Neue ALMA-Beobachtungen erklären warum milchstaßenähnliche Galaxien im Universum so häufig vorkommen
Jahrzehntelang glaubten Wissenschaftler, dass die Verschmelzung von Galaxien normalerweise zur Entstehung von elliptischen Galaxien führt. Nun haben Forscher zum ersten Mal mit Hilfe von ALMA und einer Reihe weiterer Radioteleskope einen direkten Beweis dafür gefunden, dass kollidierende Galaxien stattdessen Scheibengalaxien hervorbringen können, und dass dieser Ausgang in der Tat recht häufig ist. Dieses überraschenden Ergebnis könnte erklären, warum es im Universum so viele Spiralgalaxien wie die Milchstraße gibt. (more…)
PASADENA, Calif. — The spectacular barred spiral galaxy NGC 6872 has ranked among the biggest stellar systems for decades. Now a team of astronomers from the United States, Chile and Brazil has crowned it the largest known spiral, based on archival data from NASA’s Galaxy Evolution Explorer (GALEX) mission, which has since been loaned to the California Institute of Technology in Pasadena.
Measuring tip-to-tip across its two outsized spiral arms, NGC 6872 spans more than 522,000 light-years, making it more than five times the size of our Milky Way galaxy. (more…)
SAN FRANCISCO — Scattered around the Milky Way are stars that resemble our own sun—but a new study is finding that any planets orbiting those stars may very well be hotter and more dynamic than Earth.
That’s because the interiors of any terrestrial planets in these systems are likely warmer than Earth—up to 25 percent warmer, which would make them more geologically active and more likely to retain enough liquid water to support life, at least in its microbial form.
The preliminary finding comes from geologists and astronomers at Ohio State University who have teamed up to search for alien life in a new way. (more…)
ANN ARBOR, Mich.— Astronomers have detected a mysterious ring of carbon monoxide gas around the young star V1052 Cen, which is about 700 light years away in the southern constellation Centaurus.
The ring is part of the star’s planet-forming disk, and it’s as far from V1052 Cen as Earth is from the sun. Discovered with the European Southern Observatory’s Very Large Telescope, its edges are uniquely crisp. (more…)
TORONTO, ON – Three astronomers at the University of Toronto have found the most numerous batch of young, supermassive stars yet observed in our galaxy: hundreds of thousands of stars, including several hundreds of the most massive kind –blue stars dozens of times heavier than our Sun. The light these newborn stars emit is so intense it has pushed out and heated the gas that gave them birth, carving out a glowing hollow shell about a hundred light-years across.
These findings will be published in the December 20 issue of Astrophysical Journal Letters. For the researchers, the next step is already clear: “By studying these supermassive stars and the shell surrounding them, we hope to learn more about how energy is transmitted in such extreme environments,” says Mubdi Rahman, a PhD candidate in the Department of Astronomy & Astrophysics at the University of Toronto, who led the work with his supervisors, Professors Dae-Sik Moon and Christopher Matzner. (more…)
ANN ARBOR, Mich.—The first close-up picture of a nascent super massive star and its surroundings has shown that the highest mass stars in the universe form just like their smaller counterparts. They are born from swirling disks of gas and dust, rather than from violent stellar collisions.
“How these high mass stars form has been a debate for 20 years,” said Stefan Kraus, a research fellow in the University of Michigan Department of Astronomy who is first author of a paper on the findings published July 15 in Nature.
