The Medusa Nebula: Abell 21 in Gemini | Mayall Telescope
The Medusa Nebula, known scientifically as Abell 21 and as Sharpless 2-274, is an old planetary nebula about 1,500 light-years away in the constellation Gemini. It is estimated to be over 4 light-years across.
The Medusa Nebula was originally discovered in 1955 by University of California, Los Angeles astronomer George O. Abell. The central star of this planetary nebula is a PG 1159 star. A PG 1159 star, often also called a pre-degenerate, is a star with a hydrogen-deficient atmosphere that is in transition between being the central star of a planetary nebula and being a hot white dwarf. These stars are hot, with surface temperatures between 75,000 K and 200,000 K. They are characterized by atmospheres with little hydrogen and absorption lines for helium, carbon and oxygen.
This image was taken by the Mayall Telescope's mosaic camera with [OIII] (assigned a blue color) and H-alpha (orange) filters.
Learn more about the Mayall Telescope:
https://noirlab.edu/science/programs/kpno/telescopes/nicholas-mayall-4m-telescope
Release Date: April 21, 2009
#NASA #Astronomy #Space #Science #Stars #Nebulae #PlanetaryNebulae #MedusaNebula #Sh2274 #Abell21 #GeminiConstellation #Cosmos #Universe #MayallTelescope #KPNO #Arizona #NSF #AURA #UnitedStates #STEM #Education
No comments:
Post a Comment