HD 121439

HD 121439
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Apus
Right ascension 14h 00m 32.81143s[1]
Declination −78° 35′ 23.9308″[1]
Apparent magnitude (V) 6.08±0.01[2]
Characteristics
Spectral type B9 III[3]
U−B color index −0.17[4]
B−V color index +0.03[4]
Astrometry
Radial velocity (Rv)4±4.7[5] km/s
Proper motion (μ) RA: −14.337 mas/yr[1]
Dec.: −9.094 mas/yr[1]
Parallax (π)4.2166 ± 0.0425 mas[1]
Distance774 ± 8 ly
(237 ± 2 pc)
Absolute magnitude (MV)−0.80[6]
Details
Mass3.26[7] M☉
Radius5.55[8] R☉
Luminosity168[9] L☉
Surface gravity (log g)3.48[7] cgs
Temperature9,708±124[10] K
Metallicity [Fe/H]+0.22[7] dex
Other designations
3 G. Apodis[11], CD−77°626, CPD−77°922, FK5 3111, GC 18877, HD 121439, HIP 68431, HR 5240, SAO 257107[12]
Database references
SIMBADdata

HD 121439, also known as HR 5240, is a solitary, bluish-white hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.08,[2] allowing it to be faintly visible to the naked eye. The object is located relatively far at a distance of 774 light years[1] based on Gaia DR3 parallax measurements but is receding with a fairly constrained radial velocity of 4 km/s.[5] At its current distance, HD 121439's brightness is diminished by 0.57 magnitudes due to interstellar dust.[13]

This is an evolved giant star with a stellar classification of B9 III.[3] It has 3.26 times the mass of the Sun[7] but has expanded to 5.6 times its girth.[8] It radiates 168 times the luminosity of the Sun[9] from its photosphere at an effective temperature of 9,708 K.[10] Based on extinction from the Gaia passband, HD 121439 has an iron abundance 1.65 times that of the Sun.[7] This makes the object metal enriched.

  1. ^ a b c d e 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 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 Anders2022 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Kervella2021 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Stassun2019 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).