How Big is the Biggest Star in the Universe?

A comparison between the Sun and a hypermassive star. Credit: NASA

So how big is it? According to Fraser at the Universe Today, the largest known star is VY Canis Majoris. This is a massive star, otherwise known as a red hypergiant star and this one sits in the constellation Canis Major, about 5000 light years from Earth. Apparently it is more than 2100 times the size of our Sun, a monster! This star is so big that light takes more than eight hours to cross its circumference. In fact, this star, if placed in the centre of the Solar System, it would reach as far as the orbit of Saturn.

Although VY Canis Majoris is big, it isn’t as big as the biggest star could be. If it was cooler, a similar star could reach over 2600 times the size of our Sun…

What’s Going on with These Sunspots? Are they from Solar Cycle 23 or 24?

Magnetic view of the new sunspots appearing at the Suns equator (credit: SOHO)

On posting the story “The Sun Bursts to Life: Sunspots, Flares and CMEs” on the Universe Today, something was strange about my source material. Although the Sun had started Solar Cycle 24 back in January of this year, the new sunspots recently observed were the “leftovers” from the previous cycle and not new ones from this cycle. Something is strange. Surely one cycle ends and another begins? Think again…
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When a Moon Makes a World of a Difference

Io and Jupiter - a dynamic pair…

The Earth’s Van Allen belts are the location for some of the most fearsome particles in space. Highly energetic particles from the Sun get trapped in the layers of the magnetosphere, setting them up for an injection of waves causing acceleration and heating. This naturally causes concern for astronauts and spacecraft passing out of the atmosphere and into this bubble of radiation only 200 miles above the surface. But spare a thought for any spacecraft passing through Jupiter’s magnetic field. The energetic particles there are far more powerful, plus one of the Jovian moons has a huge part to play, generating the plasma waves accelerating the particles even more…
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Supermassive Black Holes Can’t Swallow Dark Matter

A modelled accretion disk around a black hole. Image credit: Michael Owen, John Blondin (North Carolina State Univ.). Source: http://apod.nasa.gov/apod/ap050312.html

Apparently, black holes and dark matter don’t play well together. Broadly speaking, black holes can be considered to be a significant portion of the “missing mass” in the universe, but dark matter is distinguished as “non-baryonic matter”. It seems that this mysterious non-baryonic matter is being used to explain a huge number of unexplained cosmic mysteries, but in the case of supermassive black holes, dark matter plays a very small role insofar as being used as black hole food…
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Daily Roundup: The Solar Wind Strips Mars Bare. Look Out Venus, You’re Next!

Venus atmosphere is being eroded by the Sun. Image credit: ESA

We are very lucky here on Earth, we have a powerful magnetic field, known as the magnetosphere surrounding us and our atmosphere, protecting us from the worst that the Sun can throw at us. Other planets in our Solar System ain’t so lucky. Poor old Mars has been damaged beyond repair by the constant erosion by the solar wind, dragging most of its atmosphere into space. Now, Earth’s planetary sister, Venus, is showing signs of atmospheric leakage… where will it end?
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Question of the Day: Were Moons Nix and Hydra Adopted by Pluto and Charon?

The Pluto-Charon system. Image credit: NASA/HST

OK, here are two questions on everybody’s lips:
1) Could we be wiped out by an asteroid in the near future?
2) Are Pluto and Charon’s kids adopted?

Well, #1 has probably been asked a few times (most likely during crappy movies like Deep Impact), but #2? I’m hoping this is the first time it’s ever been asked… and it’s a very important question… well, kinda.
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Snippet: Space Debris is Becoming a Serious Problem, but Google Earth is Watching

Space junk as plotted in the Google Earth software.

Every time a rocket launches, a spaceship orbits, an astronaut drops some trash or the US blows up a satellite, debris is created. Space debris (a.k.a. space junk) is a nasty side-effect of our push into space, but it isn’t a recent phenomenon. Even the early Gemini missions in the sixties did it, as does the ultra-efficient International Space Station – bits of spacesuits, cameras, nuts, bolts and tools are accidentally (and deliberately) dropped into the vacuum. But it’s only a bit of litter right? Wrong. That’s a hyper-velocity rifle shot, and it’s coming to a spaceship very soon, if we don’t take action now…
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Snippet: Where Science and Art Meet – The Internet “Universe” Frozen in Time

San Diego Supercomputer Center image of the Internet Universe frozen in time. Image credit: UCSD. Souce:http://www.physorg.com/news122832578.html

This striking image has been created by tracking the round-trip times of data packets sent from a web site in Virginia to thousands of nodes around the World Wide Web. Using a new technique, this visualization method (3D “hyperbolic geometry”) allows the viewer to analyse large amounts of data mapped around a sphere. Not only does it give an insight to where data travels around the Internet – like an electronic dye highlighting the route packets of data take – it has also become a work of art…
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Snippet: Can Pieces of Mercury be Found on Earth?

A meteorite on the surface of Mars. Image credit: NASA/JPL

This is an interesting thought. We know that rocks from space can fall through the atmosphere and hit the ground as meteorites. But where do these rocks come from? Some come from old remnants of the early solar system, floating through space until they are captured by the Earth’s gravitational pull. Other meteorites come from other planets, ejected pieces of the planet crust (caused itself by a meteorite impact), escaping from the planets gravity by achieving “escape velocity”. We have found samples known to come from the Moon and Mars, but what about the other planets? Venus’ atmosphere is too thick to allow pieces of its surface to fly into space, but what about the first planet from the Sun, Mercury? Can bits of Mercury travel through space and land on Earth?
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Snippet: Will the Earth be Safe From Solar Expansion? The Outlook Isn’t Great…

As the Sun runs out of fuel, it will swell… but will it swell enough to swallow the Earth? Image credit: Mark Garlick/HELAS. Source: http://www.sciam.com/article.cfm?id=exoplanet-red-giant-space-astronomy-stars

In 7 billion years time, the Sun will run out of fuel. As it dies, it will swell so big that many predict that it will reach as far as Earth’s orbit. Naturally, the likelihood of the Earth still harbouring life may be debatable (after all 7 billion years is a long, long time), but should the human race still be around, and evolved into something totally unrecognizable, what will we see?
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