M57 is the most observed planetary nebula in the night sky. One reason is that it is very easy to find. The Ring Nebula sits between two bright stars in Lyra, 3.5 magnitude Sheliak and 3.3 magnitude Sulaphat. These two stars and two to the north form a parallelogram pattern in Lyra. Of course, Vega is the brightest star in Lyra and also the brightest star in the summer sky. The challenge of M57 is its small size. It is easy to mistake for a star at low magnification. Once you locate Sulaphat and Sheliak, drop in a high power eyepiece and slowly scan about halfway between those stars.
Summer Sky Tour: M57-The Ring Nebula (Lyra) RA: 18h 53.6m / DEC: +33° 01'.8 |
The drawing at left is based on a 388X view (8.8 mm UWA with a TeleVue 3X Barlow) over a 13' diameter true field. This magnitude 8.8 planetary nebula displays an oval shape elongated across an 3'x2' area. A 40" thick bright outer ring surrounds a circular inner region some 70" across. Subtle, faint lobes at the east and west limit of the annulus give the nebula an elongated appearance. The 15.2 magnitude central star of the Ring Nebula is a difficult detection unless conditions feature both good transparency and steady seeing. I was able to detect the central star on this night and suspect an 8-inch aperture could do the trick. I used several faint field stars of known magnitude to confirm my sighting of the central star. Magnitude 13.03 GSC 2642-0433, is visible near the eastern edge of the nebula. Magnitude 14.17 GSC 2642-0239 is roughly 90" southeast of M57. Magnitude 14.61 J185331+3302.5 is shown to the northwest. A 15th magnitude star is located 10" to the west of J185331+3302.5. There is a 12th magnitude star embedded in the western section of the lobe. A star estimated by Todd Gross to be magnitude 15.6 is visible 60" north of this lobe star. |
Home | About Cosmic Voyage | Getting Started | Deep-sky Observing | Planetary Observing | Astrophotography | Sketching | Glossary | Web Links
URL: http://www.cosmicvoyage.net
Layout, design & revisions © W. D. Ferris
Comments and Suggestions: wdferris1@gmail.com
Revised: February 14, 2002 [WDF]