Latest Stellar evolution Stories
John P. Millis, PhD for redOrbit.com – Your Universe Online Astronomers have long been aware of supernovae – brilliant explosions ejecting massive amounts of gas and energy into the surrounding medium. But occasionally one of them is different, set apart, unlike anything we have seen before. Researchers with the Harvard-Smithsonian Center for Astrophysics (CfA) have announced in a new paper that one such event has been discovered. Supernovae are split into sub-types. While some...
Lee Rannals for redOrbit.com – Your Universe Online White dwarf supernovae that occurred millions of years ago have popped up in the Virgo Cluster galaxy and part of the sky labelled as "anonymous." Southern Methodist University (SMU) researchers say they've confirmed two bright stars that showed up in our skies in February and November are supernovae. Supernovae are the result of stars that have reached the end of their life, resulting in a large explosion that can consume anything...
The Royal Astronomical Society Continuing a tradition stretching back more than 25 centuries, astronomers have used the new 2.3-m 'Aristarchos' telescope, sited at Helmos Observatory (2340m high) in the Pelοponnese Mountains in Greece, to determine the distance to and history of an enigmatic stellar system, discovering it to likely be a binary star cocooned within an exotic nebula. The researchers, Panos Boumis of the National Observatory of Athens and John Meaburn of the University of...
Lee Rannals for redOrbit.com – Your Universe Online A rare explosion from a rotating star may have created the most recent black hole formed in the Milky Way galaxy. Astronomers using NASA's Chandra X-ray Observatory claim that matter was ejected at high speeds along the poles of a rotating star, creating a supernova remnant, W49B, which may contain a young black hole. "W49B is the first of its kind to be discovered in the galaxy," said Laura Lopez, who led the study at the...
Lee Rannals for redOrbit.com - Your Universe Online New observations have led to a better understanding of supernovae, which could one day lead to even better forecasts for the cosmic events. Type II supernovae form when a massive star collapses, sending off a giant explosion from the dying star. Having a better way to predict these events would allow astronomers to study them in their earliest stages. Astronomers wrote in the journal Nature this week that they have observed an...
April Flowers for redOrbit.com - Your Universe Online Astrophysicists have debated the outcome of two binary stars – stars that orbit each other – coming together in a "common envelope" for a long time. A new study from the University of Alberta has finally provided some answers. Theoretical astrophysicist Natalia Ivanova has revealed the workings of a celestial event that produces an explosion so powerful its luminosity approaches that of a supernova. “When this dramatic...
Lee Rannals for redOrbit.com - Your Universe Online A Rutgers University astronomer has created computer models and simulations that help to explain how galaxies formed and evolved. Astronomer Rachel Somerville, who works as a professor of astrophysics in the Department of Physics and Astronomy, School of Arts and Sciences, created these models to show how gases like hydrogen and helium coalesce into stars and galaxies and how exploding stars and black holes impact their galactic...
Lee Rannals for redOrbit.com - Your Universe Online According to a new study, black hole cosmic radiation blasted into the Earth back in the 8th century. Japanese astrophysicist Fusa Miyake discovered last year clues for the strange event located in the rings of ancient cedar trees that dated back to either 774 or 775 AD. Researchers teamed together to determine what had caused the surge in carbon-14 in the rings and found no evidence of a supernova, as they had expected. The...
April Flowers for redOrbit.com - Your Universe Online A multinational team of scientists has revealed new information about the explosive events known as novae. Novae are dramatic stellar explosions driven by nuclear processes that make previously unseen stars visible for a short time. The team of astrophysicists measured the nuclear structure of the radioactive neon produced through this process in unprecedented detail. The study, led by the University of York, UK, and Universitat...
April Flowers for redOrbit.com - Your Universe Online Have you ever wished for a time machine to be able to travel to the distant past? What about a "Wayback Television Set" that would allow you to watch an entire month of ancient prehistory in real time? Berkeley Lab’s David Rubin gave just such a scenario to attendees at the American Astronomical Society meeting this week when he unveiled the discovery of a striking astronomical object. Rubin announced a Type Ia supernova with a...
Latest Stellar evolution Reference Libraries
The prominent feature that allows for the existence of life on Earth is the Sun. Radiation from our closest star provides heat and energy to our planet, driving biological processes and providing the necessary conditions for liquid water to naturally exist. But our Sun is only but one star in this vast Universe. And as it turns out, most stars are quite different than the one that illuminates our day. For this reason, scientists have, for hundreds of years, attempted to study the other...
Hertzsprung-Russell Diagram -- In stellar astronomy, the Hertzsprung-Russell diagram (H-R diagram) shows the relation between the absolute magnitude and the spectral types of stars. It was invented around 1910 by Ejnar Hertzsprung and Henry Norris Russell. There are two equivalent forms. One is the observer's form which plots the color of the star on one axis and the absolute magnitude on the other axis. The theoretician's form plots the temperature of the star on one axis and the...
White Dwarf -- A white dwarf is a a star supported by electron degeneracy. A star like our Sun will become a white dwarf when it has exhausted its nuclear fuel. Near the end of its nuclear burning stage, such a star goes through a red giant phase and then expels most of its outer material (creating a planetary nebula) until only the hot (T > 100,000 K) core remains, which then settles down to become a young white dwarf. A typical white dwarf is half as massive as the Sun, yet only...
Supernova Remnant -- A supernova remnant (SNR) is made up of the materials left behind by the gigantic explosion of a star in a supernova. There are two possible routes to this end: either a massive star may cease to generate fusion energy in its core, and collapse inward under the force of its own gravity, or a white dwarf star may accumulate material from a companion star until it reaches a critical mass and undergoes a similar collapse. In either case, the resulting supernova...
Supernova -- A supernova is a star that increases its brightness drastically within a matter of days, making it appear as if a "new" star was born (hence "nova"). The "super" prefix distinguishes it from a mere nova, which also involves a star increasing in brightness, though to a lesser extent and through a much different mechanism. Astronomers have classified supernovae in several classes, according to the lines of different elements that appear in their spectra. The first...
