Free Astronomy Magazine January-February 2019

34 JANUARY-FEBRUARY 2019 SPACE CHRONICLES I C 63 — nicknamed the Ghost Nebula — is about 550 light-years from Earth. The nebula is classified as both a reflection nebula — as it is reflecting the light of a nearby star — and as an emission nebula — as it releases hy- drogen-alpha radiation. Both effects are caused by the gigantic star Gamma Cassiopeiae. The radiation of this star is also slowly causing the nebula to dissipate. [ESA/Hubble, NASA] The ghost of Cassiopeia by NASA/ESA