Stories tagged stars

Jan
03
2013

GLOBE at Night
GLOBE at NightCourtesy GLOBE at Night
(This post is a copy and paste of an email I received for this interesting citizen scientist activity...)

What would it be like without stars at night? What is it we lose? Starry night skies have given us poetry, art, music and the wonder to explore. A bright night sky (aka light pollution) affects energy consumption, health and wildlife too. Spend a few minutes to help scientists by measuring the brightness of your night sky. Join the GLOBE at Night citizen-science campaign. There are 5 GLOBE at Night campaigns in 2013: January 3 - 12, January 31 - February 9, March 3 - 12, March 31 - April 9, and April 29 - May 8. Make a difference and join the GLOBE at Night campaign.

GLOBE at Night is a worldwide, hands-on science and education program to encourage citizen-scientists worldwide to record the brightness of their night sky. During five select sets of dates in 2013, children and adults match the appearance of a constellation (Orion or Leo in the northern hemisphere, and Orion and Crux in the southern hemisphere) with seven star charts of progressively fainter stars. Participants then submit their choice of star chart with their date, time and location. This can be done by computer (after the measurement) or by smart phone or pad (during the measurement). From these data an interactive map of all worldwide observations is created. Over the past 7 years of 10-day campaigns, people in 115 countries have contributed over 83,000 measurements, making GLOBE at Night the most successful, light pollution citizen-science campaign to date. The GLOBE at Night website is easy to use, comprehensive, and holds an abundance of background information. Through GLOBE at Night, students, teachers, parents and community members are amassing a data set from which they can explore the nature of light pollution locally and across the globe.

Listen to a fun skit on GLOBE at Night in a 7-minute audio podcast here.

Twinkle, twinkle little star, how many of you out there are: Start counting right now and you might have a chance to figure out how many stars are up in the heavens.
Twinkle, twinkle little star, how many of you out there are: Start counting right now and you might have a chance to figure out how many stars are up in the heavens.Courtesy European Space Agency
Here in Minnesota we live the land of political recounts. But in the world of astronomy, a recount on the density of the heavens is leading to the conclusion there might be three times as many stars in the sky than we have thought in the past. Just how many stars are there? You'll have to click this link to get that astronomically large number.

It's Friday, so it's time for another Science Friday video. Science Friday
Science Friday
Courtesy Science Friday
NASA's Solar Dynamics Observatory (SDO), launched in February, has started to send back data. The instruments are giving solar scientists an unprecedented look at the sun, says Dean Pesnell, SDO project scientist. The hope is to better understand how solar activity--solar flares, coronal mass ejections, coronal holes--is linked to the sun's magnetic field.

VY Canis Majoris v. our Sun: No contest.
VY Canis Majoris v. our Sun: No contest.Courtesy Public domain
If you’re like me, you’re fretting about what to buy your significant other this coming holiday season. Let it go. We have bigger problems. There’s a humongous star in the constellation Canis Major that’s in its final death throes and could go supernova at any time. VY Canis Majoris, as it is referenced, is the largest star known to science, and is so huge, if it were placed in the center of our Solar System, it would encompass all the space between our Sun and the orbit of the planet Saturn (see diagram). But don’t worry, the unstable red hypergiant is nearly 5000 light-years away, and is being monitored closely (in far-infrared and submillimeter portions of the light spectrum) by the European Space Agency's new space telescope Herschel. Read more here about what's actually going on.

More about the Herschel space observatory

Ever wondered if black holes really do exist? Most of us, at one time or another, have learned about what I would call the creepy part of outerspace: black holes. The idea of an object with such a strong gravitational force that even light cannot escape it's pull, is absolutely mind-boggling to me. Despite having learned about the concept in school, black holes have remained such a mystery that it's hard for me to really conceptualize their existence. However, today there is even more concrete evidence of a supermassive black hole in the center of the Milky Way galaxy! Take a look at this website for more information on this story.

Aug
25
2008

Black hole in action: Artist's rendition of a distant super-massive black hole warping space while busy eating up stellar material.
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-Caltech
Scientists 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

Aug
07
2007

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)
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.

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...