11 Lacertae

Coordinates: Sky map 22h 40m 30.78s, +44° 16′ 34.6″
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11 Lacertae

11 Lacertae in optical light
Observation data
Epoch J2000      Equinox J2000
Constellation Lacerta[1]
Right ascension 22h 40m 30.85881s[2]
Declination +44° 16′ 34.7042″[2]
Apparent magnitude (V) 4.46[3]
Characteristics
Spectral type K2.5 III[4]
U−B color index +1.36[3]
B−V color index +1.33[3]
Astrometry
Radial velocity (Rv)−10.91±0.09[5] km/s
Proper motion (μ) RA: +94.426[2] mas/yr
Dec.: +11.606[2] mas/yr
Parallax (π)9.80 ± 0.26 mas[2]
Distance333 ± 9 ly
(102 ± 3 pc)
Absolute magnitude (MV)−0.54[6]
Details[7]
Mass1.38 M
Radius27.70 R
Luminosity204 L
Surface gravity (log g)1.93[8] cgs
Temperature4,352[8] K
Metallicity [Fe/H]−0.19[8] dex
Rotational velocity (v sin i)8[9] km/s
Age3.2 Gyr
Other designations
11 Lac, BD+43° 4266, HD 214868, HIP 111944, HR 8632, SAO 52251[10]
Database references
SIMBADdata

11 Lacertae is a star in the northern constellation of Lacerta. It is visible to the naked eye as a faint orange-hued star with an apparent visual magnitude of 4.46.[3] It lies at a distance of about 333[2] light years and has an absolute magnitude -0.54.[6] The object is moving closer to the Earth with a heliocentric radial velocity of −10.9 km/s.[5]

This is an evolved giant star with a stellar classification of K2.5 III.[4] It is a red clump giant, meaning it is fusing helium in its core after passing through the red giant branch.[7] The star is 3.2 billion years old with 1.38 times the mass of the Sun and has expanded to 27.7 times the Sun's radius.[7] It is radiating 204[7] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,352 K.[8]

References[edit]

  1. ^ Roman, N. G. (1987). "Identification of a Constellation from a Position". Retrieved 2006-12-26.
  2. ^ a b c d e f Van Leeuwen, F. (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. ^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  4. ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  5. ^ a b Famaey, B.; et al. (2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430: 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.
  6. ^ a b Anderson, E.; Francis, Ch.; Niedzielski, A. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  7. ^ a b c d Adamczyk, M.; Deka-Szymankiewicz, B.; Niedzielski, A. (2016). "Masses and luminosities for 342 stars from the PennState-Toruń Centre for Astronomy Planet Search". Astronomy and Astrophysics. 587: A119. arXiv:1510.07495. Bibcode:2016A&A...587A.119A. doi:10.1051/0004-6361/201526628. S2CID 119299522.
  8. ^ a b c d Maldonado, J.; Villaver, E.; Niedzielski, A. (2016). "Evolved stars and the origin of abundance trends in planet hosts". Astronomy and Astrophysics. 588: A98. arXiv:1602.00835. Bibcode:2016A&A...588A..98M. doi:10.1051/0004-6361/201527883. S2CID 119212009.
  9. ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1): 1. Bibcode:1970CoAsi.239....1B.
  10. ^ "11 Lac". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-02-01.