Featured Research

from universities, journals, and other organizations

Astronomers see historical supernova from a new angle

Date:
March 31, 2010
Source:
Harvard-Smithsonian Center for Astrophysics
Summary:
Our telescopes show the Milky Way galaxy only as it appears from one vantage point: our solar system. Now, using a simple but powerful technique, astronomers have seen an exploding star or supernova from several angles.

Chandra X-ray Observatory image of the supernova remnant Cassiopeia A (Cas A). The red, green, and blue regions in this X-ray image of Cas A show where the intensity of low, medium, and high-energy X-rays, respectively, is greatest. While this photo shows the remains of the exploded star, light echoes show us reflected light from the explosion itself.
Credit: NASA/CXC/MIT/UMass Amherst/M.D.Stage et al.

Since Galileo first pointed a telescope at the sky 400 years ago, a myriad of technological advances have allowed astronomers to look at very faint objects, very distant objects, and even light that's invisible to the human eye. Yet, one aspect usually remains out of reach -- the benefit of a 3-D perspective.

Our telescopes show the Milky Way galaxy only as it appears from one vantage point: our solar system. Now, using a simple but powerful technique, a group of astronomers led by Armin Rest of Harvard University has seen an exploding star or supernova from several angles.

"The same event looks different from different places in the Milky Way," said Rest. "For the first time, we can see a supernova from an alien perspective."

The supernova left behind the gaseous remnant Cassiopeia A. The supernova's light washed over the Earth about 330 years ago. But light that took a longer path, reflecting off clouds of interstellar dust, is just now reaching us. This faint, reflected light is what the astronomers have detected.

The technique is based on the familiar concept of an echo, but applied to light instead of sound. If you yell, "Echo!" in a cave, sound waves bounce off the walls and reflect back to your ears, creating echoes. Similarly, light from the supernova reflects off interstellar dust to the Earth. The dust cloud acts like a mirror, creating light echoes that come from different directions depending on where the clouds are located.

"Just like mirrors in a changing room show you a clothing outfit from all sides, interstellar dust clouds act like mirrors to show us different sides of the supernova," explained Rest.

Moreover, an audible echo is delayed since it takes time for the sound waves to bounce around the cave and back. Light echoes also are delayed by the time it takes for light to travel to the dust and reflect back. As a result, light echoing from the supernova can reach us hundreds of years after the supernova itself has faded away.

Not only do light echoes give astronomers a chance to directly study historical supernovae, they also provide a 3-D perspective since each echo comes from a spot with a different view of the explosion.

Most people think a supernova is like a powerful fireworks blast, expanding outward in a round shell that looks the same from every angle. But by studying the light echoes, the team discovered that one direction in particular looked significantly different than the others.

They found signs of gas from the stellar explosion streaming toward one point at a speed almost 9 million miles per hour (2,500 miles per second) faster than any other observed direction.

"This supernova was two-faced!" said Smithsonian co-author and Clay Fellow Ryan Foley. "In one direction the exploding star was blasted to a much higher speed."

Previous studies support the team's finding. For example, the neutron star created when the star's core collapsed is zooming through space at nearly 800,000 miles per hour in a direction opposite the unique light echo. The explosion may have kicked gas one way and the neutron star out the other side (a consequence of Newton's third law of motion, which states that every action has an equal and opposite reaction).

By combining the new light-echo measurements and the movement of the neutron star with X-ray data on the supernova remnant, astronomers have assembled a 3-D perspective, giving them new insight into the Cas A supernova.

"Now we can connect the dots from the explosion itself, to the supernova's light, to the supernova remnant," said Foley.

Cassiopeia A is located about 16,000 light-years from Earth and contains matter at temperatures of around 50 million degrees F, causing it to glow in X-rays. A 3-D computer model of the remnant is online.

The Mayall 4-meter telescope at Kitt Peak National Observatory was used to locate the light echoes. Follow-up spectra were obtained with the 10-meter Keck I Telescope.


Story Source:

The above story is based on materials provided by Harvard-Smithsonian Center for Astrophysics. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Rest, R. J. Foley, B. Sinnott, D. L. Welch, C. Badenes, A. V. Filippenko, M. Bergmann, W. A. Bhatti, S. Blondin, P. Challis, G. Damke, H. Finley, M. E. Huber, D. Kasen, R. P. Kirshner, T. Matheson, P. Mazzali, D. Minniti, R. Nakajima, G. Narayan, K. Olsen, D. Sauer, R. C. Smith, N. B. Suntzeff. Direct Confirmation of the Asymmetry of the Cas A SN Explosion with Light Echoes. Astrophysics, [link]

Cite This Page:

Harvard-Smithsonian Center for Astrophysics. "Astronomers see historical supernova from a new angle." ScienceDaily. ScienceDaily, 31 March 2010. <www.sciencedaily.com/releases/2010/03/100331104925.htm>.
Harvard-Smithsonian Center for Astrophysics. (2010, March 31). Astronomers see historical supernova from a new angle. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2010/03/100331104925.htm
Harvard-Smithsonian Center for Astrophysics. "Astronomers see historical supernova from a new angle." ScienceDaily. www.sciencedaily.com/releases/2010/03/100331104925.htm (accessed September 2, 2014).

Share This



More Space & Time News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: NASA Captures Solar Flare

Raw: NASA Captures Solar Flare

AP (Sep. 1, 2014) NASA reported the sun emitted a mid-level solar flare, on August 24th. NASA's Solar Dynamics Observatory captured the images of the flare, which erupted on the left side of the sun. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Space Shuttle Discovery's Legacy, 30 Years Later

Space Shuttle Discovery's Legacy, 30 Years Later

Newsy (Aug. 30, 2014) The space shuttle Discovery launched for the very first time 30 years ago. Here's a look back at its legacy. Video provided by Newsy
Powered by NewsLook.com
Experiment Tests Whether Universe Is Actually A Hologram

Experiment Tests Whether Universe Is Actually A Hologram

Newsy (Aug. 27, 2014) Researchers at Fermilab are using a device called "The Holometer" to test whether our universe is actually a 2-D hologram that just seems 3-D. Video provided by Newsy
Powered by NewsLook.com
SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. 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:
from the past week

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