Young stellar object in the constellation Monoceros
HD 259431
Location of HD 259431 (circled) near the bluish IC 447 nebulosity. NGC 2264 is below (west) and the Rosette Nebula on the right (south). Credit: ESO/S. Guisard
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 Hipparcosannual 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]
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 7×10−6solar 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.
^ abKilkenny, 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.
^ abcdefKraus, 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. S2CID13961137.
^ abBagnoli, 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. S2CID119282142.