Medusa Nebula
| Nebula | |
|---|---|
 Medusa nebula, 24 inch telescope on Mt. Lemmon, AZ. | |
| Observation data: J2000.0 epoch | |
| Right ascension | 07h 29m 02.69s[1][2] |
| Declination | +13° 14′ 48.4″[1][2] |
| Distance | 1,500 ly (460 pc)[3] ly |
| Apparent magnitude (V) | 15.99[1] |
| Apparent dimensions (V) | 4 ly[3] |
| Constellation | Gemini |
| Physical characteristics | |
| Absolute magnitude (V) | 7.68 |
| Notable features | Very large & very low surface brightness |
| Designations | Sharpless 2-274, PK 205+14 1, Abel 21 [1] |
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.[4]
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.[citation needed]
See also
References
- ^ a b c d "MEDUSA -- Planetary Nebula". Centre de Données astronomiques de Strasbourg. Retrieved 1 July 2010.
- ^ a b Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; Beichman, C. A.; et al. (June 2003). "2MASS All Sky Catalog of point sources". The IRSA 2MASS All-Sky Point Source Catalog, NASA/IPAC Infrared Science Archive. Bibcode:2003tmc..book.....C.
- ^ a b Nemiroff, R.; Bonnell, J., eds. (12 June 2010). "The Medusa Nebula". Astronomy Picture of the Day. NASA. Retrieved 1 July 2010.
- ^ a b Lozinskaya, T. A. (June 1973). "Interferometry of the Medusa Nebula A21 (YM 29)". Soviet Astronomy. 16: 945. Bibcode:1973SvA....16..945L.
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External links
- The Sharpless Catalog: Sharpless 274
- APOD picture: The Medusa Nebula
- Images of the Universe: PK 205+14.1 The Medusa Nebula in Gemini