NGC 4449

from Wikipedia, the free encyclopedia
Galaxy
NGC 4449
{{{Card text}}}
Starburst in NGC 4449 (captured by the Hubble Space Telescope) .jpg
Photo from the Hubble Space Telescope
AladinLite
Constellation Hunting dogs
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 12 h 28 m 11.1 s
declination + 44 ° 05 ′ 37 ″
Appearance
Morphological type IBm; HII Sbrst  
Brightness  (visual) 9.4 mag
Brightness  (B-band) 10.0 mag
Angular expansion 6.2 ′ × 4.4 ′
Position angle 45 °
Surface brightness 12.8 mag / arcmin²
Physical data
Affiliation LGG 290  
Redshift (+680 ± 10)  ·  10 −6  
Radial velocity +204 ± 3 km / s  
Stroke distance
v rad  / H 0 		(12 ± 1)  x  10 6  ly
(3.55 ± 0.26)  Mpc 
history
discovery Wilhelm Herschel
Discovery date April 27, 1788
Catalog names
NGC  4449 • UGC  7592 • PGC  40973 • CGCG  216-005 • MCG  + 07-26-09 • 2MASX  J12281111 + 4405368 • GC  3002 • H  I 213 • h  1281 • LDCE 0867 NED113

NGC 4449 is an irregular galaxy of the Large Magellanic Cloud type, also known as the LMC type, in the constellation Hounds . The object is about 12 million light years away and, with a total mass of 30 billion solar masses, is one of the most massive galaxies of its type. The diameter of the galaxy is about 20,000 light years. The radio spectrum shows that the " dwarf galaxy " is embedded in a gaseous halo almost 200,000 light years in diameter, a remarkable thousand times the volume of the visible galaxy.

Originally a barred spiral galaxy , it changed its shape due to enormous gravitational forces upon penetration, i.e. quasi collision with the neighboring dwarf galaxy UGC 7577 , which took place around 500 million years ago. This created hot gas areas from which so-called starbursts emerged , regions with star-forming zones. These impress in RGB images as blue and red condensations.

The object was discovered on April 27, 1788 by the German-British astronomer William Herschel .

Web links

Individual evidence

  1. ↑ a b c d e NASA / IPAC EXTRAGALACTIC DATABASE
  2. ↑ a b c d e f SEDS : NGC 4449
  3. ↑ Stars and Space April 2013 p. 76
  4. ↑ Seligman