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This article is about Lambda1 Tucanae. For other stars with this Bayer designation, see Lambda Tucanae.
Lambda1 Tucanae
Observation data
Epoch J2000.0       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  mas [1]
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  mas [3]
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
Metallicity [Fe/H]+0.04 [11]  dex
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
SIMBAD data
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. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode: 2001AJ....122.3466M, doi: 10.1086/323920.
  3. ^ a b c d e f g h i Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  4. ^ a b c Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
  5. ^ a b c Cousins, A. W. J.; Lagerweij, H. C. (1971), "UBV Observations of Variable Stars", Monthly Notes of the Astronomical Society of Southern Africa, 30: 12, Bibcode: 1971MNSSA..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, arXiv: 1208.3048, Bibcode: 2012A&A...546A..61D, doi: 10.1051/0004-6361/201219219, S2CID  59451347, A61.
  7. ^ 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.
  8. ^ a b c d e f Tokovinin, Andrei (2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv: 1401.6827, Bibcode: 2014AJ....147...87T, doi: 10.1088/0004-6256/147/4/87, S2CID  56066740, 87.
  9. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv: 1208.2037, Bibcode: 2012MNRAS.427..343M, doi: 10.1111/j.1365-2966.2012.21873.x, S2CID  118665352.
  10. ^ a b c d e f 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, arXiv: 1103.4651, Bibcode: 2011A&A...530A.138C, doi: 10.1051/0004-6361/201016276, S2CID  56118016.
  11. ^ a b 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, arXiv: 1103.4651, Bibcode: 2011A&A...530A.138C, doi: 10.1051/0004-6361/201016276, S2CID  56118016.
  12. ^ Głȩbocki, R.; Gnaciński, P. (2005). "Systematic errors in the determination of stellar rotational velocities". 13th Cambridge Workshop on Cool Stars. 560: 571. Bibcode: 2005ESASP.560..571G.
  13. ^ a b c "Lambda1 Tucanae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-11-26.
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