supernovae tagged posts

A Hubble image of a field of distant galaxies. A new study of the gas content in galaxies so distant their light has been traveling for about ten billion years suggests that the processes converting gas into stars is about the same back then as in the local universe. NASA, ESA, G. Illingworth (UCO/Lick & UCSC), R. Bouwens (UCO/Lick & Leiden U.), and the HUDF09 Team

The first stars appeared ~100 million years after the big bang, and ever since then stars and star formation processes have lit up the cosmos. When the universe was about 3 billion years old, star formation activity peaked at rates about 10 times above current levels...

A photo of the PanSTARRS (Panoramic Survey Telescope & Rapid Response System) telescope in Hawaii. Astronomers have used a sky survey from this facility to identify a class of blue, hypervariable galaxies; the origin of the variability is uncertain but might in some cases be due to microlensing. Credit: PanSTARRS

Extreme variability in the intensity of the optical light of galaxies, by factors of 2 or more, is of great interest to astronomers. It can flag the presence of rare types of supernovae, for example, or spot sudden accretion activity around quiescent black holes or around the supermassive black hole at the galaxy’s nucleus. In recent years systematic searches for such variability have been made using instruments that can survey wide swaths of the sky...

Griffin and Dai developed the data collection methodology used to detect the gamma-ray emission from Arp 220. Credit: University of Oklahoma and NASA

A Uni of Oklahoma team has detected for the first time the most luminous gamma-ray emission from a galaxy -the merging galaxy Arp 220 is the nearest ultraluminous infrared galaxy to Earth, and it reveals the hidden extreme energetic processes in galaxies. The first gamma-ray detection of an ultraluminous infrafred galaxy occurs when the most energetic cosmic rays collide with the interstellar medium causing these galaxies to glow – expanding observations of these galaxies to the highest energy ranges...

Left: Chart of nuclides and important astrophysical reactions. Right: SOHO-EIT image from 14 September 1997 showing a huge eruptive prominence in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. The material in the eruptive prominence is at temperatures of 60,000 – 80,000 K, much cooler than the surrounding corona, which is typically at temperatures above 1 million K. Credit: Image courtesy of Texas A&M Cyclotron Institute and NASA

How old is the universe? What causes a star to catastrophically explode? Answering these and other questions about stellar evolutions requires knowing the rates of the reactions involved...