Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Closest, brightest supernova in decades is also a little weird

27.02.2014

Faster brightening than expected may typify cosmic yardstick Type Ia supernovae

A bright supernova discovered only six weeks ago in a nearby galaxy is provoking new questions about the exploding stars that scientists use as their main yardstick for measuring the universe.


This image features a color composite of SN 2014J in the 'cigar galaxy' M82, 11.4 million light years away, made from KAIT images obtained through several different filters. The supernova is marked with an arrow. Other round objects are relatively nearby stars in our own Milky Way Galaxy.

Credit: W. Zheng and A. Filippenko, University of California Berkeley

Called SN 2014J, the glowing supernova was discovered by a professor and his students in the United Kingdom on Jan. 21, about a week after the stellar explosion first became visible as a pinprick of light in its galaxy, M82, 11.4 million light years away. Still visible today through small telescopes in the Big Dipper, it is the brightest supernova seen from Earth since SN1987A, 27 years ago, and may be the closest Type Ia supernova – the kind used to measure cosmic distances – in more than 77 years.

When University of California, Berkeley, astronomer Alex Filippenko's research team looked for the supernova in data collected by the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory near San Jose, Calif., they discovered that the robotic telescope had actually taken a photo of it 37 hours after it appeared, unnoticed, on Jan. 14.

Combining this observation with another chance observation by a Japanese amateur astronomer, Filippenko's team was able to calculate that SN 2014J had unusual characteristics – it brightened faster than expected for a Type Ia supernova and, even more intriguing, it exhibited the same unexpected, rapid brightening as another supernova that KAIT discovered and imaged last year – SN 2013dy.

"Now, two of the three most recent and best-observed Type Ia supernovae are weird, giving us new clues to how stars explode," said Filippenko, referring to a third, though apparently 'normal,' Type Ia supernova, SN 2011fe, discovered three years ago. "This may be teaching us something general about Type Ia supernovae that theorists need to understand. Maybe what we think of as 'normal' behavior for these supernovae is actually unusual, and this weird behavior is the new normal."

A paper describing the SN 2014J observations – the first published on this newly discovered supernova – was posted online this week by The Astrophysical Journal Letters and will appear in the March 1 print issue.

Type Ia supernovae as standard candles

Astronomers noticed decades ago that Type Ia supernovae explode with about the same brightness, no matter where they are in the universe. This makes them good "standard candles" with which to judge distance. In the 1990s, two teams (both of them included Filippenko) used Type Ia supernovae to determine the distances to galaxies, compared distance with velocity and discovered that the universe is expanding faster and faster, rather than slowing down as expected. The teams' leaders, including UC Berkeley astrophysicist Saul Perlmutter, shared the 2011 Nobel Prize in Physics for this discovery.

While the latest discoveries do not contradict these results, refinements in understanding Type Ia explosions could help improve distance measurements and lead to more precise calculations of the expansion rate of the universe, thereby setting constraints on the nature of "dark energy," a still mysterious energy comprising 70 percent of the universe and thought to be responsible for its acceleration.

The new data also provide information about the physics occurring in the core of the explosion.

A Type Ia supernova is thought to be the explosion of a white dwarf – an old and very dense star that has shrunk from the size of the Sun to the size of Earth. When a white dwarf has a stellar companion, it can sometimes gain matter from it until the white dwarf becomes unstable, completely obliterating itself through a gigantic nuclear explosion.

New telescopes to catch more supernovae

Because of the importance of supernovae in measuring the universe, many new telescopes, such as the Palomar Transient Factor in San Diego County and the Pan-STARRS in Hawaii, continually rescan the sky to discover more of them. The KAIT telescope has a smaller field of view than newer ones do, so Filippenko's team has switched its focus to discovering supernovae earlier: it scans the same patches of sky every night or every other night. The sooner a new explosion is discovered, the sooner astronomers can capture information, such as spectra showing how the supernova brightens in different colors or wavelengths.

Last year, for example, KAIT and Filippenko's Lick Observatory Supernova Search (LOSS) team discovered and photographed SN 2013dy within two and a half hours of its appearance, earlier than for any other Type Ia. KAIT, which is operated by postdoctoral scholar WeiKang Zheng, is programmed to automatically take images of likely supernovae in five different wavelength bands, and in 2012 captured one supernova, SN 2012cg, three minutes after its discovery.

"Very, very early observations give us the most stringent constraints on what the star's behavior really is in the first stages of the explosion, rather than just relying on theoretical speculation or extrapolating back from observations at later times, which is like observing adolescents to understand early childhood," Filippenko said.

Filippenko's colleagues include Zheng; UC Berkeley graduate student Isaac Shivvers; assistant specialist Kelsey I. Clubb; postdoctoral scholars Ori D. Fox, Melissa L. Graham, Patrick L. Kelly and Jon C. Mauerhan; and amateur astronomer Koichi Itagaki of the Itagaki Astronomical Observatory in Yamagata, Japan, who captured an image of SN 2014J just 20 hours after it exploded.

The research was funded by the TABASGO Foundation, the Sylvia & Jim Katzman Foundation, the Christopher R. Redlich Fund, Gary and Cynthia Bengier, the Richard and Rhoda Goldman Fund, Weldon and Ruth Wood, and the National Science Foundation.

Robert Sanders | EurekAlert!

More articles from Physics and Astronomy:

nachricht NASA scientist suggests possible link between primordial black holes and dark matter
25.05.2016 | NASA/Goddard Space Flight Center

nachricht The dark side of the fluffiest galaxies
24.05.2016 | Instituto de Astrofísica de Canarias (IAC)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

Im Focus: Transparent - Flexible - Printable: Key technologies for tomorrow’s displays

The trend-forward world of display technology relies on innovative materials and novel approaches to steadily advance the visual experience, for example through higher pixel densities, better contrast, larger formats or user-friendler design. Fraunhofer ISC’s newly developed materials for optics and electronics now broaden the application potential of next generation displays. Learn about lower cost-effective wet-chemical printing procedures and the new materials at the Fraunhofer ISC booth # 1021 in North Hall D during the SID International Symposium on Information Display held from 22 to 27 May 2016 at San Francisco’s Moscone Center.

Economical processing

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

LZH shows the potential of the laser for industrial manufacturing at the LASYS 2016

25.05.2016 | Trade Fair News

Great apes communicate cooperatively

25.05.2016 | Life Sciences

Thermo-Optical Measuring method (TOM) could save several million tons of CO2 in coal-fired plants

25.05.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>