Science Current Events | Science News | Brightsurf.com
 

Honing in on supernova origins

May 08, 2012

Pasadena, CA-Type Ia supernovae are important stellar phenomena, used to measure the expansion of the universe. But astronomers know embarrassingly little about the stars they come from and how the explosions happen. New research from a team led by Harvard University and including Carnegie's Josh Simon, Chris Burns, Nidia Morrell, and Mark Phillips examined 23 Type Ia supernovae and helped identify the formation process for at least some of them. Their work will be published in The Astrophysical Journal and is available online.

Type Ia supernovae are violent stellar explosions. Observations of their brightness are used to determine distances in the universe and have shown scientists that the universe is expanding at an accelerating rate. The Nobel Prize in Physics was awarded December 10, 2011, to three astronomers for their "discovery of the accelerating expansion of the Universe through observations of distant supernovae."

Type Ia supernovae are believed to be thermonuclear explosions of a white dwarf star that's part of a binary system--two stars that are physically close together and orbit around a common center of mass. But there are two different possibilities for how Type Ia supernovae are created from this type of binary system.

In the so-called double-degenerate model, the orbit between two white dwarf stars gradually shrinks until the lighter star gets so close to its companion that it is ripped apart by tidal forces. Some of the lighter star's matter is then absorbed into the primary white dwarf, causing an explosion. In the competing single-degenerate model, the white dwarf slowly accretes mass from an ordinary, non-white dwarf star, until it reaches an ignition point.

"Previous studies have produced conflicting results. The conflict disappears if both types of explosion are happening," explained lead author Ryan Foley of the Harvard-Smithsonian Center for Astrophysics.

The research team studied 23 Type Ia supernovae to look for signatures of gas around the supernovae, which should be present only in single-degenerate systems. They found that the more powerful explosions tended to come from "gassy" systems, or systems with outflows of gas. However, only a fraction of supernovae show evidence for outflows--the remainder likely come from double-degenerate systems.

This finding has important implications for how astronomers use supernovae to measure the universe's expansion. "To maximize the accuracy of our measurements we may have to separate the two kinds of Type Ia supernovae," Simon said. "This study gives us one potential way to tell them apart."

###

Funding for this research was provided in part by a Clay Fellowship, the ISF, the Minerva foundations, an ARCHES award, the Lord Sieff of Brimpton Fund, a Minerva fellowship, CONICYT, the Millennium Center for Supernova Science, and the NSF

The HET is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universitat Munchen, and Georg-August-Universitat Gottingen. The HET is named in honor of its principal benefactors, William P. Hobby and Robert E. Eberly.

The Carnegie Institution for Science (carnegiescience.edu) is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

Carnegie Institution


Related Supernova Current Events and Supernova News Articles


A beautiful instance of stellar ornamentation
In this image from ESO's Very Large Telescope (VLT), light from blazing blue stars energises the gas left over from the stars' recent formation.

Proof that ancient supernovae zapped Earth sparks hunt for after effects
Two new papers appearing in the journal Nature this week are "slam-dunk" evidence that energies from supernovae have buffeted our planet, according to astrophysicist Adrian Melott of the University of Kansas.

Gravitational wave search provides insights into galaxy evolution and mergers
New results from NANOGrav - the North American Nanohertz Observatory for Gravitational Waves - establish astrophysically significant limits in the search for low-frequency gravitational waves.

Magnetar could have boosted explosion of extremely bright supernova
Calculations by scientists have found highly magnetized, rapidly spinning neutron stars called magnetars could explain the energy source behind two extremely unusual stellar explosions.

Tiny, ancient galaxy preserves record of catastrophic event
The lightest few elements in the periodic table formed minutes after the Big Bang. Heavier chemical elements are created by stars, either from nuclear fusion in their interiors or in catastrophic explosions.

Caught for the first time: The early flash of an exploding star
NASA's planet hunter, the Kepler space telescope, has captured the brilliant flash of an exploding star's shock wave--what astronomers call the "shock breakout" of a supernova--for the first time in visible light wavelengths.

