There are billions of stars and planets in the universe. A star is a glowing sphere of gas, while planets like Earth are made up of solids. The planets are formed in dust clouds that swirled around a newly formed star. Dust grains are composed of elements like carbon, silicon, oxygen, iron, and magnesium. But where does the cosmic dust come from? New research from the Niels Bohr Institute at the University of Copenhagen and Aarhus University shows that not only can grains of dust form in gigantic supernova explosions, they can also survive the subsequent shockwaves they are exposed to. The results are published in the prestigious scientific journal Nature. Read more…
A group of astronomers has been able to follow stardust being made in real time — during the aftermath of a supernova explosion. For the first time they show that these cosmic dust factories make their grains in a two-stage process, starting soon after the explosion, but continuing for years afterwards. The team used ESO’s Very Large Telescope (VLT) in northern Chile to analyze the light from the supernova SN 2010jl as it slowly faded. The new results are published online in the journal Nature on 9 July 2014.
The origin of cosmic dust in galaxies is still a mystery . Astronomers know that supernovae may be the primary source of dust, especially in the early universe, but it is still unclear how and where dust grains condense and grow. It is also unclear how they avoid destruction in the harsh environment of a star-forming galaxy. But now, observations using ESO’s VLT at the Paranal Observatory in northern Chile are lifting the veil for the first time. Read more…
An observatory run by the University of Utah found a “hotspot” beneath the Big Dipper emitting a disproportionate number of the highest-energy cosmic rays. The discovery moves physics another step toward identifying the mysterious sources of the most energetic particles in the universe.
Astrophysical Journal Letters
“This puts us closer to finding out the sources — but no cigar yet,” says University of Utah physicist Gordon Thomson, spokesman and co-principal investigator for the $25 million Telescope Array cosmic ray observatory west of Delta, Utah. It is the Northern Hemisphere’s largest cosmic ray detector.
“All we see is a blob in the sky, and inside this blob there is all sorts of stuff — various types of objects — that could be the source” of the powerful cosmic rays, he adds. “Now we know where to look.” Read more…
Mysteries about controversial signals coming from a dwarf star considered to be a prime target in the search for extraterrestrial life now have been solved in research led by scientists at Penn State University. The scientists have proven, for the first time, that some of the signals, which were suspected to be coming from two planets orbiting the star at a distance where liquid water could potentially exist, actually are coming from events inside the star itself, not from so-called “Goldilocks planets” where conditions are just right for supporting life.
The study will be published by the journal Science in its online Science Express issue [http://www.sciencemag.org/content/early/recent] on July 3, 2014, and in a future print edition of the journal [http://www.sciencemag.org].
“This result is exciting because it explains, for the first time, all the previous and somewhat conflicting observations of the intriguing dwarf star Gliese 581, a faint star with less mass than our Sun that is just 20 light-years from Earth,” said lead author Paul Robertson, a postdoctoral fellow at Penn State who is affiliated with Penn State’s Center for Exoplanets and Habitable Worlds. As a result of this research, the planets now confirmed to be orbiting this dwarf star total exactly three. Read more…
Discovery Expands Search for Earth-Like Planets: Newly Spotted Frozen World orbits in a Binary Star System
A newly discovered planet in a binary star system located 3,000 light-years from Earth is expanding astronomers’ notions of where Earth-like — and even potentially habitable — planets can form, and how to find them.
At twice the mass of Earth, the planet orbits one of the stars in the binary system at almost exactly the same distance from which Earth orbits the Sun. However, because the planet’s host star is much dimmer than the Sun, the planet is much colder than the Earth — a little colder, in fact, than Jupiter’s icy moon Europa.
Four international research teams, led by professor Andrew Gould of The Ohio State University, published their discovery in the July 4 issue of the journal Science [http://www.sciencemag.org].
The study provides the first evidence that terrestrial planets can form in orbits similar to Earth’s, even in a binary star system where the stars are not very far apart. Although this planet itself is too cold to be habitable, the same planet orbiting a Sun-like star in such a binary system would be in the so-called “habitable zone” — the region where conditions might be right for life.
“This greatly expands the potential locations to discover habitable planets in the future,” said Scott Gaudi, professor of astronomy at Ohio State. “Half the stars in the galaxy are in binary systems. We had no idea if Earth-like planets in Earth-like orbits could even form in these systems. ” Read more…