Researchers have gotten the closest look yet at the supermassive black hole that is believed to lurk in the center of the Milky Way, using radio telescopes to peer through the cosmic dust. Lead astronomer Sheperd Doeleman says: “One of the problems with looking at this particular source is that we have to look through our galaxy. It’s a blessing that it’s this close, but it’s a curse because it’s obscured by gas and dust” [SPACE.com].
Black holes can’t be directly observed, because their gravitational pull is so strong that nothing, not even visible light, can escape. To study our local gravitational monster, researchers homed in on Sagittarius A*, the bright radio-emitting body thought to mark the position of the black hole. Because Sagittarius A* is likely fueled by the black hole’s activity, a better look at the radio-emitting body can provide more details about the black hole [Science News].
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Astronomers have discovered that a massive star known as the Peony Nebula star ranks as the second-brightest in our Milky Way galaxy. The astronomers estimate that the star shines 3.2 million times as brightly as our sun, which is enough to get it a galactic silver medal; the brightest star ever detected is Eta Carinae, which is 4.7 million times brighter than our own little star.
The Peony nebula star… doesn’t look all that bright to the naked eye. Sirius is still the undisputed local champion, based on what we can see in the night sky. But a big factor behind Sirius’ apparent brightness is its relative proximity to Earth – a mere 8.7 light-years, or roughly 50 trillion miles [MSNBC]. In contrast, the Peony Nebula star lies about 26,000 light-years away, in the dusty heart of the Milky Way. In their upcoming report in the journal Astronomy & Astrophysics, researchers say the Spitzer telescope could reveal many other super-bright stars in the same region.
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It’s like an out-of-body experience, but on a galactic scale.
Astronomers have put together the best image yet of the Milky Way, the spiral galaxy that is home to the Earth, and more than 200 billion other stars. To map our galaxy from within, they used infrared cameras on NASA‘s Spitzer Space Telescope, which allowed them to see through cosmic clouds of dust and gas.
The resulting data painted a radically different picture of our galaxy, and revealed that only two great arms of stars spiral out from the center of the Milky Way, not four as previously thought.
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