The Ring Nebula (NGC 6720)
About this image
This is a two-minute exposure taken
on the night of September 26th 1994 (UT of observation 27/09/94:04:21).
This photograph shows a region 150 arc seconds square. The first
image has been compressed in brightness (approximately a double
logarithm) to show both bright and faint features.
The second image is a pseudo-color version of the same original,
which is used to show more of the fainter features while not saturating
the bright regions.
Although sky conditions were not the best that Kitt Peak can offer,
this image has a "seeing" measurement (average
FWHM of several stars) of about 0.8 arc seconds.
The image has not been re-oriented to remove either the CCD orientation
or the field rotation of the altitude-azimuth design of the WIYN telescope,
and is therefore shown with E up and S to the left.
About this object
The Ring Nebula, also known as M57 or NGC 6720, is found in the constellation
Lyra. A spherical shell of glowing gas surrounds a central hot star.
The nebula was formed by the nova of the central star - a sudden release of a
large portion of the star's mass. The Ring Nebula was the first planetary
nebula discovered, so called because of its visual spherical appearance
through telescopes in the past. It has a diameter a little under two light
years and is 5000 light years from Earth (angular size 1.2 arc minutes).
Location: 18 53.6 +33 02 (2000)