. 24/7 Space News .
Hubble - Graceful Dance Of Interacting Galaxies

Arp 87 is a stunning pair of interacting galaxies. Stars, gas, and dust flow from the large spiral galaxy, NGC 3808, forming an enveloping arm around its companion. The shapes of both galaxies have been distorted by their gravitational interaction. Arp 87 is located in the constellation of Leo, the Lion, approximately 300 million light-years away from Earth. Arp 87 appears in Arp's Atlas of Peculiar Galaxies. As also seen in similar interacting galaxies, the corkscrew shape of the tidal material suggests that some stars and gas drawn from the larger galaxy have been caught in the gravitational pull of the smaller one. This image was taken in February 2007 with Hubble's Wide Field Planetary Camera 2 detector. Credits: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)
by Staff Writers
Paris, France (ESA) Oct 31, 2007
Two galaxies, containing a vast number of stars, swing past each other in a graceful dance choreographed by gravity, as seen by Hubble. The pair of galaxies collectively known as Arp 87 is among the hundreds of interacting and merging galaxies known in our nearby Universe. The Arp 87 pair was originally discovered and catalogued by astronomer Halton Arp in the 1970s. The 'Arp's Atlas of Peculiar Galaxies' is a compilation of astronomical photographs using the Palomar 200-inch Hale and the 48-inch Samuel Oschin telescopes.

The two main players comprising Arp 87 are NGC 3808 (the larger of the two galaxies, on the right, in the image below) and its companion NGC 3808A (on the left, in the image below). NGC 3808 is a nearly face-on spiral galaxy with a bright ring of star formation and several prominent dust arms. Stars, gas, and dust flow from NGC 3808, forming an enveloping arm around its companion. NGC 3808A is a spiral galaxy seen edge-on and is surrounded by a rotating ring that contains stars and interstellar gas clouds. The ring is situated perpendicular to the plane of the host galaxy disk and is called a 'polar ring.'

As seen in other mergers similar to Arp 87, the corkscrew shape of the tidal material (or bridge of shared matter) between the two galaxies suggests that some stars and gas drawn from the larger galaxy have been caught in the gravitational pull of the smaller one.

The shapes of both galaxies have been distorted by their gravitational interaction with one another.

Interacting galaxies often exhibit high rates of star formation. Many lines of evidence - colours of their starlight, intensity of emission lines from interstellar gas, far-infrared output from heated interstellar dust - support this fact. Some merging galaxies have the highest levels of star formation we can find anywhere in the nearby Universe

A major aspect of this excess star formation was properly revealed only when Hubble turned its imaging capabilities toward colliding galaxies. Among the observatory's first discoveries was that galaxies with very active star formation contain large numbers of super star clusters - clusters more compact and richer in young stars than astronomers were accustomed to seeing in our galactic neighborhood.

Arp 87 is in the constellation Leo, the Lion, approximately 300 million light-years away from Earth. These observations were taken in February 2007 with the Wide Field Planetary Camera 2. Light from isolated blue, green, red, and infrared ranges was combined to form this colour image.

Community
Email This Article
Comment On This Article

Related Links
Hubble European Information Centre
Hubblecast
Stellar Chemistry, The Universe And All Within It



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


Bonn Astronomers Simulate Life And Death In The Universe
Bonn, Germany (SPX) Oct 30, 2007
Stars always evolve in the universe in large groups, known as clusters. Astronomers distinguish these formations by their age and size. The question of how star clusters are created from interstellar gas clouds and why they then develop in different ways has now been answered by researchers at the Argelander Institute for Astronomy at the University of Bonn with the aid of computer simulations. The scientists have solved - at least at a theoretical level - one of the oldest astronomical puzzles, namely the question of whether star clusters differ in their internal structure.







  • China to deploy theft patrol on Everest
  • I Want To Be A Space Millionaire
  • Canine pioneer: Soviet mutt was first earthling in space
  • Seven Chinese apply to be space tourists

  • Spirit Continues Studies Of Rocks On Home Plate
  • Phoenix: Tasks En Route To Mars Include Course Tweak And Gear Checks
  • Mars Ice Shaken Not Stirred
  • UA's Phoenix Mars Mission Gets A Chance To Lounge

  • South Korean Rocket To Make First Launch In 2008
  • Russia To Launch German Satellite On November 1st
  • Arianespace Prepares The Fifth And Sixth Ariane 5 For 2007 Launches
  • Russia launches first Proton rocket after crash

  • DMCii Satellite Imaging Helps Dramatically Reduce Deforestation Of Amazon Basin
  • NASA Views Southern California Fires And Winds
  • A Roadmap For Calibration And Validation
  • GeoEye Contract With ITT Begins Phased Procurement Of The GeoEye-2 Satellite

  • Goddard Instrument Makes Cover Of Science
  • Checking Out New Horizons
  • Pluto-Bound New Horizons Sees Changes In Jupiter System
  • Maneuver Puts New Horizons On A Straight Path To Pluto

  • Hubble - Graceful Dance Of Interacting Galaxies
  • Bonn Astronomers Simulate Life And Death In The Universe
  • Dwarf Galaxies Need Dark Matter Too
  • To Catch A Galactic Thief

  • NASA To Establish Nationwide Lunar Science Institute
  • If We Had No Moon
  • China Eyes The Moon
  • China's Lunar Orbiter, The Story Behind "Moon Lady" Chang'e

  • Russia Launches Proton Carrier Rocket After The Ban
  • EU's Galileo satnav scheme needs millions more next year: MEPs
  • Another GPS Satellite Successfully Launched
  • Science And Galileo - Working Together

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement