Combining images taken with the NASA/ESA Hubble Space Telescope over more than 20 years, a team of researchers has discovered that Eta Carinae, a very massive star system that has puzzled astronomers since it erupted in a supernova-like event in the mid-19th century, has a past that’s much more violent than they thought.
Some 3.9 billion years ago in the heart of a distant galaxy, the intense tidal pull of a monster black hole shredded a star that passed too close. After X-rays produced in this event first reached Earth on 28 March 2011, scientists concluded that the outburst, now known as Swift J1644+57, also represented the sudden flare-up of a previously inactive black hole.
Using data gathered by NASA’s New Horizons spacecraft on its Pluto flyby in July 2015, the dwarf planet has some characteristics less like that of a comet and more like much larger planets, according to the first analysis of Pluto’s unique interaction with the solar wind — the charged particles that spew off from the Sun into the solar system at a supersonic 1 million mph.
Astronomers have used interferometry to create a time-lapse of the nearby star zeta Andromedae over one of its 18-day rotations that show starspots — sunspots outside our solar system. The pattern of spots on the star is very different from their typical arrangement on our Sun, challenging current theories of how stars’ magnetic fields influence their evolution.
Earlier this year scientists presented evidence for Planet Nine, a Neptune-mass planet in an elliptical orbit 10 times farther from our Sun than Pluto. New research examining theories how this planet could end up in such a distant orbit finds that most scenarios have low probabilities. Therefore, the presence of Planet Nine remains a bit of a mystery.
Some 300 so-called hot Jupiters have been identified over the past two decades, but how did these large, hot planets ever get so close to their suns? Now scientists have made a startling discovery: One of these mysterious hot Jupiter systems has not one, but two close-in planetary companions, leading to new clues about planet formation and migration.
Astronomers using NASA’s Chandra X-ray Observatory and the 6.5-metre Clay Telescope in Chile have identified the smallest supermassive black hole ever detected in the centre of a galaxy. This oxymoronic object could provide clues to how larger black holes formed along with their host galaxies 13 billion years or more in the past.
Astronomers have uncovered a unique process for how the universe’s largest elliptical galaxies continue making stars long after their peak years of star birth. NASA’s Hubble Space Telescope revealed brilliant knots and chains of hot, blue stars forming along the jets of active black holes found in the centres of giant elliptical galaxies.
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