430 The Magnificent Seven

The Magnificent Seven is a group of nearby (within 1,000 light-years, less than a few hundred parsecs) middle-aged (several hundred thousand years old) isolated neutron stars cooling by emitting x rays. The Magnificent Seven represent a large class of young neutron stars with many properties different from normal radio pulsars. There are other types of […]

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432 Strongest Consistent X-Ray Source

Next to the Sun, the strongest consistent x-ray source (and also the first extrasolar x-ray source discovered) is Scorpius X-1 which lies 9,000 light-years away in the direction of the constellation Scorpius. Detected in 1962, its x-radiation is not only strong but, like other x-ray sources, quite variable as well. Its variability exhibits two states, […]

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442 Winds from Massive Stars

The winds from massive stars are at least a hundred million times stronger than the solar wind emitted by our Sun. Hubble peers into a celestial geodeimage (based on AJ, 124, 3325), see also the HST-ESA (ESA) release, Spaceflight, Space.com, Innovations Report, SpaceRef, EurekAlert. These data were Astronomy Picture of the day on August 19 […]

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451 Nearest Brown Dwarf

The nearest brown dwarf is actually two of them in the binary system Luhman 16, which lies 6.59 light-years away in the southern constellation Vela. Astronomers have used the NASA/ESA Hubble Space Telescope to track the two components of Luhman 16AB, the third closest system to the Solar System. Luhman 16AB, also known as WISE […]

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453 Thuban Was Once the North Star

Some 5,000 years ago, Thuban (Alpha Draconis)—apparent magnitude 3.7—was the North Star. Thuban is not a particularly bright star, but it holds a special place in the hearts of stargazers. That’s because Thuban was the Pole Star some 5,000 years ago, when the Egyptians were building the pyramids. Nowadays, Thuban is a relatively inconspicuous star […]

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454 Stars Don’t Twinkle

Stars don’t twinkle until their light passes through Earth’s atmosphere. The twinkling of stars in our night sky is down to the Earth’s atmosphere. As light from the stars travels towards Earth it can easily move in a straight line, but once it starts travelling through the Earth’s atmosphere it gets bounced around in different […]

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