NGC 4656/57

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Galaxy
NGC 4656/57
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GALEX image of NGC 4656/57; the entry NGC 4657 is based on the slightly offset structure in the upper left corner of the image.
GALEX image of NGC 4656/57; the entry NGC 4657 is based on the slightly offset structure in the upper left corner of the image.
AladinLite
Constellation Hunting dogs
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 12 h 43 m 57.7 s
declination + 32 ° 10 ′ 05 ″
Appearance
Morphological type SB (s) m / pec / HII  
Brightness  (visual) 10.1 mag
Brightness  (B-band) 10.7 mag
Angular expansion 15.3 ′ × 2.4 ′
Position angle 33 °
Surface brightness 13.9 mag / arcmin²
Physical data
Affiliation NGC-4631 group
(LGG 291)  
Redshift 0.002155 ± 0.000003  
Radial velocity 646 ± 1 km / s  
Stroke distance
v rad  / H 0 		(30 ± 2)  x  10 6  ly
(9.12 ± 0.64)  Mpc 
history
discovery Wilhelm Herschel
Discovery date March 20, 1787
Catalog names
NGC  4656 • NGC 4657 • UGC  7907 • PGC  42863 • CGCG  159-065 • MCG  + 05-30-66 • IRAS  12417 + 3228 • KUG  1241 + 324 • 2MASX  J1243582 + 321010 • GC  3189 • GC 3190 • H  I-176 • H I-177 • h  1414 • h 1415 • KCPG 350B • FGC 174A

NGC 4656/57 is a barred spiral galaxy of Hubble type SB (s) m in the constellation Canes Venatici the northern sky , the estimated 30 million light-years from the Milky Way 's center.

The appearance of the galaxy is reminiscent of the Small Magellanic Cloud . Because of its characteristic shape, the galaxy is sometimes jokingly called a hockey stick . In the past, the galaxy evidently had a strong interaction with the large neighboring galaxy NGC 4631, a little further to the southeast . One of the effects of this is likely to be a bright, somewhat remote appearing node at the northeastern end of the galaxy. This bright knot was cataloged as a separate object when Wilhelm Herschel discovered the galaxy on March 20, 1787 , which meant that it was later listed in the New General Catalog under a separate entry as NGC 4657 .

Web links

Commons : NGC 4656/57  - collection of images, videos, and audio files

Individual evidence

  1. ↑ a b c d e NASA / IPAC EXTRAGALACTIC DATABASE. NGC 4656
  2. ↑ a b c SEDS : NGC 4656
  3. ↑ General study of group membership; Astronomy and Astrophysics Supplement Series
  4. ↑ Seligman