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Star Betelgeuse - A red supergiant in the constellation Orion

One fascinating star is Betelgeuse, a red supergiant located in the constellation Orion. Here are some intriguing facts about it: 1. Size and Volume: Betelgeuse is immense—if placed at the center of our solar system, it would extend past the orbit of Mars. 2. Variability: It is a pulsating variable star, meaning its brightness changes over time; it has been observed to vary in brightness over several months. 3. Life Cycle: Betelgeuse is nearing the end of its life cycle and is expected to explode as a supernova within the next million years, a relatively short time in astrophysical terms. 4. Distance: It is located approximately 640 light-years away from Earth. 5. Cultural Significance: Betelgeuse has been significant in many cultures and is commonly referred to as the “Shoulder of the Hunter” in the constellation Orion. 6. Color Indicator: Its reddish hue signifies a cooler surface temperature compared to other stars, which gives it a distinctive appearance. Betelgeuse con...
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What ionized the universe?

The sparsely distributed hot gas that exists in the space between galaxies, the intergalactic medium, is ionized. The question is, how? Astronomers know that once the early universe expanded and cooled enough, hydrogen (its main constituent) recombined into neutral atoms. Then, once newly formed massive stars began to shine in the so-called "era of reionization," their extreme ultraviolet radiation presumably ionized the gas in processes that continue today. One of the key steps, however, is not well understood, namely the extent to which the stellar ionizing radiation escapes from the galaxies into the IGM. Only if the fraction escaping was high enough during the era of reionization could starlight have done the job, otherwise some other significant source of ionizing radiation is required. That might imply the existence of an important population of more exotic objects like faint quasars, X-ray binary stars, or perhaps even decaying/annihilating particles.

from Astronomy News - Space News, Exploration News, Earth Science News, Earth Science https://ift.tt/2CwQs9V
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