Though several models predict this behavior and evidence from supernovae points in this direction, actually observations of such pre-explosion outbursts have been rare. In new research led by Dr. Eran Ofek of the Weizmann Institute, scientists found such an outburst taking place a short time – just one month – before a massive star underwent a supernova explosion.
The findings, which recently appeared in Nature, help to clarify the series of events leading up to the supernova, as well as providing insight into the processes taking place in the cores of such massive stars as they progress toward the final stage of their lives.
Ofek, a member of the Institute's Particle Physics and Astrophysics Department, is a participant in the Palomar Transient Factory (PTF) project (led by Prof. Shri Kulkarni of the California Institute of Technology), which searches the skies for supernova events using telescopes at the Palomar Observatory in California. He and a research team from Israel, the UK and the US decided to investigate whether outbursts could be connected to later supernovae by combing for evidence of them in observations that predated PTF supernova sightings, using tools developed by Dr. Mark Sullivan of the University of Southampton.
The fact that they found such an outburst occurring just a little over a month before the onset of the supernova explosion was something of a surprise, but the timing and mass of the ejected material helped them to validate a particular model that predicts this type of pre-explosion event. A statistical analysis showed that there was only a 0.1% chance that the outburst and supernova were unrelated occurrences.
The exploding star, known as a type IIn supernova, began as a massive star, at least 8 times the mass of our sun. As such a star ages, the internal nuclear fusion that keeps it going produces heavier and heavier elements – until its core is mostly iron. At that point, the weighty core quickly collapses inward and the star explodes.
The violence and mass of the pre-explosion outburst they found, says Ofek, point to its source in the star's core. The material is speedily ejected from the core straight through the star's surface by the excitation of gravity waves. The researchers believe that continued research in this direction will show such mini-explosions to be the rule for this type of supernova.
Also participating in this research were Prof. Avishay Gal-Yam, Dr. Ofer Yaron and Iair Arcavi of the Institute's Particle Physics and Astrophysics Department, and Prof. Nir Shaviv of the Hebrew University of Jerusalem.
Prof. Avishay Gal-Yam's research is supported by the Helen and Martin Kimmel Award for Innovative Investigation; the Nella and Leon Benoziyo Center for Astrophysics; and the Lord Sieff of Brimpton Memorial Fund.
Dr. Eran Ofek's research is supported by the Willner Family Leadership Institute. Dr. Ofek is the incumbent of the Arye and Ido Dissentshik Career Development Chair.
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,700 scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.
Weizmann Institute news releases are posted on the World Wide Web at http://wis-wander.weizmann.ac.il, and are also available at http://www.eurekalert.org.
Yivsam Azgad | EurekAlert!
Active pits on Rosetta’s comet
03.07.2015 | Max Planck Institute for Solar System Research, Göttingen
Researchers find the macroscopic Brownian motion phenomena of self-powered liquid metal motors
02.07.2015 | Science China Press
Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.
The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...
New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions
A new technique pioneered at the U.S. Department of Energy's Brookhaven National Laboratory reveals atomic-scale changes during catalytic reactions in real...
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...
A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...
The three-year clinical trial results of the retinal implant popularly known as the "bionic eye," have proven the long-term efficacy, safety and reliability of...
25.06.2015 | Event News
16.06.2015 | Event News
11.06.2015 | Event News
03.07.2015 | Press release
03.07.2015 | Agricultural and Forestry Science
03.07.2015 | Health and Medicine