HD 170873

HD 170873
Location of HD 170873 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 18h 34m 31.11856s[1]
Declination −52° 53′ 29.4756″[1]
Apparent magnitude (V) 6.20±0.01[2]
Characteristics
Spectral type K2 III[3]
B−V color index +1.27[4]
Astrometry
Radial velocity (Rv)23.8±0.4[5] km/s
Proper motion (μ) RA: −16.944 mas/yr[1]
Dec.: −42.325 mas/yr[1]
Parallax (π)5.9179 ± 0.0283 mas[1]
Distance551 ± 3 ly
(169.0 ± 0.8 pc)
Absolute magnitude (MV)−0.31[6]
Details
Mass3.20±0.04[1] M☉
Radius22.6±1.2[7] R☉
Luminosity170±2[1] L☉
Surface gravity (log g)1.86[8] cgs
Temperature4,473±122[9] K
Metallicity [Fe/H]−0.01[8] dex
Rotational velocity (v sin i)<1[10] km/s
Age318+30
−31[1] Myr
Other designations
19 G. Telescopii[11], CD−52°8714, CPD−52°11158, GC 25324, HD 170873, HIP 91062, HR 6954, SAO 245559[12]
Database references
SIMBADdata

HD 170873, also known as HR 6954 or rarely 19 G. Telescopii, is a solitary orange-hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.20,[2] placing it near the limit for naked eye visibility. Gaia DR3 parallax measurements imply a distance of 551 light years[1] and it is currently receding with a heliocentric radial velocity of 23.8 km/s.[5] At its current distance, HD 170873's brightness is diminished by 0.39 magnitudes due to interstellar dust,[13] and it has an absolute magnitude of −0.31.[6]

HD 170873 is an evolved red giant with a stellar classification of K2 III.[3] It has 3.2 times the mass of the Sun but at the age of 318 million years,[1] it has expanded to 22.6 times the Sun's radius.[7] It radiates 170 times the luminosity of the Sun[1] from its enlarged photosphere at an effective temperature of 4,473 K.[9] It has a near-solar metallicity at [Fe/H] = −0.01[8] and spins too slowly for its projected rotational velocity to be measured accurately.[10]

  1. ^ a b c d e f g h i j Cite error: The named reference GaiaDR3 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. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference De Medeiros2014 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Gould1879 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 Gontcharov2017 was invoked but never defined (see the help page).