You might think that astronomers could easily tell the difference between a black hole and a white dwarf — but nature can be deceptive. Astronomers from the Sloan Digital Sky Survey (SDSS) have just announced the results of a new study that reveals the true origin of puzzling light from nearby galaxies.
How many stars like our Sun host planets like our Earth? NASA’s Kepler Space Telescope continuously monitored more than 150,000 stars beyond our solar system, and to date has offered scientists an assortment of more than 4,000 candidate planets for further study — the 1,000th of which was recently verified.
Astronomers can’t find any sign of the black hole at the centre of the quasar SDSS J1011+5442, and they couldn’t be happier. The black hole is still there, of course, but over the past ten years, it appears to have swallowed all the gas in its vicinity. With the gas consumed, researchers were unable to detect the spectroscopic signature of the quasar, which now appears as an otherwise normal galaxy.
Astronomers have created the first large-scale map that shows stellar ages in the Milky Way by determining the ages of nearly 100,000 red giant stars, at distances of up to 50,000 light-years from the galactic centre. Notably, the map confirms that our home galaxy has grown inside out: in the present epoch, most old stars can be found in the middle, more recently formed ones in the outskirts.
Researchers from Australia and the USA have discovered a distant, ancient cloud of gas that may contain the signature of the very first stars that formed in the universe. The gas cloud is many billions of light-years away from Earth, and is observed as it was just 1.8 billion years after the Big Bang.
The early universe was a chaotic mess of gas and matter that only began to coalesce into distinct galaxies hundreds of millions of years after the Big Bang. It would take several billion more years for such galaxies to assemble into massive galaxy clusters — or so scientists had thought. Now astronomers have detected a massive, sprawling, churning galaxy cluster that formed only 3.8 billion years after the Big Bang, some 10 billion light years from Earth.
Ripples in gas at the outer disc of our galaxy have puzzled astronomers since they were first revealed by radio observations a decade ago. Now, astronomers believe they have found the culprit — a dwarf galaxy, containing dark, unseen material, which skimmed the outskirts of the Milky Way a few hundred million years ago. This method to characterise dark matter marks first real application of galactoseismology.
Located about 7,500 light-years away in the southern constellation of Carina, Eta Carinae outshines our Sun by 5 million times. The binary system consists of two massive stars in a tight 5.5-year orbit, shrouded in an expanding veil of gas and dust from an enormous eruption seen in the 1840s. Now a study using archival data from NASA’s Spitzer and Hubble space telescopes has found five similar objects in other galaxies for the first time.
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