UGC 12158 or PGC 69533 is an Sb-type

barred spiral galaxy A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies in the local universe, and generally affect both the motions of stars and interstellar gas ...

located approximately away from Earth in the constellation of

Pegasus Pegasus (; ) is a winged horse in Greek mythology, usually depicted as a white stallion. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. Pegasus was the brother of Chrysaor, both born from Medusa's blood w ...

. Its tight spiral disk spans approximately , whose scale at heliocentric distance is about 36.9

kiloparsec The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, a ...

s per

arcminute A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...

. It is also often stated to resemble the

Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

in appearance, with a similar central bar and spiral arm structure. The earliest known reference to this galaxy comes from part 2 of the

Morphological Catalogue of Galaxies The Morphological Catalogue of Galaxies (MCG) or Morfologiceskij Katalog Galaktik, is a Russian catalogue of 30,642 galaxies compiled by Boris Vorontsov-Velyaminov and V. P. Arkhipova. It is based on scrutiny of prints of the Palomar Sky Surv ...

, published in 1964, where it is listed as MCG +03-57-032.

Supernova

On 4 September 2004, Tom Boles discovered a 18.5v magnitude

Type Ia supernova A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...

on one of the spiral arms near the apparent centre in UGC 12158. It was independently discovered by Mark Armstrong the following day, and subsequently designated SN 2004ef. (Blue star within UGC 12158 in Starbox Hubble's Space Telescope image.) Optical spectra was obtained on 7 September 2004 confirming the Type I classification. It reached 17.0v magnitude on 9 September 2004 before fading from view. No progenitor star was found on earlier survey images.

Image gallery

File:Asteroid photobombs Hubble snapshot of Galaxy UGC 12158 (heic2407a).jpg, UGC 12158 imaged by the

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

. The lines are a foreground asteroid moving through the field of view.

References

External links

*
Barred spiral bares all

The Milky Way's (almost) identical twin
12158 +03-57-032 Pegasus (constellation) Barred spiral galaxies 069533 {{Spiral-galaxy-stub

Supernova

Image gallery

See also

References

External links