44 Boötis

From Wikipedia, the free encyclopedia
  (Redirected from 44 Bootis)
Jump to navigation Jump to search
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
Distance41.6 ± 0.5 ly
(12.8 ± 0.2 pc)
Absolute magnitude (MV)+2.211[7] / +5.38[8]
Orbit[9]
Primary44 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°
Orbit[8]
Period (P)0.267818 days
Eccentricity (e)0.0
Semi-amplitude (K1)
(primary)
231.31 km/s
Semi-amplitude (K2)
(secondary)
112.70 km/s
Details
44 Boo A
Mass1.04 ± 0.10[9] M
Luminosity1.552[3] L
Surface gravity (log g)4.33[10] cgs
Temperature5,877[10] K
Metallicity [Fe/H]-0.24[10] dex
Age1.4–1.5[11] Gyr
44 Boo B
Mass1.28 ± 0.02[9] 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.[12]
Database references
SIMBADdata

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.[13] 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.[14]

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:0708.1752, 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:1605.05837, 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:0907.5172. 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/0411291, 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:0807.4989, Bibcode:2009AN....330...68E, doi:10.1002/asna.200811041.
  8. ^ a b Lu, Wenxian; Rucinski, Slavek M; Ogłoza, Waldemar (2001). "Radial Velocity Studies of Close Binary Stars. IV". The Astronomical Journal. 122: 402. arXiv:astro-ph/0104065. Bibcode:2001AJ....122..402L. doi:10.1086/321131.
  9. ^ 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.
  10. ^ 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:1207.0499, Bibcode:2012ApJ...756...46R, doi:10.1088/0004-637X/756/1/46.
  11. ^ 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:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785.
  12. ^ "* i Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-04-22.
  13. ^ Percy, John R. (2007), Understanding Variable Stars, Cambridge University Press, p. 3, ISBN 1139463284.
  14. ^ Kaler, Jim. "Asellus Tertius". Retrieved 2017-09-06.

External links[edit]