Messier 82

from Wikipedia, the free encyclopedia
Galaxy
Messier 82
{{{Card text}}}
M82 HST ACS 2006-14-a-large web.jpg
Photo from the Hubble Space Telescope
AladinLite
Constellation Big Bear
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 09 h 55 m 52.7 s
declination + 69 ° 40 ′ 46 ″
Appearance
Morphological type I0; Sbrst HII  
Brightness  (visual) 8.6 likes
Brightness  (B-band) 9.2 likes
Angular expansion 11.2 '× 4.3'
Position angle 65 °
Surface brightness 12.7 mag / arcmin²
Physical data
Affiliation M81 group
Virgo superclusters , LGG 176  
Redshift +0.000677 ± 0.000013  
Radial velocity (+203 ± 4) km / s  
Stroke distance
v rad  / H 0 		(14 ± 1)  x  10 6  ly
(4.28 ± 0.31)  Mpc 
diameter 40,000 ly
history
discovery Johann Elert Bode
Discovery date December 31, 1774
Catalog names
M  82 • NGC  3034 • UGC  5322 • PGC  28655 • CGCG  333-008 • MCG  + 12-10-11 • IRAS  09517 + 6954 • Arp  337 • GC  1950 • H  IV 79 • 3C 231 • KCPG 218B • Bode 18 • Koehler 8B

Messier 82 (also known as NGC 3034 , M82 or "Cigar Galaxy") is a spiral galaxy with dimensions 11.2 '× 4.3' and an apparent magnitude of 8.6 mag in the constellation Great Bear .

M82 is gravitationally bound to the somewhat larger spiral galaxy M81 and forms with it the core of the M81 galaxy group.

description

Photograph with the inscription of some striking celestial objects in the vicinity of the galaxies M 81 and M 82. Left and below the constellation Great Bear with the stars Merak and Dubhe can be seen. At the top right is the dragon constellation with the star Giausar in the tip of the dragon's tail.

For a long time M82 was assigned to the irregular galaxy type . However, recent studies in the near infrared show spiral arms. The galaxy thus probably corresponds to the morphological type of a bar-spiral galaxy (Sbc), that is, the arms arise at the ends of a bar that is not particularly long in this case.

Nearby is the bright spiral galaxy M81 , with which it forms a physically bound pair and forms the core of the M81 group of galaxies , some 12 million light years away . The M82 galaxy was dramatically changed by interacting with M81 on a close flyby about 500 million years ago. In the inner area, the rate at which new stars form from interstellar matter has increased significantly ( starburst ). This makes M82 one of the brightest infrared galaxies and one of the brightest galaxies in the radio range (Ursa Major A) . As a result of the starburst, supernova explosions create a turbulent gas movement, which is observed as an outflow perpendicular to the galaxy plane of M82. Due to its proximity and brightness, M82 is one of the best-studied starburst galaxies.

M82 contains the ultra- bright X- ray source M82 X-1 in one of its star clusters . The medium-weight black hole with around 415 solar masses is orbited by an extremely heavy star. In 2014, another ultra-luminous X-ray source was discovered with the M82 X-2 , the radiation here emanating from an X-ray pulsar .

Halton Arp organized his catalog of unusual galaxies into groups according to purely morphological criteria. This galaxy belongs to the class Various (Arp catalog) .

The galaxy was discovered on December 31, 1774 by the German astronomer Johann Elert Bode .

Supernova 2014J

On January 21, 2014, university professor Steve Fossey and four students from University College London accidentally discovered a type Ia supernova , which is the explosion of a white dwarf according to current theory, while training at the telescope outside the galaxy . It can already be seen on recordings from January 15, 2014 and was given the identifier SN 2014J .

Above: View of M82 on December 10, 2013.
Below: View on January 21, 2014 with SN 2014J.

Other pictures

literature

  • Wolfgang Steinicke: A nightmare for the Herschel family. Stars and Space 46 (2), pp. 61-65 (2007), ISSN  0039-1263 ; Discovery of the galaxies M81 and M82
  • Jeff Kanipe and Dennis Webb: The Arp Atlas of Peculiar Galaxies - A Chronicle and Observer's Guide , Richmond 2006, ISBN 978-0-943396-76-7

Web links

Commons : Messier 82  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d e f NASA / IPAC EXTRAGALACTIC DATABASE
  2. ↑ a b c d e SEDS : NGC 3034
  3. ^ Messier Object 82. In: messier.seds.org. Retrieved December 7, 2015 .
  4. ↑ Seligman
  5. ↑ Peter Gotzner: Astronomical lucky strike: Students discover supernova by chance , Spiegel Online, January 23, 2014
  6. ↑ astronews.com March 4, 2014