The Sculptor Galaxy (NGC 253)

Sculptor Galaxy
Description:

 

"I see no stars in it." So said astronomer John Hershel while observing this object with an 18" telescope in the 1830s from South Africa. It was not until the 1920s that the true nature of galaxies was revealed, when Edwin Hubble was able to resolve individual stars in the Andromeda Galaxy in photographs taken with the new 100" Hooker telescope (at the time, the largest in the world). Now we know that galaxies are islands of tens or hundreds of billions of stars.

The Sculptor Galaxy is actually part of a small group of galaxies in the constellation Sculptor that is referred to as the "Sculptor Galaxy Cluster" or the ”South Polar Galaxy Cluster" (since the cluster extends all the way to the south celestial pole).

The Sculptor Galaxy, sometimes called the "Silver Coin Galaxy," is a large spiral galaxy inclined 12 degrees to us. It has an estimated mass of 100 billion solar masses, and a distance of 12 million light years based on a recent study of planetary nebulae in the galaxy and a measured recessional redshift of 0.00081.

The Sculptor Galaxy is a "starburst" galaxy, meaning that there are several areas where star formation is occurring at a prodigious rate. This phenomenon is associated with the large amount of interstellar dust in this galaxy, which is visible as dark lanes and blotches.

The Sculptor constellation is low in the southern sky during the winter for observers in the northern hemisphere, making it a challenging object to image. With a diameter of 29 arcminutes, the galaxy spans an area of the sky equal to a full Moon. But at magnitude 7.3, it is only visible with binoculars or a telescope, and its true dimensions are not perceptible without a camera.

 

Image Name:

The Sculptor Galaxy

Date Taken:

August 22, 2014

Location Taken:

Siding Spring Observatory, NSW Australia

Conditions of Location:

Equipment Used:

Planewave 17" corrected Dall-Kirkham telescope, FLI PL4710 camera

Processing Used:

18 x 5 minutes luminance, and 8 x 3 minutes RGB, guided, processed in Maxim DL and Photoshop. Total exposure 2 hours 45 minutes. The target was at 88 degrees altitude.

Distance from Location:

12 million light years

Constellation:

Sculptor

Other Link:

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