supernovae tagged posts

Unlike most stellar explosions that fade away, supernova SN 2012au continues to shine today thanks to a powerful new pulsar.
Credit: NASA, ESA, and J. DePasquale (STScI)

The explosions of stars, known as supernovae, can be so bright they outshine their host galaxies. They take months or years to fade away, and sometimes, the gaseous remains of the explosion slam into hydrogen-rich gas and temporarily get bright again – but could they remain luminous without any outside interference?

That’s what Dan Milisavljevic, an assistant professor of physics and astronomy at Purdue University, believes he saw six years after “SN 2012au” exploded...

This is an artist’s concept of the metric expansion of space, where space (including hypothetical non-observable portions of the universe) is represented at each time by the circular sections. Note on the left the dramatic expansion (not to scale) occurring in the inflationary epoch, and at the center the expansion acceleration. The scheme is decorated with WMAP images on the left and with the representation of stars at the appropriate level of development. Credit: NASA

Scientists have created computer simulations of events soon after the Big Bang to better understand how stars today are being formed. Researchers have formed the clearest picture yet of massive explosions that controlled the creation of galaxies, including our own, and continue to influence star formation today...

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...