HD 95109
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 57m 48.18690s[1] |
| Declination | −59° 43′ 55.8872″[1] |
| Apparent magnitude (V) | 5.72 - 6.90[2] |
| Characteristics | |
| Evolutionary stage | Yellow supergiant |
| Spectral type | F6-G7 Iab[2] |
| Variable type | δ Cep[2] |
| Astrometry | |
| Proper motion (μ) | RA: −5.963 mas/yr[3] Dec.: +2.397 mas/yr[3] |
| Parallax (π) | 0.553±0.0226 mas[3] |
| Distance | 6,187±218 ly (1898±67 pc)[4] |
| Absolute magnitude (MV) | −5.27[5] |
| Details | |
| Mass | 7.5 - 11.7[6] M☉ |
| Radius | 187±5[4] R☉ |
| Luminosity | 26,642±1,584[4] L☉ |
| Surface gravity (log g) | 1.2[7] cgs |
| Temperature | 5,397[4] – 5,980[7] K |
| Metallicity | +0.01[8] |
| Age | 29[8] Myr |
| Other designations | |
| U Car, CD−59°3448, HD 95109, HR 4276, HIP 52589 | |
| Database references | |
| SIMBAD | data |
HD 95109 (U Carinae) is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude is 6.86.
U Car is a δ Cepheid variable with a period of 38.7681 days. Isaac Roberts discovered that the star's brightness varies in 1891,[10] and it was one of the earliest Cepheids to be discovered. It has also one of the longest periods, and hence is one of the most luminous in the class.[11] There are still only a few Cepheids with longer periods, including RS Puppis, SV Vulpeculae, and the unusual S Vulpeculae.[2]
The brightness variation in U Car is caused by fundamental mode pulsations. The radius and temperature both vary, with the radius changing by 42 R☉ during each cycle.[12] The temperature variation causes the spectral type to vary between F6 and G7.
References
[edit | edit source]- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR3 record for this source at VizieR.
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
