We obtain flux ratios of hydrogen lines for these stars, finding that they have optically thin envelopes, except by 66 Oph and θ CrB, which do not show evidence of a circumstellar disk. γ Cas and ϕ ...

Tucked away in a star-forming region in the Taurus constellation, a pair of circling stars are displaying some unexpected differences in the circumstellar disks of dust and gas that surround them.

Over the past 20 years, astronomers have been studying a massive, 100 billion-mile-wide (161 billion kilometers) circumstellar disk of dust and gas surrounding Vega, similar to the protoplanetary ...