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Астронет: Астрономическая картинка дня Arp 87: сливающиеся галактики от телескопа им.Хаббла http://variable-stars.ru/db/msg/1350330/eng  | 
Credit & Copyright: Douglas Gardner    
 
Explanation:
This dance is to the death.    
   
Along the way, as these two large galaxies duel, a    
cosmic bridge of stars, gas, and dust currently stretches   
over 75,000 light-years and joins them.    
   
The bridge itself is strong evidence   
that these two immense star systems have   
passed close to each other   
and experienced violent tides induced by   
mutual   
gravity.   
   
As further evidence, the face-on spiral galaxy on   
the right, also known as NGC 3808A,   
exhibits many young blue star clusters produced in a burst   
of star formation.   
   
The twisted edge-on spiral on the left (NGC 3808B) seems to be wrapped   
in the material bridging the galaxies and   
surrounded by a curious   
polar ring.   
   
Together, the system is known as    
Arp 87    
and morphologically classified, technically, as    
peculiar.   
   
While such interactions are drawn out over billions of years, repeated   
close passages    
should ultimately result in the death of one galaxy in the sense that    
only one galaxy will eventually result.   
   
Although   
this scenario    
does look peculiar, galactic mergers are thought   
to be common, with Arp 87 representing a stage in   
this   
inevitable process.   
   
The Arp 87 pair are   
about 300 million light-years   
distant toward the constellation Leo.   
   
The prominent edge-on spiral at the far left   
appears to be a more distant background galaxy and   
not involved in the on-going merger.   
   
 Authors & editors: 
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official:  Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.

