One early result of the ongoing Dark Energy Survey is the previously untold story revealed by old, giant RR Lyrae pulsating stars, which tell scientists about the region of space beyond the edge of our Milky Way. In this area nearly devoid of stars–the motion of the RR Lyrae stars hints at the presence of an enormous halo of invisible dark matter, which may provide clues to how our galaxy evolved over the last 12 billion years.
In the Milky Way Galaxy, about three-fourths of the stars are M dwarfs, and the proportion is even higher in elliptical galaxies. But there’s a deadly catch. New research indicates orbiting close to these low-mass stars, prime targets for astronomers in the search for extraterrestrial life, may have lost their window of opportunity at hosting life because of intense heat during their formative years. M dwarfs, also known as red dwarfs, are the smallest type of hydrogen-burning star and are the most common stars and the coolest main-sequence stars in the universe.
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The story: In April of 2019, Space Telescope Science Institute astronomer Marc Postman said that when he first first saw the Hubble image of the monster elliptical galaxy galaxy in the Abell 2261 galaxy cluster with a core bigger and brighter than any seen before, he knew immediately that something was odd, that its central core embraced a mystery never before seen. Spanning a little over one million light-years, the galaxy is about ten times the diameter of our own, and itself massive, Milky Way galaxy.
When stars thirty times bigger than our sun explode, they produce a type of young neutron star called a magnetar –the most magnetic objects in the universe, with gravity a billion times Earth’s and a magnetic field one-thousand-trillion times stronger than our Sun’s. A blast from magnetar could blow our atmosphere into space, leaving Earth a lifeless rock. Astronomer Phil Plait describes death by a magnetar should you venture too close as “the tides tearing you to pieces, the fierce heat vaporizing you, the magnetic field tearing your atoms apart, or the intense gravity crushing you into a thin paste an atom high.”
