The sublime beauty and the danger of physics is that sometimes things exist that we can never see. Which led scientists to ask: Was an unknown object, perhaps a cosmic string, weird one-dimensional defects in space-time that should be out there, somewhere, detected at the Milky Way’s galactic center in 2016? If yes, it could have profound implications for understanding gravity, space-time and the universe itself.
“These objects look like gas and behave like stars,” said co-author Andrea Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the UCLA Galactic Center Group about a new class of bizarre objects with orbits ranging from about 100 to 1,000 years at the center of our galaxy, not far from the supermassive black hole called Sagittarius A* that look compact most of the time and stretch out when their orbits bring them closest to the black hole.
Gravitational waves, an oscillatory space warp –an oscillating stretch and squeeze of space, according to Stephen Hawking, have reveled a neutron star binary, called GW190425, more massive than any ever seen in the Milky Way has mystified scientists—until now. A team of astrophysicists from Australia’s ARC Center of Excellence for Gravitational Wave Discovery (OzGrav) think they might have the answer.
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“The evolution of elliptical galaxies is totally different than the Milky Way,” says astrophysicist Daniel Whitmire. “These galaxies went through an early phase in which there is so much radiation that it would just completely have nuked any habitable planets in the galaxy and subsequently the star formation rate, and thus any new planets, went to essentially zero. There are no new stars forming and all the old stars have been irradiated and sterilized.”
NASA’s WFIRST’s infrared telescope will explore uncharted regions of the galaxy for exoplanets due to the different goals of previous missions. Kepler, for example, searched a modest-sized region of about 100 square degrees with 100,000 stars at typical distances of around a thousand light-years. TESS scans the entire sky and tracks 200,000 stars; however their typical distances are around 100 light-years. WFIRST will search roughly 3 square degrees, but will follow 200 million stars at distances of around 10,000 light-years.
