Summary
HD 259431 (MWC 147 or V700 Monocerotis) is a young stellar object in the constellation of Monoceros.
  Credit: ESO/S. Guisard | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 06h 33m 05.19064s[1] |
| Declination | +10° 19′ 19.9826″[1] |
| Apparent magnitude (V) | 8.62 - 8.91[2] |
| Characteristics | |
| Spectral type | B6e[3] |
| U−B color index | −0.540[4] |
| B−V color index | 0.286[4] |
| Variable type | Orion[2] |
| Astrometry | |
| Radial velocity (Rv) | 19.00[5] km/s |
| Proper motion (μ) | RA: −2.410[1] mas/yr Dec.: −2.912[1] mas/yr |
| Parallax (π) | 1.5304 ± 0.0273 mas[1] |
| Distance | 2,130 ± 40 ly (650 ± 10 pc) |
| Details | |
| Mass | 6.6[6] M☉ |
| Radius | 6.63[6] R☉ |
| Luminosity | 1,550[6] L☉ |
| Temperature | 14,125[6] K |
| Rotational velocity (v sin i) | 90[7] km/s |
| Age | 0.32[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Location edit
HD 259431 lies in the northern portion of Monoceros, between Orion and Canis Minor, along with the spectacular Rosette Nebula and NGC 2264 region. It is half a degree from the faint IC 447 reflection nebula.
HD 259431 is seen against NGC 2247, a small reflection nebula and star-forming region. It has been considered to be the illuminating source for the nebula, although it is uncertain if they are at the same distance. The Hipparcos annual parallax gives a distance of 170 parsecs[8] while NGC 2247 is thought to be at about 800 parsecs, although both distances are somewhat uncertain.[9] Many of its properties have been calculated assuming a distance of 800 parsecs, which means they are also highly uncertain.[3]Gaia Data Release 3 gives a statistically precise distance around 650 parsecs.[1]
Properties edit
HD 259431 is classed as a Herbig Haro Be star and has been instrumental in helping astronomers understand the formation of stars.[6] A large star, with a large surrounding dust cloud,[7] MWC 147 has given astronomers a clear picture of the mechanics of the accretion processes that form stars.[11]
Star MWC 147 was observed in the near and mid-infrared. The near-infrared studies showed dust matter at a temperature of several thousand kelvins in the innermost regions of the protoplanetary disk. In the mid-IR were lower temperatures. These observations showed that the disk around the star disk extends over 100 AU.
The resulting research model assumes that the star increasing in mass at a rate 7×10−6 solar masses per year, or the equivalent of about two Earth masses per year. MWC has a mass of 6.6 M☉ and is younger than 500 000 years. This means that the life of this star is expected to be only about 35 million years.[citation needed]
The star is found in the night sky at RA 06 h 33 m 05.19 and Dec 10° 19' 19.9869". It has a temperature of 14 125 K and spectral type of B6ep. It is also known as 2MJ06330519 + 1019199, HD 259431, HIP 31235 and SAO 95823.
References edit
- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. eISSN 1562-6881. ISSN 1063-7729. S2CID 255195566.
- ^ a b Hernández, Jesús; Calvet, Nuria; Briceño, César; Hartmann, Lee; Berlind, Perry (2004). "Spectral Analysis and Classification of Herbig Ae/Be Stars". The Astronomical Journal. 127 (3): 1682. Bibcode:2004AJ....127.1682H. doi:10.1086/381908.
- ^ a b Kilkenny, D.; Whittet, D. C. B.; Davies, J. K.; Evans, A.; Bode, M. F.; Robson, E. I.; Banfield, R. M. (1985). "Optical and infrared photometry of southern early-type shell stars and pre-main-sequence variables". In Its South African Astronomical Observatory Circular No. 9 P 55-86 (SEE N86-18271 08-89). 9: 55. Bibcode:1985SAAOC...9...55K.
- ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ a b c d e f Kraus, Stefan; Preibisch, Thomas; Ohnaka, Keiichi (2008). "Detection of an Inner Gaseous Component in a Herbig Be Star Accretion Disk: Near- and Mid-Infrared Spectrointerferometry and Radiative Transfer modeling of MWC 147". The Astrophysical Journal. 676 (1): 490–508. arXiv:0711.4988. Bibcode:2008ApJ...676..490K. doi:10.1086/527427. S2CID 13961137.
- ^ a b Bagnoli, T.; Van Lieshout, R.; Waters, L. B. F. M.; Van Der Plas, G.; Acke, B.; Van Winckel, H.; Raskin, G.; Meerburg, P. D. (2010). "An Inner Gaseous Disk Around the Herbig Be Star MWC 147". The Astrophysical Journal Letters. 724 (1): L5–L8. arXiv:1010.1414. Bibcode:2010ApJ...724L...5B. doi:10.1088/2041-8205/724/1/L5. S2CID 119282142.
- ^ 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. S2CID 18759600. Vizier catalog entry
- ^ Lee, Chien-De; Chen, Wen-Ping; Liu, Sheng-Yuan (2016). "Evolutionary status of isolated B[e] stars". Astronomy & Astrophysics. 592: 737–753. arXiv:astro-ph/0512534. Bibcode:2016A&A...592A.130L. doi:10.1051/0004-6361/201628332. S2CID 118731419.
- ^ "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 4 December 2022.
- ^ "The Region Around MWC 147". European Space Agency. Retrieved 2016-12-24.
External links edit
- It Takes A Very Large Telescope To See Inside MWC 147