HD 4778
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 50m 18.26s[1] |
| Declination | +45° 00′ 08.1″[1] |
| Apparent magnitude (V) | 6.125 |
| Characteristics | |
| Spectral type | A0p |
| U−B color index | –0.03 |
| B−V color index | 0.01 |
| Variable type | α2 CVn |
| Astrometry | |
| Radial velocity (Rv) | 1.60[2] km/s |
| Proper motion (μ) | RA: 61.50 ± 0.53[1] mas/yr Dec.: 7.00 ± 0.45[1] mas/yr |
| Parallax (π) | 9.97 ± 0.68[1] mas |
| Distance | 330 ± 20 ly (100 ± 7 pc) |
| Absolute magnitude (MV) | 1.18[3] |
| Details | |
| Mass | 2.24 ± 0.09[3] M☉ |
| Radius | 2.2 ± 0.2[3] R☉ |
| Luminosity | 32[3] L☉ |
| Surface gravity (log g) | 4.12 ± 0.09[3] cgs |
| Temperature | 9,375[3] K |
| Rotation | 2.5616 days[3] |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 4778, also known as HR 234, is an Alpha2 Canum Venaticorum variable 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.[4]
References
- 1 2 3 4 5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
- ↑ Kharchenko, N. V.; Scholz, R. -D.; Piskunov, A. E.; Röser, S.; Schilbach, E. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ∼55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten 328 (9): 889. doi:10.1002/asna.200710776.
- 1 2 3 4 5 6 7 North, P. (June 1998), "Do SI stars undergo any rotational braking?", Astronomy and Astrophysics 334: 181–187, arXiv:astro-ph/9802286, Bibcode:1998A&A...334..181N
- ↑ VSX (4 January 2010). "GO Andromedae". AAVSO Website. American Association of Variable Star Observers. Retrieved 25 May 2014.
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