Nu Telescopii

ν Telescopii
Location of ν Telescopii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
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 mas/yr[1]
Dec.: −137.406 mas/yr[1]
Parallax (π)19.3152 ± 0.0783 mas[1]
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, 67 G. Telescopii, 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 L☉[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. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). 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.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
  3. ^ a b 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. Bibcode:1975mcts.book.....H.
  4. ^ a b Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  5. ^ a b 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. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. ISSN 1063-7737. S2CID 119231169.
  6. ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 119257644.
  7. ^ a b c d e 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, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  8. ^ a b 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. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
  9. ^ a b 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.
  10. ^ Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
  11. ^ a b Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. ISSN 0320-0108. S2CID 118345778.
  12. ^ "nu. Tel". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-01.{{cite web}}: CS1 maint: postscript (link)
  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. Bibcode:1879RNAO....1.....G.
  14. ^ Hoffleit, Dorrit (1953). "The spectra and absolute magnitudes of 500 A3 - G2 stars". Annals of Harvard College Observatory. 0119: 1–35. Bibcode:1953AnHar.119....1H.
  15. ^ Evans, D. S. (1966). "Fundamental data for Southern stars (6th list)". Royal Greenwich Observatory Bulletins. 110: 185. Bibcode:1966RGOB..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. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
  17. ^ Eggen, Olin J. (December 1995). "Reality Tests of Superclusters in the Young Disk Population". The Astronomical Journal. 110: 2862. Bibcode:1995AJ....110.2862E. doi:10.1086/117734. ISSN 0004-6256.
  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. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.