Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Andromeda |
Right ascension | 00h 50m 18.26563s[2] |
Declination | +45° 00′ 08.1439″[2] |
Apparent magnitude (V) | 6.13[3] |
Characteristics | |
Spectral type | A3VpSiSrCrEuKsn[4] |
B−V color index | 0.043±0.004[3] |
Variable type | α2 CVn[5] |
Astrometry | |
Radial velocity (Rv) | 1.60[6] km/s |
Proper motion (μ) | RA: 65.353[2] mas/yr Dec.: 4.133[2] mas/yr |
Parallax (π) | 9.3224 ± 0.0916 mas[2] |
Distance | 350 ± 3 ly (107 ± 1 pc) |
Absolute magnitude (MV) | 1.18[7] |
Details | |
Mass | 2.24±0.09[7] M☉ |
Radius | 2.36±0.12[8] R☉ |
Luminosity | 34.9±4.3[8] L☉ |
Surface gravity (log g) | 4.12±0.09[7] cgs |
Temperature | 9,135±400[8] K |
Rotation | 2.5616[7] days |
Rotational velocity (v sin i) | 33[4] km/s |
Age | 77[9] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 4778, also known as HR 234 and GO Andromedae, is a variable star in the constellation Andromeda. Its magnitude varies by 0.04 magnitudes from the median of 6.12 with a period of approximately 2.55 days.[11] The star is located 350 light years away, as determined from its annual parallax shift of 9.32 mas.[2]
This is an Ap star with a stellar classification of A3VpSiSrCrEuKsn,[4] showing chemical peculiarities in its spectrum from strontium, chromium, and europium.[12] It is an Alpha2 Canum Venaticorum variable[5] with a magnetic field that varies across the range +1,400 to −1,100 G.[13] This rotation-modulated variability allows direct determination of the rotation rate of 2.5616 days.[7]
HD 4778 has 2.24[7] times the mass of the Sun and 2.36[8] times the Sun's radius. The star is radiating 35[8] times the Sun's luminosity from its photosphere at an effective temperature of 9,375 K.[7] It is about 77[9] million years old.
MAST
was invoked but never defined (see the help page).GaiaDR2
was invoked but never defined (see the help page).Anderson2012
was invoked but never defined (see the help page).abt1995
was invoked but never defined (see the help page).Samus2017
was invoked but never defined (see the help page).Kharchenko
was invoked but never defined (see the help page).aaa334_181
was invoked but never defined (see the help page).Perraut_et_al_2020
was invoked but never defined (see the help page).David2015
was invoked but never defined (see the help page).SIMBAD
was invoked but never defined (see the help page).AAVSO
was invoked but never defined (see the help page).Panek1980
was invoked but never defined (see the help page).Bohlender1989
was invoked but never defined (see the help page).