MWC 137
Star in the constellation Canis Major
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MWC 137 is a supergiant star in the equatorial constellation of Orion. It has the variable star designation V1308 Ori; MWC 137 is from the Mount Wilson Catalogue published in 1933.[10] The star is located at a distance of about 17.0 ± 4.6 thousand light-years (5.2 ± 1.4 kpc),[6] at the center of the filamentary nebula Sh 2-266.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion[2] |
| Right ascension | 06h 18m 45.522s[3] |
| Declination | +15° 16′ 52.24″[3] |
| Apparent magnitude (V) | 11.47 to 11.62[4] |
| Characteristics | |
| Evolutionary stage | Supergiant[5] |
| Spectral type | sgB[e][6] |
| B−V color index | 1.700±0.495[2] |
| Variable type | pulsating[5] |
| Astrometry | |
| Radial velocity (Rv) | +652.92±0.02[7] km/s |
| Proper motion (μ) | RA: −0.294 mas/yr[3] Dec.: −0.510 mas/yr[3] |
| Parallax (π) | 0.194±0.0256 mas[3] |
| Distance | 17,000±4,600 ly (5,200±1,400 pc)[6] |
| Absolute magnitude (MV) | −7.2[6] |
| Details | |
| Mass | 37+9 −5 M☉[8] 30 to 70[5] M☉ |
| Radius | 26+29 −9[8] R☉ |
| Luminosity | 690,000[5] L☉ |
| Temperature | 28,200[5] K |
| Rotational velocity (v sin i) | 95.3[7] km/s |
| Age | 4.7±0.7[8] Myr |
| Other designations | |
| V1308 Ori, HIP 29988, IRAS 06158+1517, 2MASS J06184553+1516522[9] | |
| Database references | |
| SIMBAD | data |
Properties
This is a massive B[e] star that displays radial pulsational variabilities with a dominant period of around 1.9 days.[5] Evolutionary models show it to be near or in its post main sequence stage.[11] The star displays a jet – a large, collaminated outflow, which suggests the presence of an accretion disk.[6] An X-ray source detected by the SWIFT observatory may be associated with MWC 137, which suggests the presence of a neutron star companion.[12]
MWC 137 has a stellar classification of sgB[e],[6] where 'sg' indicates it is a supergiant-type B[e] star. The mass is uncertain, but lies in the range of 30 to 70 times the mass of the Sun.[5] In 2021, M. Kraus and associates found a mass estimate of roughy 37 solar masses.[8] It is radiating 690,000 times the luminosity of the Sun from its photosphere at an effective temperature of 28,200 K.[5]
This star is located at the center of the filamentary nebula Sh 2-266, which is elliptical in shape and spans an angular size of 80′ × 56′.[13] This has the form of a ring nebula, possibly as the result of stellar winds interacting with the interstellar medium or ejected matter.[14] A bow-shaped feature was discovered in 2021, at a position angle of 225°–245° at an angular separation of 80″ from MWC 137.[8] The star is directly associated with an H II region that spans an angular size of one arcminute.[15]