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]

  1. ^ a b c d Cite error: The named reference EDR3 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference David2015 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference A.P1999 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Hoffleit1953 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Evans1966 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Abt1995 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Eggen1995 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Mason2001 was invoked but never defined (see the help page).