Celestial hemisphere:  Northern  ·  Constellation: Gemini (Gem)  ·  Contains:  PGC 1420191  ·  PGC 1420816  ·  PGC 1421175  ·  PGC 1421568  ·  PGC 1422135  ·  PGC 1422206  ·  PGC 1432041  ·  PK205+14.1  ·  Sh2-274
Abell21 Medusa Nebula  (Sh2-274) RGB-HO, Jerry Macon
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Abell21 Medusa Nebula (Sh2-274) RGB-HO

Abell21 Medusa Nebula  (Sh2-274) RGB-HO, Jerry Macon
Powered byPixInsight

Abell21 Medusa Nebula (Sh2-274) RGB-HO

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Description

The RGB image is the basis of this image. Ha is then added to the R channel, and OIII added to the B channel. It is interesting to contrast this with my earlier HOO image using the same Ha and OIII used in this image.

The Medusa Nebula is a large planetary nebula in the constellation of Gemini on the Canis Minor border. It also known as Abell 21 and Sharpless 2-274. It was originally discovered in 1955 by UCLA astronomer George O. Abell, who classified it as an old planetary nebula.[4] The braided serpentine filaments of glowing gas suggests the serpent hair of Medusa found in ancient Greek mythology.

Until the early 1970s, the Medusa was thought to be a supernova remnant. With the computation of expansion velocities and the thermal character of the radio emission, Soviet astronomers in 1971 concluded that it was most likely a planetary nebula.

As the nebula is so big, its surface brightness is very low, with surface magnitudes of between +15.99 and +25 reported. Because of this most websites recommend at least an 8-inch (200 mm) telescope with an [O III] filter to find this object although probably possible to image with smaller apertures.

(Wikipedia)

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Abell21 Medusa Nebula  (Sh2-274) RGB-HO, Jerry Macon

In these public groups

Abell Planetary Nebula

In these collections

Sharpless 2 Objects