Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



Interstellar Chemistry Gets More Complex With New Charged-Molecule Discovery

Astronomers using the Robert C. Byrd Green Bank Telescope found the negatively-charged form of octatetraynyl (C8H-) in a cold interstellar cloud (middle left) and in the gaseous envelope surrounding an old, evolved star (middle right). This is the largest negatively-charged molecule yet found in space. The scientists believe it probably is formed in steps, illustrated here, proceeding downward. 1. A molecule of C2H attaches to a molecule of C6H2, producing a molecule of C8H2 and a hydrogen atom. 2. Radiation (squiggly line) breaks one hydrogen atom from the C8H2, leaving C8H and a hydrogen atom. 3. Finally, an electron attaches itself to the C8H molecule, freeing a burst of radiation (overall glow seen around the molecule) and leaving the negatively-charged ion C8H-. CREDIT: Bill Saxton, NRAO/AUI/NSF
by Staff Writers
Green Bank WV (SPX) Jul 25, 2007
Astronomers using data from the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) have found the largest negatively-charged molecule yet seen in space. The discovery of the third negatively-charged molecule, called an anion, in less than a year and the size of the latest anion will force a drastic revision of theoretical models of interstellar chemistry, the astronomers say.

"This discovery continues to add to the diversity and complexity that is already seen in the chemistry of interstellar space," said Anthony J. Remijan of the National Radio Astronomy Observatory (NRAO). "It also adds to the number of paths available for making the complex organic molecules and other large molecular species that may be precursors to life in the giant clouds from which stars and planets are formed," he added.

Two teams of scientists found negatively-charged octatetraynyl, a chain of eight carbon atoms and one hydrogen atom, in the envelope of gas around an old, evolved star and in a cold, dark cloud of molecular gas. In both cases, the molecule had an extra electron, giving it a negative charge. About 130 neutral and about a dozen positively-charged molecules have been discovered in space, but the first negatively-charged molecule was not discovered until late last year. The largest previously-discovered negative ion found in space has six carbon atoms and one hydrogen atom.

"Until recently, many theoretical models of how chemical reactions evolve in interstellar space have largely neglected the presence of anions. This can no longer be the case, and this means that there are many more ways to build large organic molecules in cosmic environments than have been explored," said Jan M. Hollis of NASA's Goddard Space Flight Center (GSFC).

Ultraviolet light from stars can knock an electron off a molecule, creating a positively-charged ion. Astronomers had thought that molecules would not be able to retain an extra electron, and thus a negative charge, in interstellar space for a significant time. "That obviously is not the case," said Mike McCarthy of the Harvard-Smithsonian Center for Astrophysics. "Anions are surprisingly abundant in these regions."

Remijan and his colleagues found the octatetraynyl anions in the envelope of the evolved giant star IRC +10 216, about 550 light-years from Earth in the constellation Leo. They found radio waves emitted at specific frequencies characteristic of the charged molecule by searching archival data from the GBT, the largest fully-steerable radio telescope in the world.

Another team from the Harvard-Smithsonian Center for Astrophysics (CfA) found the same characteristic emission when they observed a cold cloud of molecular gas called TMC-1 in the constellation Taurus. These observations also were done with the GBT. In both cases, preceding laboratory experiments by the CfA team showed which radio frequencies actually are emitted by the molecule, and thus told the astronomers what to look for.

"It is essential that likely interstellar molecule candidates are first studied in laboratory experiments so that the radio frequencies they can emit are known in advance of an astronomical observation," said Frank Lovas of the National Institute of Standards and Technology (NIST).

Both teams announced their results in the July 20 edition of the Astrophysical Journal Letters.

"With three negatively-charged molecules now found in a short period of time, and in very different environments, it appears that many more probably exist. We believe that we can discover more new species using very sensitive and advanced radio telescopes such as the GBT, once they have been characterized in the laboratory," said Sandra Bruenken of the CfA.

"Further detailed studies of anions, including astronomical observations, laboratory studies, and theoretical calculations, will allow us to use them to reveal new information about the physical and chemical processes going on in interstellar space," said Martin Cordiner, of Queen's University in Belfast, Northern Ireland.

"The GBT continues to take a leading role in discovering, identifying and mapping the distribution of the largest molecules ever found in astronomical environments and will continue to do so for the next several decades," said Phil Jewell of NRAO.

In addition to Hollis, Lovas, Cordiner and Jewell, Remijan worked with Tom Millar of Queen's University in Belfast, Northern Ireland, and Andrew Markwick-Kemper of the University of Manchester in the UK.

Bruenken worked with McCarthy, Harshal Gupta, Carl Gottlieb, and Patrick Thaddeus, all of the Harvard-Smithsonian Center for Astrophysics.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Community
Email This Article
Comment On This Article

Related Links
National Radio Astronomy Observatory (NRAO)
Robert C. Byrd Green Bank Telescope (GBT)
Harvard-Smithsonian Center for Astrophysics (CfA)
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


First Pulsar Detection With LOFAR Station
Dwingeloo, Holland (SPX) Jul 18, 2007
Astronomers from ASTRON and the University of Amsterdam successfully detected the pulsar PSR B0329+54 using the first LOFAR station, CS-01. The measurement took 15 minutes and used six of the prototype High Band Antennas (HBAs) that were recently installed at the "Core Station 1" field in Exloo, Drenthe, The Netherlands.







  • Congress Examines Challenges Facing Shuttle And Station Programs
  • Space Adventures Secures Seats On The Soyuz
  • Washington Conference To Examine Impact Of Civilian Space Travel On Culture And Economy
  • First Malaysian Astronaut To Take Off For Space Station October 10

  • Digging Deep For Martian Life
  • Creating Martian Clay
  • Opportunity Calls Home After Some Solar Juice Cranks Up The Batteries
  • NASA Robots Practice Moon Survey In The Arctic Circle

  • Russian Space Firm Signs 14 Deals For Commercial Rocket Launches
  • Spaceway 3 Is Delivered To The Spaceport For Its Mid-August Ariane 5 Launch
  • Sea Launch To Resume Zenit Launches In October
  • Russia Proton-M Booster Puts US Satellite Into Orbit

  • Campaign Prepares For Future Land-Surface Monitoring
  • DMCii Wins ESA Satellite Imaging Contract
  • Envisat Captures Breath Of Volcano
  • NASA Awards Contract For Land-Imaging Instrument

  • Charon: An Ice Machine In The Ultimate Deep Freeze
  • New Horizons Slips Into Electronic Slumber
  • Nap Before You Sleep For Your Cruise Into The Abyss Of Outer Sol
  • The Dwarf Planet Known As Eris Is More Massive Than Pluto

  • Interstellar Chemistry Gets More Complex With New Charged-Molecule Discovery
  • First Pulsar Detection With LOFAR Station
  • Astronomers Find The Most Distant Known Galaxies
  • The Gobbling Dwarf That Exploded

  • Throttling Back To The Moon
  • Moonshine Can Reflect Lunar Composition
  • Northrop Grumman Helps NASA Shape Plans For Affordable Lunar Lander
  • Summer Moon Illusion

  • Navtrak GPS Fleet Tracking Services Added To InfoLogix Mobility Solution Suite
  • Nokia Makes Finding Yourself Faster With New A-GPS Service
  • Poplar Creek Installs ProLink ProStar GPS To Enhance Golfer Experience And Deliver Advertising Revenues
  • SANYO Easy Street Portable Navigation Systems Make Their Debut

  • 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