Caught in the act: UW astronomers find a rare supernova 'impostor' in a nearby galaxy
Breanna Binder, a University of Washington postdoctoral researcher in the Department of Astronomy and lecturer in the School of STEM at UW Bothell, spends her days pondering X-rays.

Examining how terrestrial life's building blocks may have first formed
How did life begin? This is one of the most fundamental questions scientists puzzle over. To address it, they have to look not just back to the primordial Earth, but out into space. Now, scientists propose in the Journal of the American Chemical Society a new set of cosmic chemical reactions that could have contributed to the formation of life on our planet.

A violent wind blown from the heart of a galaxy tells the tale of a merger
An international team led by a researcher from Hiroshima University has succeeded in revealing the detailed structure of a massive ionized gas outflow streaming from the starburst galaxy NGC 6240.

The Milky Way's clean and tidy galactic neighbor
IC 1613 is a dwarf galaxy in the constellation of Cetus (The Sea Monster). This VST image shows the galaxy's unconventional beauty, all scattered stars and bright pink gas, in great detail.
More Supernova Current Events and Supernova News Articles

Supernova (The Lightless Trilogy)

Supernova (The Lightless Trilogy)
by C.A. Higgins (Author)


C. A. Higgins’s acclaimed novel Lightless fused suspenseful storytelling, high-caliber scientific speculation, and richly developed characters into a stunning science fiction epic. Now the dazzling Supernova heightens the thrills and deepens the haunting exploration of technology and humanity—and the consequences that await when the two intersect.

Once Ananke was an experimental military spacecraft. But a rogue computer virus transformed it—her—into something much more: a fully sentient artificial intelligence, with all the power of a god—and all the unstable emotions of a teenager.
 
Althea, the ship’s engineer and the last living human aboard, nearly gave her life to save Ananke from dangerous saboteurs, forging a bond as powerful as that between mother and...

The Supernova Advisor: Crossing the Invisible Bridge to Exceptional Client Service and Consistent Growth

The Supernova Advisor: Crossing the Invisible Bridge to Exceptional Client Service and Consistent Growth
by Rob Knapp (Author)


The Supernova Model is a client service, client acquisition, and practice management model that drives an explosive acceleration in revenue and client satisfaction by capitalizing upon the 80/20 Rule. First implemented by financial advisors at Merrill Lynch—under the leadership of author Rob Knapp—it has grown increasingly popular within the financial services industry. The Supernova Advisor skillfully outlines this proven model and reveals how it can be used to create an exceptional experience for your clients, while significantly growing your business.

SuperNova: Heroes of Arcania

SuperNova: Heroes of Arcania


Sometimes the villain must create the hero.
The streets of Arcania are overrun with crime, deteriorating as a madman named Fortune makes himself at home. He shows no mercy, striking down anyone in his path – including Nova Benson’s little sister. Devastated, Nova vows to seek justice for her family, but aside from her freak strength and impenetrable skin, how is she supposed to stop a monster like Fortune?

Cole Warner wants to help people. Entrusted to keep his family’s secret, he’s also frustrated at having to hide his gift. He knows he could do more to help in the fight against Fortune. If he could convince his sister Penelope to join him, they might even have a chance at beating him. When Cole meets Nova, he realizes his whole world is about to change. And...

Supernova

Supernova


Nick Miller lives an ordinary life in his hometown of Bakersville. That is, until he starts to notice strange occurrences that seem to be indicative of a sinister cover-up. In a few seconds, his life and the future of civilization on Earth are altered forever by a deadly burst of light from space. This is the story of one man’s struggle to survive, and his ultimate triumph in the face of a tyrannical faction.

Supernova

Supernova
by Braxton A. Cosby (Author)


WHAT YOU CHOOSE, BECOMES YOU... Against everything he had known as truth, William has made the choice to protect Sydney from the forces seeking to destroy her. But just as these two Star-Crossed lovers are beginning to explore their relationship and search for answers to the mysteries of Sydney's existence, she advances to the next stage of her Star-child evolution--Supernova--and struggles not only to control her new powers, but also the emotions for her new love. William seeks to find the truth behind Sydney's erratic behavior, while overcoming the new threat headed to Earth to destroy them. With new villains and old allies on the horizon, and chaos brewing on William's home world, will self-sacrifice prove to be the only way for him to achieve victory and defend his...

