Astronomy:Nu Telescopii

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Short description: High proper motion star
ν Telescopii
Telescopium IAU.svg
Red circle.svg
Location of ν Telescopii (circled)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Telescopium
Right ascension  19h 48m 01.1977s[1]
Declination −56° 21′ 45.3996″[1]
Apparent magnitude (V) 5.33±0.01[2]
Characteristics
Spectral type A7 III/IV[3]
B−V color index +0.20[4]
Astrometry
Radial velocity (Rv)−12.4±4.2[5] km/s
Proper motion (μ) RA: +90.983[1] mas/yr
Dec.: −137.406[1] mas/yr
Parallax (π)19.3152 ± 0.0783[1] mas
Distance168.9 ± 0.7 ly
(51.8 ± 0.2 pc)
Absolute magnitude (MV)+1.86[6]
Details
Mass1.85[7] M
Radius1.94±0.09[8] R
Luminosity15.6±0.1[9] L
Surface gravity (log g)4.08+0.08−0.07[10] cgs
Temperature8,199±279[7] K
Metallicity [Fe/H]−0.02[11] dex
Age686[7] Myr
Other designations
ν Tel, CPD−56° 9290, FK5 739, HD 186543, HIP 97421, HR 7510, SAO 246271[12][13]
Database references
SIMBADdata

Nu Telescopii, Latinized from ν Telescopii, is a slightly evolved star in the southern constellation Telescopium. It has an apparent visual magnitude of 5.33,[4] allowing it to be faintly visible to the naked eye. The object is relatively close at a distance of 169 light years but is approaching the Solar System with a heliocentric radial velocity of about −12 km/s.[5]

There hasn't been much agreement on Nu Telescopii's spectral classification. It was initially categorized as Am star, with a classification of kA4mF3IV:[14] . This indicates that the object has the calcium K-lines of an A4 star and the metallic lines of a F3 subgiant. However, Nu Telescopii was shown not to have a peculiar spectrum and was given a class of A9 Vn,[15] indicating that it is an A-type main-sequence star displaying broad (nebulous) absorption lines due to rapid rotation. It has since been classified as an evolved A7 star with either a blended luminosity class of a giant star or subgiant (III/IV)[3] or only subgiant (IV).[16]

Nu Telescopii has a mass of 1.85 M and an age of 686 million years.[7] It has 1.94 times the radius of the Sun[8] and has an effective temperature of 8,199 K.[7] These parameters yield a luminosity of 15.6 solar luminosity[9] from its photosphere and when viewed, has a white hue. Nu Telescopii's metallicity – what astronomers dub as elements heavier than helium – is around solar level.[11] Its motion in space matches that of the IC 2391 cluster, making it a probable member. [17]

There is a faint magnitude 9.3 companion star at an angular separation of 102 arc seconds along a position angle of 333°, as of 2010.[18]

References

  1. 1.0 1.1 1.2 1.3 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  2. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0.. Bibcode1975mcts.book.....H. 
  4. 4.0 4.1 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  5. 5.0 5.1 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. ISSN 1063-7737. Bibcode2006AstL...32..759G. 
  6. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation" (in en). Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 7.3 7.4 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode2015ApJ...804..146D. 
  8. 8.0 8.1 Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. ISSN 0004-6361. Bibcode1999A&A...352..555A. 
  9. 9.0 9.1 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.
  10. Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Bibcode2019AJ....158..138S. 
  11. 11.0 11.1 Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771–782. doi:10.1134/S1063773712120031. ISSN 0320-0108. Bibcode2012AstL...38..771G. 
  12. "nu. Tel". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=nu.+Tel. 
  13. Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino 1. Bibcode1879RNAO....1.....G. 
  14. Hoffleit, Dorrit (1953). "The spectra and absolute magnitudes of 500 A3 - G2 stars". Annals of Harvard College Observatory 0119: 1–35. Bibcode1953AnHar.119....1H. 
  15. Evans, D. S. (1966). "Fundamental data for Southern stars (6th list).". Royal Greenwich Observatory Bulletins 110: 185. Bibcode1966RGOB..110..185E. 
  16. Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series 99: 135. doi:10.1086/192182. ISSN 0067-0049. Bibcode1995ApJS...99..135A. 
  17. Eggen, Olin J. (December 1995). "Reality Tests of Superclusters in the Young Disk Population". The Astronomical Journal 110: 2862. doi:10.1086/117734. ISSN 0004-6256. Bibcode1995AJ....110.2862E. 
  18. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal 122 (6): 3466–3471. doi:10.1086/323920. ISSN 0004-6256. Bibcode2001AJ....122.3466M.