April 24, 2010

The summer sky now rises well before dawn, offering an opportunity to capture a preview of its gems well before the season actually arrives...

M20

Know as the Trifid Nebula due to the dark dust lane that seems to divide the bright red cloud into three parts, this object has long been a favorite of both amateur and professional astronomers. For the amateur, it is relatively bright and thus easily located even with small scopes and even binoculars. Professional astronomers have been thrilled by the discovery that the Trifid combines reflection and emission nebulae, a star cluster, and contains a stellar nursery deep in its colorful clouds in which new stars are forming.

Added to Messier's catalog in 1764, the Trifid appears in a dense starfield in Sagittarius - the Lagoon Nebula (M8) lies just to the south. Astronomers place the nebula about 5,200 light years from Earth.

The above image comprises 11, 300-second subexposures, taken on April 19, and 11, 200-second subexposures, taken on April 24, for a total exposure time of 92 minutes.

M16

This is an open star cluster that lies amid an emission nebula, whose striking shape has led astronomers to dub it the Eagle Nebula. The intriguing structures of dust and gas at the nebula's center were imaged by the Hubble Telescope almost a decade ago, producing one of the Hubble's most famous images, "The Pillars of Creation," which showed enormous clouds of gas enveloping new born stars. The entire nebula is a stellar nursery. Astronomers estimate the nebula's age at 5.5 million years, and place it about 7,000 light years from Earth.

M16 is readily visible through binoculars or a small telescope.

This image is comprised of seven 300-second subexposures, for a total exposure of 35 minutes.