Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Microscopium |
Right ascension | 20h 40m 19.82792s [1] |
Declination | −33° 25′ 54.6462″ [1] |
Apparent magnitude (V) | 5.47±0.01 [2] |
Characteristics | |
Evolutionary stage | red giant branch [3] |
Spectral type | K1 III [4] |
U−B color index | +1.08 [5] |
B−V color index | +1.12 [5] |
Astrometry | |
Radial velocity (Rv) | 14.2±2.8 [6] km/s |
Proper motion (μ) | RA: +21.953 mas/yr [1] Dec.: +34.487 mas/yr [1] |
Parallax (π) | 13.5581±0.0691 mas [1] |
Distance | 241 ± 1 ly (73.8 ± 0.4 pc) |
Absolute magnitude (MV) | +1.17 [7] |
Details | |
Mass | 1.4±0.1 [8] M☉ |
Radius | 11.5 [9] R☉ |
Luminosity | 43.7+3.1 −2.9 [10] L☉ |
Surface gravity (log g) | 2.46±0.34 [11] cgs |
Temperature | 4,681±122 [12] K |
Metallicity [Fe/H] | −0.02 [13] dex |
Rotational velocity (v sin i) | <1 [14] km/s |
Age | 3.4±0.6 [8] Gyr |
Other designations | |
13 G. Microscopii [15] , CD−33°15119, CPD−33°5922, FK5 1540, GC 28776, HD 196737, HIP 102014, HR 7893, SAO 212333 [16] | |
Database references | |
SIMBAD | data |
HD 196737, also designated as HR 7893, is a solitary orange hued star [17] located in the southern constellation Microscopium. It has an apparent magnitude of 5.47, [2] allowing it to be faintly visible to the naked eye. The object is located relatively close at a distance of 241 light years based on Gaia DR3 parallax measurements, [1] but is receding with a heliocentric radial velocity of 14.2 km/s . [6] At its current distance, HD 196737's brightness is diminished by 0.14 magnitudes due to interstellar dust. [18] It has an absolute magnitude of 1.17. [7]
This is an evolved giant star with a stellar classification of K1 III. [4] HD 196737 is estimated to be 3.4 billion years old based on asteroseismologic measurements, [8] enough for it to cool and expand onto the red giant branch; it is now fusing a hydrogen shell around an inert helium core. [3] It has 1.4 time the mass of the Sun [8] and an enlarged radius of 11.5 R☉. [9] It radiates 43.7 times the luminosity of the Sun [10] from its photosphere at an effective temperature of 4,681 K . [12] HD 196737 has a solar metallicity — what astronomers dub chemical elements heavier than helium. The star has a projected rotational velocity too low to be measured accurately. [14]