UX Orionis
Variable star in the constellation Orion
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UX Orionis is a variable star in the constellation of Orion. It is a Herbig Ae star, located about 1,000 light-years from Earth.[7] At its brightest it is a magnitude 9.4 object, so it is too faint to be seen with the naked eye.[3] UX Orionis is the prototype of the UX Orionis class of variable stars (often called "UXors"), which are young stellar objects that exhibit large (greater than 2.8 magnitude), irregular changes in visual-band brightness.[3][8] UX Orionis was discovered by Henrietta Swan Leavitt.[3]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 04m 29.9879s[2] |
| Declination | −03° 47′ 14.287″[2] |
| Apparent magnitude (V) | 9.4 – 12.7[3] |
| Characteristics | |
| Spectral type | A3ea[3] |
| Variable type | UX Ori[3] |
| Astrometry | |
| Proper motion (μ) | RA: 1.056±0.028 mas/yr[2] Dec.: -3.998±0.019 mas/yr[2] |
| Parallax (π) | 3.1004±0.0285 mas[2] |
| Distance | 1,052 ± 10 ly (323 ± 3 pc) |
| Details | |
| Mass | 1.91+0.04 −0.00[4] M☉ |
| Radius | 1.7[4][a] R☉ |
| Luminosity | 13.2+5.0 −4.9[4] L☉ |
| Surface gravity (log g) | 3.75±0.12[4] cgs |
| Temperature | 8,500±250[4] K |
| Rotational velocity (v sin i) | 143[5] km/s |
| Age | 9.84+0.17 −0.00[4] Myr |
| Other designations | |
| HD 293782, HIP 23602, GSC 04758-00134, 2MASS J05042998-0347142, Gaia DR3 3212878018378138752[6] | |
| Database references | |
| SIMBAD | data |
UX Orionis is surrounded by a circumstellar disk, and the star's photometric variability appears to be caused by episodes during which the star is obscured by dusty material within the circumstellar disk.[7]
Notes
- Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
