. 24/7 Space News .
Hyperfast Star HE 0437-5439 Proven To Be Alien

The Large Magellanic Cloud where a rouge star is believed to have been ejected from.
by Staff Writers
Washington DC (SPX) Jan 29, 2008
A young star is speeding away from the Milky Way so fast that astronomers have been puzzled by where it came from; based on its young age it has traveled too far to have come from our galaxy.

Now by analyzing its velocity, light intensity, and for the first time its tell-tale elemental composition, Carnegie astronomers Alceste Bonanos and Mercedes Lopez-Morales, and collaborators Ian Hunter and Robert Ryans from Queen's University Belfast have determined that it came from our neighboring galaxy, the Large Magellanic Cloud (LMC).

The result suggests that it was ejected from that galaxy by a yet-to-be-observed massive black hole. The research will be published in an upcoming issue of the Astrophysical Journal Letters.

The star, dubbed HE 0437-5439, is an early-type star and one of ten so-called hypervelocity stars so far found speeding away from the Milky Way. "But this one is different from the other nine," commented Lopez-Morales. "Their type, speed, and age make them consistent with having been ejected from the center of our galaxy, where we know there is a super-massive black hole. This star, discovered in 2005, initially appeared to have an elemental makeup like our Sun's, suggesting that it, too, came from the center of our galaxy. But that didn't make sense because it would have taken 100 million years to get to its location, and HE 0437-5439 is only 35 million years old."

To explain the enigma, or "paradox of youth," the discoverers proposed that HE 0437-5439 was either a so-called blue straggler-a relatively young, massive star resulting from the merger of two low-mass stars from the Milky Way, or it originated from the Large Magellanic Cloud.

"We were intrigued by the conundrum and decided to take up the challenge to solve this," stated Bonanos. "Stars in the LMC are known to have lower elemental abundances than most stars in our galaxy, so we could determine if its chemistry was more like that galaxy's or our own."

The team confirmed results of the previous study concerning the mass, age, and speed of the star. It is about nine times the mass of our Sun, about 35 million years old, and it is zooming away from the Milky Way and Large Magellanic Cloud into intergalactic space at 1.6 million miles per hour (2.6 million km/hour).

Although the previous study was able to roughly estimate the star's elemental composition, the measurements were not detailed enough to determine if the elements match stars in our galaxy, or are characteristic of stars from the Large Magellanic Cloud. These astronomers were able to measure the relative abundances of certain elements for the first time in any hypervelocity star. The relative abundance of key elements tells them where a star originated.

"We've ruled out that the star came from the Milky Way," explained Bonanos. "The concentration of elements in Large Magellanic Cloud stars are about half those in our Sun. Like evidence from a crime scene, the fingerprints point to an origin in the Large Magellanic Cloud."

Based on the speed of the star's rotation measured by the discoverers, and confirmed by this team, the astronomers believe that the star was originally part of a binary system. The binary could have passed close to a black hole 1,000 the mass of the Sun. As one star was pulled into the black hole, the other was whipped into frenzy and flung out of the galaxy.

"This is the first observational clue that a massive black hole exists somewhere in the LMC. We look forward to finding out where this black hole might be," concluded Bonanos.

Community
Email This Article
Comment On This Article

Related Links
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


Unusual Supernovae May Reveal Intermediate-Mass Black Holes In Globular Clusters
Santa Cruz CA (SPX) Jan 30, 2008
A strange and violent fate awaits a white dwarf star that wanders too close to a moderately massive black hole. According to a new study, the black hole's gravitational pull on the white dwarf would cause tidal forces sufficient to disrupt the stellar remnant and reignite nuclear burning in it, giving rise to a supernova explosion with an unusual appearance. Observations of such supernovae could confirm the existence of intermediate-mass black holes, currently the subject of much debate among astronomers.







  • Innovative Tools For An Out-Of-This-World Job
  • Exploring The Cosmos With NASA Space Braille
  • SKorea research institute forges ties with NASA: official
  • NASA astronauts report good communications

  • Lyell Panorama Inside Victoria Crater Mars Four Years On Mars
  • Traces Of The Martian Past In The Terby Crater
  • HiRISE Camera Details Dynamic Wind Action On Mars
  • Ice Clouds Put Mars In The Shade

  • TEXUS Research Rockets To Launch On 31 January And 7 February 2008
  • Russian space center to launch boosters
  • Antrix Launches Israeli Satellite Using Commercial PSLV Rocket
  • Russia To Launch Two Telecom Satellites On Jan 28 And Feb 10

  • New Radar Satellite Technique Sheds Light On Ocean Current Dynamics
  • SPACEHAB Subsidiary Wins NASA Orbiting Carbon Observatory Contract
  • Radical New Lab Fights Disease Using Satellites
  • SKorea decides to terminate satellite: space agency

  • ASU Research Solves Solar System Quandary
  • Happy Second Birthday New Horizons
  • The PI's Perspective: Autumn 2007: Onward to the Kuiper Belt
  • Data For The Next Generations

  • Hyperfast Star HE 0437-5439 Proven To Be Alien
  • Unusual Supernovae May Reveal Intermediate-Mass Black Holes In Globular Clusters
  • Cosmic Suburbia Is A Better Breeding Ground For Stars
  • X-rays Betray Giant Particle Accelerator In The Sky

  • Volcanic deposits may aid lunar outposts
  • NG-Built Antennas Helping Provide Data On Moon's Thermal History For Japan's KAGUYA (SELENE) Mission
  • Amateur Radio Operators Asked To Tune Into Lunar Radar Bounce
  • With Moon Dirt In Demand, Geoscientist's Business Is Booming

  • Savi Technology And AVAANA Deliver RFID Supply Chain Solutions To India Market
  • First Deputy PM Ivanov Slams Agency Over Glonass Failings
  • Lockheed Martin-Built GPS Satellites Pass 75 Year Mark Of Combined On-Orbit Operations
  • Integral Systems Awarded Contract For GPS Next Gen Control Segment

  • 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