MWC 349

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MWC 349

Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cygnus
Right ascension 20h 32m 45.5s
Declination +40° 39′ 36.6″
Apparent magnitude (V) 10.45
Characteristics
Spectral type Bpe
Astrometry
Proper motion (μ) RA: 35.5 mas/yr
Dec.: -15.8 mas/yr
Distance 4,560[1] ly
(1400[1] pc)
Absolute magnitude (MV) -6.7/-7.3[1]
Details
Mass 25 M
Luminosity (bolometric) 400,000/630,000[1] L
Other designations
MWC 349, V1478 Cyg, IRAS 20310+4029, 2MASS J20324553+4039366
Database references
SIMBAD data

MWC 349 is a double (likely, triple) star system in the constellation Cygnus.

Features[edit]

MWC 349 is a Be type star, where the B is the spectral type and the e denotes emission. The central star MWC 349A interacts only weakly with its partner MWC 349B about 2.4 arcsec away.

This particular star system has a number of unusual features, however, a recent study suggests the star may not be a Herbig Be star at all and instead a Luminous Blue Variable (LBV) with an absolute magnitude ranging between -6.7 and -7.3 and a bolometric luminosity badly determined, but that could be 400,000-630,000 times that of our Sun, surrounded by a circumstellar disk and a bipolar nebula with a size of up to 5 parsecs, as those found around other Luminous Blue Variable or candidates to that type of star.[1]

MWC 349 is surrounded by a protoplanetary disk of material that is being evaporated by the radiation of the central star and has the third component of the system, if exists, orbiting at a distance of 12-13 AU from the primary with a period of 9 years.[1] Emission lines of this star are those of the disk of material, not the star itself.

It is also a variable star with the designation V1478 Cyg. MWC 349A is also one of the few Be type stars with a strong radio emission. This star is also the only known example of a hydrogen recombination line maser in space. It is also the only firmly identified high-gain natural laser in the infrared recombination of hydrogen. [2]

MWC 349 may be a runaway star ejected from the nearby, massive Cygnus OB2 association. The mass of the main component of the system, MWC 349A, is assumed to have been when the star was born 40 times the mass of the Sun, but stellar evolution left it with just 20-25 solar masses, unstabilizing the system and unbounding MWC 349B.[1]

Notes[edit]

  1. ^ a b c d e f g Gvaramadze et al. (2012) A&A 541, A7
  2. ^ http://laserstars.org/news/MWC349.html

References[edit]

  1. ^ a b c d e f g Gvaramadze et al. (2012) A&A 541, A7
  2. ^ http://laserstars.org/news/MWC349.html
  • Near-infrared interferometric images of the solar system sized disk surrounding the Herbig Ae/Be star MWC 349A

Danchi W.C., Tuthill P.G. and Monnier J.D. 2001, Astrophysical Journal Letters.,

  • "Discovery of a parsec-scale bipolar nebula around MWC349A", Gvaramadze & Menton, A&A 541, A7 (2012)

External links[edit]