25 Orionis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 24m 44.82738s[1] |
| Declination | +01° 50′ 47.2019″[1] |
| Apparent magnitude (V) | 4.92 - 4.96[2] |
| Characteristics | |
| Spectral type | B1Vn[3] |
| U−B color index | −0.92[4] |
| B−V color index | −0.20[4] |
| Variable type | γ Cas[2] |
| Astrometry | |
| Radial velocity (Rv) | 19.3 ± 2[5] km/s |
| Proper motion (μ) | RA: +1.047[1] mas/yr Dec.: +0.433[1] mas/yr |
| Parallax (π) | 2.9321±0.1219 mas[1] |
| Distance | 1,110 ± 50 ly (340 ± 10 pc) |
| Details | |
| Mass | 10.5[6] M☉ |
| Radius | 6.4[7] R☉ |
| Luminosity | 10,500[6] L☉ |
| Surface gravity (log g) | 4.0[7] cgs |
| Temperature | 24,661 ± 339[7] K |
| Rotational velocity (v sin i) | 316[8] km/s |
| Age | ~100[6] Myr |
| Other designations | |
| ψ1 Ori, 25 Ori, V1086 Ori, BD+01 1005, FK5 2406, HD 35439, HIP 25302, HR 1789, SAO 112734, CCDM J05247+0150A[3] | |
| Database references | |
| SIMBAD | data |
25 Orionis, less commonly known by its Bayer designation Psi1 Orionis (ψ1 Orionis, ψ1 Ori) is a fifth-magnitude star in the constellation Orion. It lies among a dense cluster of low-mass pre-main-sequence stars in the Orion OB1a.
Stellar group
[edit | edit source]25 Orionis is the dominant member of a rich low-mass star region,[9] first identified in 2005 in a statistical analysis of 2.5 million stars.[10] It is one of several sub-associations within Orion OB1a, all thought to lie at around the same distance of 338 parsecs. Over 200 members of the 25 Orionis stellar group have been found, mostly T Tauri stars with spectral types of K and M and masses less than half the sun's. There are also around 60 hotter stars in the region, including the eruptive variable V346 Tauri.[11] This region is known as Briceño 1.
Properties
[edit | edit source]
Like the star Pleione in the Pleiades open cluster, 25 Ori is a Be star with a gaseous circumstellar disk. The SIMBAD astronomical database lists its spectral class as B1Vn.[3]
25 Orionis is a fast rotator, clocking a rotational velocity of 316 km/s, significantly faster than Achernar's speed of 251 km/s in the constellation Eridanus.[8][13] Having a radius of 6 R☉, the star rotates on its axis roughly once every 23 hours. With a mass in excess of 10 M☉, the star is expected to explode as a supernova.[6]
25 Orionis is a Gamma Cassiopeiae variable star, and has been given the variable star designation V1086 Orionis. The General Catalog of Variable Stars lists its magnitude as varying between magnitude 4.92 and 4.96 in the visual (V) band - an amplitude only 0.04 magnitudes.[2] However photometry by the Hipparcos satellite, which had a passband broader than the V band, showed a 0.145 magnitude range in brightness.[14][15]
See also
[edit | edit source]References
[edit | edit source]- ^ a b c d e 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 Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c 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).
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c 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).
- ^ 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).
External links
[edit | edit source]- Jim Kaler's Stars, University of Illinois: 25 ORI (25 Orionis)
- Philippe Stee's in-depth information on: Hot and Active Stars Research
- Olivier Thizy's in-depth information on: Be Stars
