Celestial hemisphere:  Southern  ·  Constellation: Sculptor (Scl)  ·  Contains:  1WGA J0047.9-2509  ·  HD4555  ·  HD4572  ·  MQ J004709.06-251741.6  ·  MQ J004715.86-252332.6  ·  MQ J004717.19-251827.0  ·  MQ J004721.71-251435.3  ·  MQ J004727.94-252643.2  ·  MQ J004734.61-251250.1  ·  MQ J004738.39-251024.7  ·  MQ J004742.88-251513.2  ·  MQ J004801.16-252351.7  ·  MQ J004801.23-252421.8  ·  NGC 253  ·  PGC 198196  ·  PGC 778878  ·  PGC 779458  ·  RX J00473-2510  ·  Sculptor Filament  ·  Sculptor galaxy  ·  Silver Coin
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NGC 253  Sculptor Galaxy - 20 inch Reflector, Paulo Cacella
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NGC 253 Sculptor Galaxy - 20 inch Reflector

Getting plate-solving status, please wait...
NGC 253  Sculptor Galaxy - 20 inch Reflector, Paulo Cacella
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NGC 253 Sculptor Galaxy - 20 inch Reflector

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The Sculptor Galaxy (also known as the Silver CoinSilver Dollar GalaxyNGC 253, or Caldwell 65) is an intermediate spiral galaxy in the constellationSculptor. The Sculptor Galaxy is a starburst galaxy, which means that it is currently undergoing a period of intense star formation.

The Sculptor Galaxy is located at the center of the Sculptor Group, one of the nearest groups of galaxies to the Milky Way.[10] The Sculptor Galaxy (the brightest galaxy in the group and one of the intrinsically brightest galaxies in the vicinity of ours, only surpassed by the Andromeda Galaxy and the Sombrero Galaxy[11]) and the companion galaxies NGC 247PGC 2881PGC 2933Sculptor-dE1, and UGCA 15 form a gravitationally-bound core near the center of the group. Most other galaxies associated with the Sculptor Group are only weakly gravitationally bound to this coreNGC 253's starburst has created several super star clusters on NGC 253's center (discovered with the aid of the Hubble Space Telescope): one with a mass of 1.5*106 solar masses, and absolute magnitude of at least −15, and two others with 5×104 solar masses and absolute magnitudes around −11;[13] later studies have discovered an even more massive cluster heavily obscured by NGC 253's interstellar dust with a mass of 1.4×107 solar masses, an age of around 5.7×106 years, and rich in Wolf-Rayet stars.[14] The super star clusters are arranged in an ellipse around the center of NGC 253, which from the Earth's perspective appears as a flat line.[15]Star formation is also high in the northeast of NGC 253's disk, where a number of red supergiant stars can be found, and in its halo there are young stars as well as some amounts of neutral hydrogen. This, along with other peculiarities found in NGC 253, suggest that a gas-rich dwarf galaxy collided with it 200 million years ago, disturbing its disk and starting the present starburst.[16]As happens in other galaxies suffering strong star formation such as Messier 82NGC 4631, or NGC 4666, the stellar winds of the massive stars produced in the starburst as well as their deaths as supernovae have blown out material to NGC 253's halo in the form of a superwind that seems to be inhibiting star formation in the galaxy.[17]Although supernovae are generally associated with starburst galaxies, only one supernova has been detected within the Sculptor Galaxy.[1] The supernova, named SN 1940E, is located approximately 54″ southwest of the galaxy's nucleus. It was discovered in November 1940.

Research suggests the presence of a supermassive black hole in the center of this galaxy with a mass estimated to be 5 million times that of the Sun, which is slightly heavier than Sagittarius A*
 At least two techniques have been used to measure distances to Sculptor in the past ten years.Using the planetary nebula luminosity function method, an estimate of 10.89 +0.85
−1.24 million light years (or Mly; 3.34 +0.26
−0.38 Megaparsecs, or Mpc) was achieved in 2006.[2]The Sculptor Galaxy is close enough that the tip of the red-giant branch (TRGB) method may also be used to estimate its distance. The estimated distance to Sculptor using this technique in 2004 yielded 12.8 ± 1.2 Mly (3.94 ± 0.37 Mpc).[20][21]A weighted average of the most reliable distance estimates gives a distance of 11.4 ± 0.7 Mly (3.5 ± 0.2 Mpc).

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NGC 253  Sculptor Galaxy - 20 inch Reflector, Paulo Cacella