MWC 349

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

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.

While this particular star possesses a number of unusual features, a recent study suggests that it may not be a Herbig Be star at all, but rather a Luminous Blue Variable (LBV) with an absolute magnitude ranging between -6.7 and -7.3, along with a poorly understood bolometric luminosity. With a range of luminosity between 400,000-630,000 times that of the Sun, the star is surrounded by a circumstellar disk and a bipolar nebula, with a diameter of up to 5 parsecs, much like those found around other Luminous Blue Variable or candidates for that type of star.

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

This is a variable star with the designation V1478 Cyg. MWC 349A is also one of the few Be type stars with a strong radio emission. It 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.