Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Delphinus |
Right ascension | 20h 39m 04.9681s[1] |
Declination | +15° 50′ 17.5112″[1] |
Apparent magnitude (V) | 5.98[2] |
Characteristics | |
Spectral type | B3 V[3] |
U−B color index | −0.71[2] |
B−V color index | −0.16[2] |
Astrometry | |
Radial velocity (Rv) | −4.6±1[4] km/s |
Proper motion (μ) | RA: −0.868 mas/yr[1] Dec.: −15.290 mas/yr[1] |
Parallax (π) | 3.1211 ± 0.0617 mas[1] |
Distance | 1,050 ± 20 ly (320 ± 6 pc) |
Absolute magnitude (MV) | −2.05[5] |
Details | |
Mass | 7±0.4[6] M☉ |
Radius | 4.13±0.14[7] R☉ |
Luminosity | 1,507[8] L☉ |
Surface gravity (log g) | 3.97[9] cgs |
Temperature | 18,100[9] K |
Rotational velocity (v sin i) | 145±6[10] km/s |
Age | 36.1±9.5[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 196775 (HR 7899) is a solitary star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.98, allowing it to be faintly seen with the naked eye. The object is relatively far at a distance of 1,050 light years but is approaching the Solar System with a heliocentric radial velocity of −4.6 km/s. HD 196775 has a high peculiar velocity of 21.8+1.9
−4.1 km/s[6] compared to neighboring stars, indicating that it may be a runaway star.
HD 196775 has a general stellar classification of B3 V,[3] indicating that it is an ordinary B-type main-sequence star. However, once source gives it a class of B4 Vn,[11] making it slightly cooler and having broad absorption lines due to rapid rotation. It has an angular diameter of 0.12 mas,[12] yielding a radius 4.13 times that of the Sun.[7] At present it has 7 times the mass of the Sun[6] and shines at 1507 L☉[8] from its photosphere at an effective temperature of 18,100 K,[9] giving it a whitish blue hue. HD 196775 is 36 million years old[6] and is spinning rapidly with a projected rotational velocity of 145 km/s.[10]
HD 196775 has four faint optical companions whose parameters are listed below.
Companion | mv | PA (°) | Year | Sep. (″) |
---|---|---|---|---|
B | 12.40 | 154 | 2006 | 5.2 |
C | 11.31 | 122 | 2012 | 39.9 |
D | 14.40 | 146 | 2012 | 28.8 |
E | 14.40 | 33 | 2012 | 23.3 |
EDR3
was invoked but never defined (see the help page).Oja1984
was invoked but never defined (see the help page).Cucchiaro1980
was invoked but never defined (see the help page).Gontcharov2006
was invoked but never defined (see the help page).Anderson2012
was invoked but never defined (see the help page).Tetzlaff2011
was invoked but never defined (see the help page).Lang2006
was invoked but never defined (see the help page).McDonald2012
was invoked but never defined (see the help page).Lyubimkov2004
was invoked but never defined (see the help page).Bragança2012
was invoked but never defined (see the help page).deVaucouleurs
was invoked but never defined (see the help page).Bourges2014
was invoked but never defined (see the help page).Mason2001
was invoked but never defined (see the help page).