Subscribe free to our newsletters via your
. 24/7 Space News .




STELLAR CHEMISTRY
Exiled stars explode far from home
by Staff Writers
Berkeley CA (SPX) Jun 05, 2015


This is an artist's concept of a Type Ia supernova exploding in the region between galaxies in a large cluster of galaxies, one of which is visible at the left. Image courtesy Dr. Alex H Parker, NASA and the SDSS.

Sharp images obtained by the Hubble Space Telescope confirm that three supernovae discovered several years ago exploded in the dark emptiness of intergalactic space, having been flung from their home galaxies millions or billions of years earlier. Most supernovae are found inside galaxies containing hundreds of billions of stars, one of which might explode per century per galaxy.

These lonely supernovae, however, were found between galaxies in three large clusters of several thousand galaxies each. The stars' nearest neighbors were probably 300 light years away, nearly 100 times farther than our sun's nearest stellar neighbor, Proxima Centauri, 4.24 light years distant.

Such rare solitary supernovae provide an important clue to what exists in the vast empty spaces between galaxies, and can help astronomers understand how galaxy clusters formed and evolved throughout the history of the universe.

The solitary worlds reminded study leader Melissa Graham, a University of California, Berkeley, postdoctoral fellow and avid sci-fi fan, of the fictional star Thrial, which, in the Iain Banks novel Against a Dark Background, lies a million light years from any other star. One of its inhabited planets, Golter, has a nearly starless night sky.

Any planets around these intracluster stars - all old and compact stars that exploded in what are called Type Ia supernovae - were no doubt obliterated by the explosions, but they, like Golter, would have had a night sky depleted of bright stars, Graham said. The density of intracluster stars is about one-millionth what we see from Earth.

"It would have been a fairly dark background indeed," she said, "populated only by the occasional faint and fuzzy blobs of the nearest and brightest cluster galaxies."

Graham and her colleagues - David Sand of Texas Tech University in Lubbock, Dennis Zaritsky of the University of Arizona in Tucson and Chris Pritchet of the University of Victoria in British Columbia - will report their analysis of the three stars in a paper to be presented Friday, June 5, at a conference on supernovae at North Carolina State University in Raleigh. Their paper has also been accepted by the Astrophysical Journal.

Clusters of thousands of galaxies
The new study confirms the discovery between 2008 and 2010 of three apparently hostless supernovae by the Multi-Epoch Nearby Cluster Survey using the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii.

The CFHT was unable to rule out a faint galaxy hosting these supernovae. But the sensitivity and resolution of images from the Hubble Space Telescope's Advanced Camera for Surveys are 10 times better and clearly show that the supernovae exploded in empty space, far from any galaxy. They thus belong to a population of solitary stars that exist in most if not all clusters of galaxies, Graham said

While stars and supernovae typically reside in galaxies, galaxies situated in massive clusters experience gravitational forces that wrench away about 15 percent of the stars, according to a recent survey. The clusters have so much mass, though, that the displaced stars remain gravitationally bound within the sparsely populated intracluster regions.

Once dispersed, these lonely stars are too faint to be seen individually unless they explode as supernovae. Graham and her colleagues are searching for bright supernovae in intracluster space as tracers to determine the population of unseen stars. Such information provides clues about the formation and evolution of large scale structures in the universe.

"We have provided the best evidence yet that intracluster stars truly do explode as Type Ia supernovae," Graham said, "and confirmed that hostless supernovae can be used to trace the population of intracluster stars, which is important for extending this technique to more distant clusters."

Graham and her colleagues also found that a fourth exploding star discovered by CFHT appears to be inside a red, round region that could be a small galaxy or a globular cluster. If the supernova is in fact part of a globular cluster, it marks the first time a supernova has been confirmed to explode inside these small, dense clusters of fewer than a million stars. All four supernovae were in galaxy clusters sitting about a billion light years from Earth.

"Since there are far fewer stars in globular clusters, only a small fraction of the supernovae are expected to occur in globular clusters," Graham said. "This might be the first confirmed case, and may indicate that the fraction of stars that explode as supernovae is higher in either low-mass galaxies or globular clusters."

Graham said that most theoretical models for Type Ia supernovae involve a binary star system, so the exploding stars would have had a companion throughout their lifetimes.

"This is no love story, though," she added. "The companion was either a lower-mass white dwarf that eventually got too close and was tragically fragmented into a ring that was cannibalized by the primary star, or a regular star from which the primary white dwarf star stole sips of gas from its outer layers. Either way, this transfer of material caused the primary to become unstably massive and explode as a Type Ia supernova."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of California - Berkeley
Stellar Chemistry, The Universe And All Within It






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




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





STELLAR CHEMISTRY
Distant radio galaxies reveal hidden structures right above our heads
Toronto, Canada (SPX) Jun 03, 2015
By observing galaxies billions of light-years away, a team of astronomers has detected tube-like structures mere hundreds of kilometres above the Earth's surface. "For over 60 years, scientists believed these structures existed but by imaging them for the first time, we've provided visual evidence that they are really there," said Cleo Loi of the ARC Centre of Excellence for All-sky Astrop ... read more


STELLAR CHEMISTRY
Crashing comets may explain mysterious lunar swirls

Google Lunar X-Prize meets Yoda

China, Russia plan joint landing on the Moon

NASA's LRO Moves Closer to the Lunar Surface

STELLAR CHEMISTRY
United Arab Emirates Hopes to Reach Mars by2021

NASA Begins Testing Next Mars Lander Insight

The Supreme Council of Parachute Experts

Science Drives NASA's Journey to Mars

STELLAR CHEMISTRY
NASA pushes flying saucer parachute test to Thursday

Keeping astronauts in space longer with better air and water

NASA to test supersonic parachute in flying saucer launch

McCarthy-Smith SPACE Act passes with broad bipartisan support

STELLAR CHEMISTRY
China Plans First Ever Landing On The Lunar Far Side

China ranked 4th among world space powers

3D printer making Chinese space suit parts

Xinhua Insight: How China joins space club?

STELLAR CHEMISTRY
Space Station remodelling

NASA Delays Approval on International Space Station Projects

Space age mice are thin-skinned

NASA Begins Major Reconfiguration of International Space Station

STELLAR CHEMISTRY
Recent Proton loss to push up launch costs warns manufacturer

Air Force Certifies SpaceX for National Security Space Missions

SpaceX cleared for US military launches

Ariane 5's second launch of 2015

STELLAR CHEMISTRY
Astronomers Discover a Young Solar System Around a Nearby Star

Circular orbits identified for small exoplanets

Weather forecasts for planets beyond our solar system

Astrophysicists offer proof that famous image shows forming planets

STELLAR CHEMISTRY
High-temperature superconductivity in atomically thin films

MUOS-3 communications satellite completes in-orbit testing

Spinning a new version of silk

ESA heading towards removing space debris




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.