Supernova

Supernova
by Georgia Chioni


Mor and Taurous are two chief space scientists on planet Neuron. They’re occupied for many years on the secret to unlocking a passage between parallel universes. Their work is based on a map of gravitational echoes that implies the existence of parallel universes. They’re currently perfecting a device that can create a sxism, enabling the passage between universes. However, before the final trial, they are informed that a comet has deviated from its course, and will destroy Neuron on impact. Their planet falls into chaos, as its inhabitants fight for their lives by escaping Neurone by any means possible. Taurous takes control of the device by force, and escapes to a parallel universe. Just before the comet hits Neouron, Mor uses the device himself to escape. He wakes up on a...

Supernova: The Knight, the Princess and the Falling Star

Supernova: The Knight, the Princess and the Falling Star
by Dewi Lestari (Author), Harry Aveling (Translator)


Supernova: The Knight, The Princess and the Falling Star presents a series of intertwined and unconventional love stories, straight and gay, with a bit of science and spirituality added to the mix. The major characters are young, urban, and technologically highly aware. They are caught up in major forms of contemporary social conflict. The work has been highly acclaimed. The poet Taufiq Ismail has written: "A renewal has taken place in Indonesian literature over the past decade. Supernova is an intelligent, unique and truly exciting exploration of science, spirituality and the nature of love." The literary critic Jacob Soemardjo suggests: "This is an attractive novel by a young writer. It is an intellectual work in the form of a work of pop art, set in the real world. It opposes old...

Supernova

Supernova
by C. L. Parker (Author)


Somewhere between the first twinkling of stars in the night sky and the break of dawn, two souls from two unique worlds collide, creating an everlasting supernova. Kerrigan Cruz and Dominic Grayson are among the chosen few who have the gift, or the curse, of being able to walk between two worlds. It is on the cusp of where these beings meet that everything changes, and life as they know it is turned upside down. Fantasy becomes reality and what shouldn't be, is. Forced by destiny, their chance encounter is breathed to life by the one thing that can make even the most impossible of impossibilities a reality. Something so complex in nature, yet as simple as a flicker of thought to exercise. Most normal people go about their everyday lives never even suspecting its existence. But it is...

Summer of Supernovas

Summer of Supernovas
by Darcy Woods (Author)


“This sweet summer romance will have you flipping the pages all night long!”—Bustle
 
Fans of Jennifer E. Smith and Jenny Han will fall in love with this heartfelt and humor-laced debut following one zodiac-obsessed teen as she struggles to find the guy of her cosmic dreams.
 
As the daughter of an expert astrologer, Wilamena Carlisle knows the truth lies within the stars. So when she discovers a planetary alignment that won’t repeat for a decade, she’s forced to tackle her greatest astrological fear: The Fifth House—relationships and love.
 
But Wil must decide whether to trust her heart or her chart when she falls for a sensitive guitar player whose zodiac sign points to cosmic disaster.
 
If Wil’s fate is truly written in the stars,...

Champagne Supernovas: Kate Moss, Marc Jacobs, Alexander McQueen, and the '90s Renegades Who Remade Fashion

Champagne Supernovas: Kate Moss, Marc Jacobs, Alexander McQueen, and the '90s Renegades Who Remade Fashion
by Maureen Callahan (Author)


“Terrifically exciting and fun” (Publishers Weekly), Champagne Supernovas is “a lucid, smoothly executed look at a pivotal decade in the legacy of American fashion” (Kirkus Reviews) as told through the lives of Kate Moss, Marc Jacobs, and Alexander McQueen—the three iconic personalities who defined the time.

Veteran pop culture journalist Maureen Callahan takes us back to the pivotal style moment of the early 1990s—when supermodel glamazons gave way to heroin chic, when the alternative became the mainstream, and when fashion suddenly became the cradle for the most exciting artistic and cultural innovations of the age. Champagne Supernovas gives you the inside scoop from a bevy of supermodels, stylists, editors, photographers, confidantes, club kids, and scenesters who...

© 2016 BrightSurf.com