HD 170069

HD 170069
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 18h 29m 55.9414s[1]
Declination −47° 13′ 13.9500″[1]
Apparent magnitude (V) 5.68±0.01[2]
Characteristics
Spectral type K2 III[3]
B−V color index +1.26[4]
Astrometry
Radial velocity (Rv)−18±4.3[5] km/s
Proper motion (μ) RA: +28.685 mas/yr[1]
Dec.: −12.434 mas/yr[1]
Parallax (π)5.5748 ± 0.1894 mas[1]
Distance590 ± 20 ly
(179 ± 6 pc)
Absolute magnitude (MV)−0.78[6]
Details
Mass4.08[7] M☉
Radius23.69[8] R☉
Luminosity217[9] L☉
Surface gravity (log g)1.46[10] cgs
Temperature4490±125[8] K
Rotational velocity (v sin i)<1[11] km/s
Other designations
15 G. Telescopii, CD−47°12319, CPD−47°8894, GC 25216, HD 170069, HIP 90662, HR 6922, SAO 229064[12][13]
Database references
SIMBADdata

HD 170069 (HR 6922) is a solitary[14] star in the southern constellation Telescopium. It has an apparent magnitude of 5.68,[2] allowing it to be faintly seen with the naked eye. The star is located at a distance of 590 light years[1] but is approaching closer with a heliocentric radial velocity of −18 km/s.[5] HD 170069 was designated as Tau Telescopii (τ Telescopii) before Benjamin Apthorp Gould dropped the title.[15]

HD 170069 has a stellar classification of K2 III,[3] indicating that it is a red giant. It has 4.08 times the mass of the Sun[7] but has expanded to 23.69 times its girth.[8] It radiates at 217 times the luminosity of the Sun[9] from its enlarged photosphere at an effective temperature of 4,490 K,[8] giving an orange hue. Due to its evolved state, it has a projected rotational velocity that is less than 1 km/s.[11]

  1. ^ a b c d e Cite error: The named reference EDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Corben1971 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 Cite error: The named reference Kervella2021 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Stassun2019 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 McDonald2017 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference DeMed2014 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 Eggleton2008 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Wagman2003 was invoked but never defined (see the help page).