HD 193307

HD 193307
Location of HD 193307 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
A
Right ascension 20h 21m 41.03652s[1]
Declination −49° 59′ 57.9001″[1]
Apparent magnitude (V) 6.27[2]
B
Right ascension 20h 21m 39.11678s[3]
Declination −49° 59′ 47.2058″[3]
Apparent magnitude (V) 12.8[4]
Characteristics
A
Spectral type F9 V[5]
U−B color index –0.02[2]
B−V color index +0.55[2]
B
Spectral type M2.5[6]
Astrometry
A
Radial velocity (Rv)16.9±0.65[7] km/s
Proper motion (μ) RA: −357.855 mas/yr[1]
Dec.: −250.604 mas/yr[1]
Parallax (π)32.0547 ± 0.0415 mas[1]
Distance101.7 ± 0.1 ly
(31.20 ± 0.04 pc)
Absolute magnitude (MV)+3.80[8]
B
Radial velocity (Rv)18.33±0.39[9] km/s
Proper motion (μ) RA: −350.120 mas/yr[3]
Dec.: −252.474 mas/yr[3]
Parallax (π)32.0177 ± 0.0193 mas[3]
Distance101.87 ± 0.06 ly
(31.23 ± 0.02 pc)
Details
A
Mass1.15±0.16[10] M☉
Radius1.49±0.07[11] R☉
Luminosity2.605±0.006[1] L☉
Surface gravity (log g)4.11±0.03[12] cgs
Temperature6,059+96
−59[13] K
Metallicity [Fe/H]−0.34±0.06[14] dex
Rotational velocity (v sin i)<5[15] km/s
Age7.55+0.62
−0.85[12] Gyr
Other designations
WDS J20217-5000AB[16]
A: 86 G. Telescopii[17], CD–50°12929, CPD−50°11341, FK5 3630, GC 28291, GJ 9691, HD 193307, HIP 100412, HR 7766, SAO 246546[16]
B: WT 703
Database references
SIMBADA
B

HD 193307 (HR 7766; Gliese 9691) is the primary of a binary star located the southern constellation Telescopium. It has an apparent magnitude of 6.27,[2] placing it near the limit for naked eye visibility, even under ideal conditions. The star is located relatively close at a distance of 102 light years based on Gaia DR3 parallax measurements,[1] but it is receding with a heliocentric radial velocity of 16.9 km/s.[7] At its current distance, HD 193307's brightness is diminished by 0.18 magnitudes due to extinction from interstellar dust[18] and it has an absolute magnitude of +3.80.[8] HD 193307 has a relatively high proper motion, moving at a rate of 437 mas/yr.[19]

There has been disagreements in the stellar classification of the object. Two sources give a class of F9 V,[5] indicating that it is an ordinary F-type main-sequence star. David Stanley Evans gave it a slightly more evolved class of G2 IV-V,[20] meaning that it is a G-type star with a luminosity class intermediate between a subgiant and main sequence star. Nancy Houk's spectral classification catalog lists HD 193307 as G0 V.[21]

The accepted class for HD 193307 is F9 V.[5] The object's current luminosity is 1.49 magnitudes above the ZAMS, indicating that HD 193307 is somewhat evolved.[22] has 1.15 times the Sun's mass and a slightly enlarged radius of 1.49 R☉.[11] It radiates 2.61 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 6,059 K,[13] which gives it the typical whitish-yellow hue of a late F-type star. At the age of 7.55 billion years,[12] HD 193307 has nearly twice the Sun's age. The star is metal-deficient with an iron abundance 46% that of the Sun ([Fe/H] = −0.34)[14] and it spins slowly with a projected rotational velocity lower than 5 km/s.[15]

WT 703 is a 12th magnitude star located 21.3" away along a position angle of 300°. It has a class of M2.5, indicating that it is a M-type star.[4] WT 703 is located around the same distance as HD 193307 and it has a similar proper motion.

  1. ^ a b c d e f g Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Przybylski1965 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference GaiaDR3B was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Mason2001 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Scholz2016 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Valenti2005 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference XHIP was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference GaiaDR2B was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Stassun2018 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  12. ^ a b c Cite error: The named reference Aguilera-Gómez2018 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  14. ^ a b Cite error: The named reference Ramírez2012 was invoked but never defined (see the help page).
  15. ^ a b Cite error: The named reference Groot1996 was invoked but never defined (see the help page).
  16. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Knapp2019 was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference Evans1961 was invoked but never defined (see the help page).
  21. ^ Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  22. ^ Cite error: The named reference Nordstrom2004 was invoked but never defined (see the help page).