Featured Research

from universities, journals, and other organizations

Blast From The Past: Farthest Supernova Ever Seen Sheds Light On Dark Universe

Date:
April 3, 2001
Source:
Space Telescope Science Institute
Summary:
NASA's Hubble Space Telescope has seen a burst of light from an exploding star located much farther from Earth than any previously seen - a supernova blast in the early universe that is casting light on a mystery of truly cosmic scale.

NASA's Hubble Space Telescope has seen a burst of light from an exploding star located much farther from Earth than any previously seen - a supernova blast in the early universe that is casting light on a mystery of truly cosmic scale.

Related Articles


This stellar explosion is extraordinary not only because of its tremendous distance, 10 billion light-years from Earth, but also because its discovery greatly bolsters the case for the existence of a mysterious form of "dark energy" pervading the universe. The concept of dark energy, which shoves galaxies away from each other at an ever-increasing speed, was first proposed, and then discarded, by Albert Einstein early in the last century.

The Hubble discovery also reinforces the startling idea that the universe only recently began speeding up, a discovery made about three years ago when the unusually dim light of several distant supernovas suggested the universe is expanding more quickly than in the past, but there were alternate explanations. The more distant supernova (redshift z=1.7) refutes these alternatives and offers the first tantalizing observational evidence that gravity began slowing down the expansion of the universe after the big bang. Only later did the repulsive force of dark energy win out over gravity's attractive grip.

"The supernova appears to be one of a special class of explosions that allows astronomers to understand how the universe's expansion has changed over time, much as the way a parent follows a child's growth spurts by marking a doorway," said Adam Riess of the Space Telescope Science Institute (STScI), Baltimore, MD. "This supernova shows us the universe is behaving like a driver who slows down approaching a red stoplight and then hits the accelerator when the light turns green." The team of astronomers, led by Riess, made the discovery by analyzing hundreds of images taken by Hubble in infrared and visible light to study how galaxies formed. Fortuitously, one of those galaxies contained a supernova previously discovered by astronomers Ron Gilliland, STScI, and Mark Phillips, Carnegie Institutions of Washington.

The record-breaking supernova appears brighter than it should if the universe had been expanding at a steady rate. The reason is that a decelerating universe holds galaxies relatively close together and objects in them would have appeared brighter because they would be closer. "Long ago, when the light left this distant supernova, the universe may have been slowing down due to the mutual tug of all the mass in the universe," said Riess. "Billions of years later, when the light left more recent supernovas, the universe had begun accelerating, stretching the expanse between galaxies and making objects in them appear dimmer."

"Hubble's ability to find titanic stellar explosions at these extreme distances is what it takes to confirm this theory that the universe must have been slowing down before it switched into high gear,'" said Dr. Anne Kinney, director of NASA's Origins program at NASA Headquarters, Washington, DC. "Later this year Astronauts will install a new camera on Hubble that will give us 10 times better resolution than the current camera, which will give us an even better capability to find answers to grand cosmic questions like this."

Observations of several distant supernovas by two teams of astronomers in 1998 led to the prediction that the universe got the "green light" to accelerate when it was half its present age. Astronomers say the new Hubble findings rule out other explanations.

Nearly a century ago, Albert Einstein's Law of General Relativity concluded the universe must collapse under the relentless pull of gravity. However, like many scientists of his time, he assumed the universe to be static and unchanging. To make his equations fit those observations, Einstein added something he called the "cosmological constant" whose gravity is repulsive, though he had no idea if it was real.

Shortly afterwards, astronomer Edwin Hubble made the celebrated discovery that the universe was expanding. He assumed that the universe must be slowing down under gravity and might even come to a halt, leading Einstein later to say that his cosmological constant was the biggest blunder of his career. Now it appears Einstein was on the right track after all.

The source of the repulsive gravity may be something akin to Einstein's cosmological constant, referred to as the energy of the "quantum vacuum," a subatomic netherworld pervading space that provides a source of energy, or it may be something entirely new and unexpected. "While we don't know what dark energy is, we are certain that understanding it will provide crucial clues in the quest to unify the forces and particles in the universe, and that the route to this understanding involves telescopes, not accelerators," said astrophysicist Michael Turner of the University of Chicago.

Riess’ collaborators include Peter Nugent (Lawrence Berkeley National Laboratory), Brian Schmidt (Mount Stromlo Observatory), and John Tonry (Institute for Astronomy). NASA’s Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency.


Story Source:

The above story is based on materials provided by Space Telescope Science Institute. Note: Materials may be edited for content and length.


Cite This Page:

Space Telescope Science Institute. "Blast From The Past: Farthest Supernova Ever Seen Sheds Light On Dark Universe." ScienceDaily. ScienceDaily, 3 April 2001. <www.sciencedaily.com/releases/2001/04/010403070934.htm>.
Space Telescope Science Institute. (2001, April 3). Blast From The Past: Farthest Supernova Ever Seen Sheds Light On Dark Universe. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2001/04/010403070934.htm
Space Telescope Science Institute. "Blast From The Past: Farthest Supernova Ever Seen Sheds Light On Dark Universe." ScienceDaily. www.sciencedaily.com/releases/2001/04/010403070934.htm (accessed October 26, 2014).

Share This



More Space & Time News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: China Launches Moon Orbiter

Raw: China Launches Moon Orbiter

AP (Oct. 24, 2014) China launched an experimental spacecraft Friday to fly around the moon and back to Earth in preparation for the country's first unmanned return trip to the lunar surface. (Oct. 24) Video provided by AP
Powered by NewsLook.com
China Prepares Unmanned Mission To Lunar Orbit

China Prepares Unmanned Mission To Lunar Orbit

Newsy (Oct. 23, 2014) The mission is China's next step toward automated sample-return missions and eventual manned missions to the moon. Video provided by Newsy
Powered by NewsLook.com
Russian Cosmonauts Kick Off Final Spacewalk of 2014

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Reuters - US Online Video (Oct. 22, 2014) Russian cosmonauts Maxim Suraev and Alexander Samokutyaev step outside the International Space Station to perform work on the exterior of the station's Russian module. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins