noaoann10014 — Announcement
Thor’s Helmet: an interstellar bubble
8 June 2010
The central star is HD 56925, a massive Wolf-Rayet star nearing the end of its lifetime, which is responsible for the wind sweeping through the surrounding molecular cloud. Also listed as NGC 2359, this image was obtained at CTIO by the PROMPT consortium. When not chasing gamma-ray bursts, PROMPT serves a wide variety of users, including Star Shadows Remote Observatory (SSRO), a group of astrophotographers. This image was captured using broadband and narrowband filters: the blue-green color is oxygen emission.