44 Boötis

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44 Boötis
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
Right ascension 15h 03m 47.29565s[1]
Declination +47° 39′ 14.6228″[1]
Apparent magnitude (V) 4.75[2] (5.136 / 6.004)[3]
Characteristics
Spectral type G0Vnv[4] + (K0V + K4V)[5]
U−B color index 0.09[2]
B−V color index 0.65[2]
Variable type W UMa
Astrometry
Radial velocity (Rv) -17.89[6] km/s
Proper motion (μ) RA: -445.84[1] mas/yr
Dec.: 19.86[1] mas/yr
Parallax (π) 78.39 ± 1.03[7] mas
Distance 41.6 ± 0.5 ly
(12.8 ± 0.2 pc)
Absolute magnitude (MV) 2.211[7]
Orbit[8]
Primary 44 Boo A
Period (P) 209.8 ± 3.3 yr
Semi-major axis (a) 3.666 ± 0.021″
Eccentricity (e) 0.5111 ± 0.0065
Inclination (i) 83.55 ± 0.05°
Longitude of the node (Ω) 57.14 ± 0.06°
Periastron epoch (T) B 2012.04 ± 0.26
Argument of periastron (ω)
(secondary)
39.86 ± 0.68°
Details
44 Boo A
Mass 1.04 ± 0.10[8] M
Luminosity 1.552[3] L
Surface gravity (log g) 4.33[9] cgs
Temperature 5,877[9] K
Metallicity [Fe/H] -0.24[9] dex
Age 1.4–1.5[10] Gyr
44 Boo B
Mass 1.28 ± 0.02[8] M
Other designations
i Boötis, i Boo, ADS 9494, CCDM 15038+4739, BD+48°2259, Gl 575, HD 133640, HIP 73695, HR 5618, SAO 45357.[11]
Database references
SIMBAD data

44 Boötis or i Boötis is a triple star system in the constellation Boötes. It is approximately 41.6 light years from Earth.

The primary component, 44 Boötis A, is a yellow-white G-type main sequence dwarf with a mean apparent magnitude of +4.83. The companion component, 44 Boötis B, is a W Ursae Majoris variable spectroscopic binary. The variability of this star system was discovered by English astronomer William Herschel.[12] The brightness of the binary varies from magnitude +5.8 to +6.40 with a period of 6.43 hours. The components of the eclipsing binary are close enough to allow their stellar envelopes to overlap, or at least nearly so.[13]

The 44 Boötis system is 42 light-years (13 parsecs) from Earth.[7] It also may show signs of an infrared excess, implying the existence of a dust disk that absorbs visible light and re-emits it as infrared light. The dust would have a blackbody temperature of about 23 K, situated up to 182 au from the parent star.[3]

References[edit]

  1. ^ a b c d van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ a b c Montesinos, B.; et al. (September 2016), "Incidence of debris discs around FGK stars in the solar neighbourhood", Astronomy & Astrophysics, 593: 31, arXiv:1605.05837Freely accessible, Bibcode:2016A&A...593A..51M, doi:10.1051/0004-6361/201628329, A51. 
  4. ^ Gray, R. O.; Napier, M. G.; Winkler, L. I. (April 2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars", The Astronomical Journal, 121 (4): 2148–2158, Bibcode:2001AJ....121.2148G, doi:10.1086/319956. 
  5. ^ Zasche, P.; Wolf, M.; Hartkopf, W. I.; Svoboda, P.; Uhlař, R.; Liakos, A.; Gazeas, K. (2009). "A Catalog of Visual Double and Multiple Stars with Eclipsing Components". The Astronomical Journal. 138 (2): 664. arXiv:0907.5172Freely accessible. Bibcode:2009AJ....138..664Z. doi:10.1088/0004-6256/138/2/664. 
  6. ^ Bilir, S.; et al. (February 2005), "Kinematics of W Ursae Majoris type binaries and evidence of the two types of formation", Monthly Notices of the Royal Astronomical Society, 357 (2): 497–517, arXiv:astro-ph/0411291Freely accessible, Bibcode:2005MNRAS.357..497B, doi:10.1111/j.1365-2966.2005.08609.x. 
  7. ^ a b c Eker, Z.; et al. (2009), "New absolute magnitude calibrations for W Ursa Majoris type binaries", Astronomische Nachrichten, 330 (1): 68–77, arXiv:0807.4989Freely accessible, Bibcode:2009AN....330...68E, doi:10.1002/asna.200811041. 
  8. ^ a b c Zirm, Henry (2011). "The Rapid Convergence of 44 Boötis with Revised Orbit and Updated Ephemerides" (PDF). Journal of Double Star Observations. 7 (1): 24–36. Bibcode:2011JDSO....7...24Z. 
  9. ^ a b c Ramírez, I.; et al. (September 2012), "Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets", The Astrophysical Journal, 756 (1): 46, arXiv:1207.0499Freely accessible, Bibcode:2012ApJ...756...46R, doi:10.1088/0004-637X/756/1/46. 
  10. ^ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686Freely accessible, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785. 
  11. ^ "i Boo -- Eclipsing binary of W UMa type (contact binary)", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2015-04-22. 
  12. ^ Percy, John R. (2007), Understanding Variable Stars, Cambridge University Press, p. 3, ISBN 1139463284. 
  13. ^ Kaler, Jim. "Asellus Tertius". Retrieved 2017-09-06. 

External links[edit]