Stories tagged stars
Hohenzollern Castle and the Big Dipper above the clouds
Courtesy Allthesky.comCheck out The Sky in Motion, a nifty 4+ minute time lapse video created by Till Credner of the Max Planck Institute of Solar System Research. Then check out his Allthesky.com homepage. It contains links to loads of digital images of space and atmospheric phenomenon such as eclipses, lightning, comets, auroras, etc. The site originates in Germany and I think you'll agree it contains many remarkable images.
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Black hole in action: Artist's rendition of a distant super-massive black hole warping space while busy eating up stellar material.
Courtesy NASA/JPL-CaltechScientists now have a better idea why stars can still form out of giant molecular clouds being ripped apart by the gravitational pull of a nearby massive black hole.
The observed existence of huge stars in eccentric orbits around the super-massive black hole believed to be located at the center of our Milky Way galaxy has puzzled scientists. How can stars form in such extreme environments? Gravitational forces would be tremendous near the black hole, tearing apart everything in the immediate region.
The computer simulations, done by researchers from St Andrews University in the UK, show how a molecular cloud – a normal stellar nursery – is torn apart by the black hole’s immense gravitation pull. Although the powerful gravity-well eats a huge portion of the gas cloud, the remaining gases are still able to accrete more material and coalesce into stars.
This is possible because as a molecular cloud enters the black hole’s gravitational field it begins to form into a spiraling elliptical disk. The disk’s matter nearest the black hole is sucked into the gravitational vortex, while energy is transferred to the remaining outer material. This transferred energy allows the remnants to retain the eccentric orbital path as they form into huge stars many times the mass of the Sun.
"These simulations show that young stars can form in the neighborhood of super-massive black holes as long as there is a reasonable supply of massive clouds of gas from further out in the galaxy," said co-author Ian Bonnell. The study’s results appear in the current issue of Science.
The stars live fairly short lives - perhaps only about 10 million years. But their existence could help explain some of the mysteries surrounding black holes in galaxies.
LINKS
Story on BBC website
Science magazine abstract
More on super-massive black holes
Sky spy: This new device -- the SkyScout -- uses GPS to take all the guess work out of astronomy. Point the videocamera-sized unit at light in the heavens and it wiil identify what it is. (Photo from Celestron)Looking for that special gift for the astronomer who has everything?
Have you heard about SkyScout? It’s a nifty new tool that costs about $400 but makes identifying things you spot in the heavens a lot easier.
About the size of video camera, the unit made by Celestron can help you identify a particular light you’re seeing in the sky. Or, you can punch in key data and have scan the skies so you can find a particular star or planet.
How does it work?
When you turn on the unit, SkyScout’s global positioning systems first work to identify where you’re at and what day and time it is. By placing the object you want to identify at the center of its concentric circle viewing scope, it then reads landmark stars and objects in the sky to zero in on the item you’re interested in. An audio option can be turned on so that SkyScout will verbally tell you what you’re looking at.
On the flip side, if you want to find Venus, let’s say, you’d simply click on that celestial body on the SkyScout’s menu. Arrows in the viewfinder will guide to move SkyScout in the right directions to that you ultimately get it in your sights. SkyScout has a database of 6,000 heavenly bodies to search out that way.
A Star-Tribune story that ran over the weekend about the unit said that one local astronomy store – Radio City in Moundsview – can’t keep the units on the shelf. And a competitor product, MySky, has just entered the market.
What do you think of this new application of GPS? Have you tried a SkyScout or MySky? Share your thoughts here with other Science Buzz readers.
SN 2006gy Explodes into Space: Image courtesy Wikimedia Commons.Scientists have observed what is thought to be the most powerful supernova explosion ever recorded.
"Of all exploding stars ever observed, this was the king," said Alex Filippenko, one of the astronomers observing the event.
The object, dubbed SN 2006gy, is thought to have been a star at least 150 times larger than our own sun. It was first discovered last autumn, and its subsequent death throes were so explosive, astronomers think the star may have been obliterated, blasting all its material (metals and heavier elements) into the surrounding region of space. Animation of a star going supernova.
But have no fear, it should have no effect on any of us here on Earth. Astronomers estimate the star was 240 million light-years away from our solar system.
However, a star in our own galaxy named Eta Carinae, appears to be expelling large amounts of material just like SN 2006gy did before it went supernova. It could mean Eta Carinae is facing a similar explosive fate. And if that happens, its demise would not go unnoticed here on Earth, because Eta Carinae is only 7500 light-years away.
"We don't know for sure if Eta Carinae will explode soon, but we had better keep a close eye on it just in case," said Mario Livio, of the Space Telescope Science Institute in Baltimore. The last supernova observed in the Milky Way took place more than 400 years ago.
"Eta Carinae's explosion could be the best star-show in the history of modern civilization," Livio said.
"It would be so bright that you would see it during the day, and you could even read a book by its light at night", added Dave Pooley, at the University of California at Berkley.
Despite the celestial light show, and its relative closeness, if Eta Carinae did go supernova, it would still be a safe distance away from Earth.
LINKS AND INFO
BBC Story
More On SN 2006gy
Physorg.com
CHANDRA Supernova Site
You can interactively zoom into and pan around these high-resolution images from the Spitzer Space Telescope. JavaScript and a current installation of Flash are required.
I love Earth & Sky radio's skywatching center. It always features tonight's sky chart and weather, plus skywatching tips and any news. Find out when the moon will rise, what phase of the moon we're in, and where visible planets will be in the sky and when you should look. Plus, it's packed with links to other resources, like interviews with scientists and web planetariums. And you can blog! Check it out...
How does one explain the enormous magnetic field strengths of the
so-called 'magnetic stars'? This question concerning magnetic fields in
the cosmos, first posed half a century ago, has now been answered. Learn more.
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