NGC 253 (Caldwell 65)
NGC 253 is a spiral galaxy in the constellation Sculptor. It has an apparent visual magnitude of 8.0 and an angular diameter is 6.8 × 27.5 arc-minutes. The Equinox 2000 coordinates are RA= 0h 47.5m, Dec= -25° 17´.
The image above shows the full frame view of NGC 253 through the Astro-Physics 130EDF APO Refractor (130mm, f/6, fl=780mm).
As one of the brightest galaxies in the sky, the Sculptor Galaxy can be seen through binoculars and is near the star Beta Ceti. It is considered one of the most easily viewed galaxies in the sky after the Andromeda Galaxy (M31). Because of its prominence and the fact that Messier did not include it in his own Messier Catalog, Sir Patrick Moore added it to his Caldwell Catalog as Caldwell 65.
The galaxy was discovered by Caroline Herschel in 1783 during one of her systematic comet searches. About half a century later, John Herschel observed it using his 18-inch metallic mirror reflector at the Cape of Good Hope. He wrote: "very bright and large (24' in length); a superb object... Its light is somewhat streaky, but I see no stars in it except 4 large and one very small one, and these seem not to belong to it, there being many near..." (description from Wikipedia)
NGC 253 is a starburst galaxy, meaning it is presently undergoing a period of intense star formation. The presence of young stars in its halo as well as neutral hydrogen suggests that a gas-rich dwarf galaxy collided with NGC 253 about 200 million years ago, disturbing its disk and starting the present starburst. Furthermore, some research indicates the core of the galaxy contains a supermassive black hole with a mass estimated to be 5 million times greater than the Sun.
For more information, see the entry for NGC 253 in Wikipedia and NGC 253 in SEDS.
Technical Details
- Objects: NGC 253
- Other Names:Sculptor Galaxy, Silver Dollar Galaxy
- Object Type: spiral galaxy
- Object Data: Apparent Magnitude = 8.0, Angular Size = 6.8 × 27.5 arc-minutes
- Object Position (Equinox 2000): RA= 0h 47.5m, Dec= -25° 17´
- Date: 2019 Sep 28
- Location: Bifrost Astronomical Observatory, Portal, AZ
- Telescope: Astro-Physics 130EDF APO Refractor (130mm, f/6, fl=780mm)
- Mount: Astro-Physics 1200GTO
- Camera: ZWO ASI183MC Pro
- Field of View: 58.2' x 38.8' at 0.63 arc-sec/pixel
- Exposure: 22 x 300 sec (= 1 hr 50 min), f/6, Unit Gain, Temp.=-15° C
- File Name: NGC253-2019Sep28-1a.jpg
- Processing (Deep Sky Stacker): using Lights, Darks and Flats
- Processing (Photoshop CC): Curves, Levels, Layer Masks, Vibrance, Noise Reduction
- Original Image Size: 5496 × 3672 pixels (20.2 MP); 18.3" x 12.3" @ 300 dpi
- Rights: Copyright 2019 by Fred Espenak. All Rights Reserved. See: Image Licensing.