December 4, 2010

Some images from the last two months:

M42 - The Great Orion Nebula

The brightest nebula in the northern sky, easily visible to the naked eye as the "fuzzy star" in Orion's Sword, this vast emission nebula is actually a massive stellar nursery, and merely a blister on a larger cloud of gas that extends for thousands of light years across the constellation of Orion. The nebula's wispy structure results from hydrogen gas being scuplted by stellar winds coming from stars within the nebula itself. M42 spans 24 light years in diameter and is located about 1,300 light years away.

The above image comprises 35, 180-second subexposures taken on December 3, 2010, for a total exposure time of 105 minutes.

M1 - The Crab Nebula

This fame nebula in the constellation Taurus is all that remains of a star that went supernova. The light from the blast was observed by Chinese astronomers in 1054 AD. The nebula is located about 6,500 light years from Earth.

The above image is a crop of the larger image below.

This image was comprised of 50, 300-second subexposures taken in September, October and November for a total exposure time of over four hours.

M33 - The Triangulum Galaxy

Appearing in the constellation Triangulum, M33 is a large spiral galaxy seen face on. Part of the local group of galaxies, it is thought to be much smaller than either the Andromeda Galaxy or the Milky Way Galaxy, both of which have hundreds of billions of stars. M33 is thought to have less than 100 billion resident stars. Though large, the galaxy has a low surface brightness and is consequently difficult to see with telescopes.

This image was composed of 59, 300-second subexposures taken in August, September, October and November. Total exposure time was almost five hours.

NGC884 & NGC869 - The Double Cluster

These two bright open clusters have been known to skywatchers since antiquity, noted by ancient Greek astronomers. They can be seen with the naked eye on clear, dark nights in the constellation of Perseus, appearing as a fuzzy double star. A pair of binoculars or a small telescope will resolve the clusters into hundreds of stars. The clusters are believed to lie relatively close together about 7,000 light years away.

This image comprises 13, 300-second subexposures taken on October 2, for a total exposure time of over one hour.