astrobites | 2017 Feb 06
Matthew Green wrote:
What happens if a star spins so fast it throws off its own atmosphere?
We believe this is what we see in a class of stars called Be stars. Be stars are stars of spectral class B whose spectra also show emission lines, often double-peaked ... This shape of emission line can be matched by a model in which the star is surrounded by a disc of material, with the emission coming from the disc rather than the star itself. One side of the disc is moving towards us relative to the star, and its emission is therefore Doppler shifted towards the blue end of the spectrum (‘blue-shifted’). The other side is moving away from us relative to the star, causing its light to be red-shifted. The result is that see two peaks with different wavelengths, each peak corresponding to one side of the disc. ...
A Spectroscopic Orbit for the late-type Be star β CMi - Nick Dulaney et al
- arXiv.org > astro-ph > arXiv:1701.05201 > 18 Jan 2017