Astronomy:Lambda1 Tucanae

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Short description: Binary star system in the constellation Tucana


Lambda1 Tucanae
Observation data
{{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000.0      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}}
Constellation Tucana
A
Right ascension  00h 52m 24.5198s[1]
Declination −69° 30′ 13.5440″[1]
Apparent magnitude (V) 6.70[2]
B
Right ascension  00h 52m 28.3487s[3]
Declination −69° 30′ 10.3819″[3]
Apparent magnitude (V) 7.35[2]
Characteristics
A
Spectral type F7 IV-V[4]
U−B color index +0.07[5]
B−V color index +0.55[5]
B
Spectral type G0/2V[4]
Astrometry
A
Radial velocity (Rv)+29.4±0.2[6] km/s
Proper motion (μ) RA: 3.849±0.050[1] mas/yr
Dec.: −67.462±0.040[1] mas/yr
Parallax (π)16.4907 ± 0.0293[1] mas
Distance197.8 ± 0.4 ly
(60.6 ± 0.1 pc)
Absolute magnitude (MV)+2.68[7]
B
Proper motion (μ) RA: 9.966±0.062[3] mas/yr
Dec.: −79.096±0.052[3] mas/yr
Parallax (π)16.5242 ± 0.0361[3] mas
Distance197.4 ± 0.4 ly
(60.5 ± 0.1 pc)
Details
A
Mass1.55[8] M
Luminosity7[9] L
Surface gravity (log g)3.90[10] cgs
Temperature6,325[10] K
Metallicity [Fe/H]+0.09[10] dex
Age2.6[10] Gyr
B
Mass1.38[8] M
Radius1.86[3] R
Luminosity3.534[3] L
Surface gravity (log g)3.94[11] cgs
Temperature5,797[3] K
Rotational velocity (v sin i)3.6[12] km/s
Other designations
DUN 2, CCDM J00524-6930AB, WDS J00524-6930AB[13]
A: λ1 Tucanae, CPD−70 37, HD 5190, HIP 4084, HR 252, SAO 248269[13]
B: CPD−70 38, HD 5208, HIP 4088, SAO 248271[13]
Database references
SIMBADdata
companion

Lambda1 Tucanae is the Bayer designation for one member of a pair of stars sharing a common proper motion through space,[8] which lie within the southern constellation of Tucana. As of 2013, the pair had an angular separation of 20.0 arc seconds along a position angle of 82°.[2] Together, they are barely visible to the naked eye with a combined apparent visual magnitude of 6.21.[5] Based upon an annual parallax shift for both stars of approximately 16.5[1][3] mas as seen from Earth, this system is located roughly 198 light years from the Sun.

The brighter member, component A, is a magnitude 6.70[2] F-type star with a stellar classification of F7 IV-V.[4] The luminosity class may indicate that, at the age of 2.6 billion years,[10] it is beginning to evolve away from the main sequence. It has an estimated 1.55[8] times the mass of the Sun and is radiating 7[9] times the solar luminosity from its photosphere at an effective temperature of 6,325 K.[10] The magnitude 7.35[2] companion, component B, has 1.38[8] times the mass of the Sun. If the pair are gravitationally bound, then their estimated orbital period is 27,000 years.[8]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode2001AJ....122.3466M. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  4. 4.0 4.1 4.2 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode1978mcts.book.....H. 
  5. 5.0 5.1 5.2 Cousins, A. W. J.; Lagerweij, H. C. (1971), "UBV Observations of Variable Stars", Monthly Notes of the Astronomical Society of Southern Africa 30: 12, Bibcode1971MNSSA..30...12C. 
  6. de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  7. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  8. 8.0 8.1 8.2 8.3 8.4 8.5 Tokovinin, Andrei (2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal 147 (4): 14, doi:10.1088/0004-6256/147/4/87, 87, Bibcode2014AJ....147...87T. 
  9. 9.0 9.1 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode2012MNRAS.427..343M. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode2011A&A...530A.138C. 
  11. Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode2011A&A...530A.138C. 
  12. Głȩbocki, R.; Gnaciński, P. (2005). "Systematic errors in the determination of stellar rotational velocities". 13th Cambridge Workshop on Cool Stars 560: 571. Bibcode2005ESASP.560..571G. 
  13. 13.0 13.1 13.2 "Lambda1 Tucanae". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Lambda1+Tucanae.