luminosity 521.51 [3]   L
Temperature 3,400 [5]   K
Rotational velocity (v sin i)8.5 or 11 [5]  km/s
Other designations
EK Boo, BD+15° 2758, FK5  3168, HD  130144, HIP  72208, HR  5512, SAO  101200 [8]
Database references
SIMBAD data

HD 130144 is a variable star in the northern constellation of Boötes. It has the variable star designation EK Boötis (or EK Boo), while HD 130144 is the designation from the Henry Draper Catalogue . The star is faintly visible to the naked eye with an apparent visual magnitude that ranges from 5.33 down to 5.71. [4] Parallax measurements provide a distance estimate of approximately 810  light years from the Sun. It is drifting closer with a radial velocity of −23 km/s. [7]

The brightness of HD 130144 was discovered to be variable when the Hipparcos satellite data was analyzed. It was given its variable star designation in 1999. [9] This is an aging red giant star with a stellar classification of M5III. [5] It has an estimated 3.1 times the mass of the Sun and has expanded to around 210 times the Sun's radius. [5] EK Boo is classified as a slow irregular variable that ranges in luminosity with an amplitude of 0.38 in magnitude and no apparent periodicity. This is an X-ray source, and was possibly the first M-type giant star to have a magnetic field directly detected. [10] The strength of the field ranges from –0.1 to 8  G . [11]

HD 130144 has a high rotation rate for a star of this class, which may be the result of dredge-up of angular momentum from the interior, or else a merger with an orbiting companion. [11] A long-term trend in the radial velocity data suggests this star has an orbiting companion. Most likely this is an active red dwarf that is responsible for most of the X-ray emission from the system. [10] There is nearby visual companion at an angular separation of 0.20 along a position angle of 82.2° (as of 2010). [12]

Related Research Articles

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<span class="mw-page-title-main">2 Centauri</span> Star in the constellation Centaurus

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<span class="mw-page-title-main">HD 128333</span> Star in the constellation Boötes

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<span class="mw-page-title-main">HD 93194</span> Star in the constellation Carina

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<span class="mw-page-title-main">S Boötis</span>

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References

  1. "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  2. 1 2 3 4 5 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.
  3. 1 2 3 4 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 3 Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports , 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID   125853869.
  5. 1 2 3 4 5 6 7 Konstantinova-Antova, R.; et al. (December 2010), "Direct detection of a magnetic field in the photosphere of the single M giant EK Bootis. How common is magnetic activity among M giants?", Astronomy and Astrophysics, 524: 9, arXiv: 1009.2001 , Bibcode:2010A&A...524A..57K, doi:10.1051/0004-6361/201014503, S2CID   119184105, A57.
  6. Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
  7. 1 2 Famaey, B.; et al. (2009), "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics, 498 (2): 627–640, arXiv: 0901.0934 , Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698, S2CID   18739721.
  8. "EK Boo", SIMBAD , Centre de données astronomiques de Strasbourg , retrieved 2021-04-30.
  9. Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999). "The 74th Special Name-list of Variable Stars" (PDF). Information Bulletin on Variable Stars. 4659: 1–27. Bibcode:1999IBVS.4659....1K . Retrieved 6 December 2024.
  10. 1 2 Georgiev, S.; et al. (July 2020), "Magnetism in Cool Evolved Stars: the M giants EK Bootis and β Pegasi", Bulgarian Astronomical Journal, 33: 87, Bibcode:2020BlgAJ..33...87G.
  11. 1 2 Konstantinova-Antova, Renada; Aurière, Michel; Schröder, Klaus-Peter; Petit, Pascal (April 2009), "Dynamo-generated magnetic fields in fast rotating single giants", Cosmic Magnetic Fields: From Planets, to Stars and Galaxies, Proceedings of the International Astronomical Union, IAU Symposium, vol. 259, pp. 433–434, arXiv: 0901.1537 , Bibcode:2009IAUS..259..433K, doi:10.1017/S1743921309031020, S2CID   119199670
  12. Horch, Elliott P.; et al. (February 2011), "Observations of Binary Stars with the Differential Speckle Survey Instrument. II. Hipparcos Stars Observed in 2010 January and June" (PDF), The Astronomical Journal, 141 (2): 13, Bibcode:2011AJ....141...45H, doi:10.1088/0004-6256/141/2/45, S2CID   27904496, 45.