Abell21 Medusa Nebula


Mark Griffith


Teleskop service 12″ Richey-Chretien telescope, Skywatcher EQ8 mount,Atik 383L+ camera, Astronomik Sii, Ha, Oiii filters.

Ancient planetary nebula in the constellation of Gemini. A dying star throwing off clouds off gas.

Not listed on the NGC or IC catalogues. Surprising given it’s 12 minute size and brightness. Framed nicely in my 20 minute field of view.

Typed in the RA and Dec as a user object into my mount’s handset to find it.

Nebula but worked out well using narrowband filters and 2×2 binning.

Data collected on four nights. 13th, 14th, 25th, 28th March 2016.

Sii/ha/oiii image with 5 hours 50 minutes of data. 9 x 10min Sii, 16 x 10min Ha, 10 x 10min Oiii 2×2 binning.