MWC 656

[1] At one time it was considered a member of the Lacerta OB1 association of co-moving stars,[4] but the distance estimate places it well past that group.

Spectra from the star showed evidence of emission from a circumstellar disk, as well as absorption from a shell feature.

Hipparcos light curve data indicated an orbital period of 60.37±0.04 d.[10] This was confirmed in 2012 via radial velocity measurements of helium lines in photosphere of the Be star.

[15] Refined radial velocity measurements in 2014 indicated a massive companion in the range of 3.8–6.9 M☉, assuming the Be star has a mass of 10–16 M☉.

Likewise, a subdwarf or a stripped helium core from a massive progenitor star don't fit the observations.

The 2022 discovery of tidal distortion of the disk orbiting the Be star invalidated the original radial velocity amplitude, which called into question the 2014 mass estimates.

A light curve for MWC 656. The blue points show the Hipparcos data. [ 14 ] The red curve shows a sine function fit to that data, and the green points show the averages of the data within 10 bins across each period.