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] |
Distance | 101.7 ± 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] |
Distance | 101.87 ± 0.06 ly (31.23 ± 0.02 pc) |
Details | |
A | |
Mass | 1.15±0.16[10] M☉ |
Radius | 1.49±0.07[11] R☉ |
Luminosity | 2.605±0.006[1] L☉ |
Surface gravity (log g) | 4.11±0.03[12] cgs |
Temperature | 6,059+96 −59[13] K |
Metallicity [Fe/H] | −0.34±0.06[14] dex |
Rotational velocity (v sin i) | <5[15] km/s |
Age | 7.55+0.62 −0.85[12] Gyr |
Other designations | |
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 | |
SIMBAD | A |
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.
GaiaDR3
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