Posted on by Nancy Atkinson

The Sun Blasts Out an X1-Class Solar Flare

An active region on the Sun, AR1515, has been putting on quite a show over the last 8 days, sending out all sorts of solar flares. Scientists were sure the huge sunspot was building up to produce an X-class explosion, and they were right. At 23:08 UT on July 6, 2012 it unleashed an X1-class solar flare. The explosion hurled a coronal mass ejection into space, and scientists say the cloud appears to be heading south and away from Earth; however, there is the possibility of a glancing blow to our planet on July 8th or 9th. There could be some auroral activity today, July 7, from a previous batch of CME’s hurled from the same active region.

According to the Solar Dynamics Observatory team, the movie above shows the X1 flare in various different wavelengths, which show different layers and temperatures. Each segment is about 30 minutes in real-time.

Below is another video from July 5-6, where AR1515 pulsed with with C- and M-class solar flares, about 14 flares in all:

Here’s an image of the action from SDO, with lots of activity going on:

“X1-class solar flare on the right, new active region on the left. Will the action continue?” asked Camilla_SDO, the mascot for the Solar Dynamics Observatory, via Twitter.

So, what’s the difference in the classes of solar flares and how could they affect us on Earth?

Flares happen when the powerful magnetic fields in and around the Sun reconnect. They’re usually associated with active regions, which we call sunspots, where the magnetic fields are strongest.

Flares are classified according to their strength. The smallest ones are B-class, followed by C, M and X, the largest. Similar to the Richter scale for earthquakes, each letter represents a ten-fold increase in energy output. So an X is 10 times an M and 100 times a C. Within each letter class, there is a finer scale from 1 to 9. Although X is the last letter, there are flares more than 10 times the power of an X1, so X-class flares can go higher than 9.

C-class flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts. The most powerful flare on record was in 2003, during the last solar maximum. It was so powerful that it overloaded the sensors measuring it. They cut-out at X28. A powerful X-class flare like that can create long lasting radiation storms, which can harm satellites and even give airline passengers, flying near the poles, small radiation doses. X flares also have the potential to create global transmission problems and world-wide blackouts.

That’s why we keep an eye on all this activity.

Sources: SDO, Spaceweather.com

Posted on by Nancy Atkinson

All 135 Space Shuttle Launches at Once

https://vimeo.com/27505192

We’re not sure how we missed this when it came out last year, but this incredible video shows all 135 launches of the space shuttle program at once. Creator McLean Fahnestock calls it “The Grand Finale” and rightly so. A great display of “fireworks” and a wonderful homage to the legacy of the space shuttles.

The one launch failure, Challenger on STS-51-L does stand out in this video and the words “obviously a major malfunction” will always linger. But the drive to keep striving for the heavens will always be there.

Posted on by Jason Major

The Last Outbursts of a Dying Star

As stars approach the inevitable ends of their lives they run out of stellar fuel and begin to lose a gravitational grip on their outermost layers, which can get periodically blown far out into space in enormous gouts of gas — sometimes irregularly-shaped, sometimes in a neat sphere. The latter is the case with the star above, a red giant called U Cam in the constellation Camelopardalis imaged by the Hubble Space Telescope.

From the Hubble image description:

U Cam is an example of a carbon star. This is a rare type of star whose atmosphere contains more carbon than oxygen. Due to its low surface gravity, typically as much as half of the total mass of a carbon star may be lost by way of powerful stellar winds. Located in the constellation of Camelopardalis (The Giraffe), near the North Celestial Pole, U Cam itself is actually much smaller than it appears in Hubble’s picture. In fact, the star would easily fit within a single pixel at the center of the image. Its brightness, however, is enough to saturate the camera’s receptors, making the star look much bigger than it really is.

The shell of gas, which is both much larger and much fainter than its parent star, is visible in intricate detail in Hubble’s portrait. While phenomena that occur at the ends of stars’ lives are often quite irregular and unstable, the shell of gas expelled from U Cam is almost perfectly spherical.

Image credit: ESA/NASA

Posted on by Nancy Atkinson

Astrophoto: Jupiter and Venus over São Paulo

A great reason to get up early these days is the pre-dawn show now available from Venus and Jupiter. The two brightest planets in the night sky are paired together in the eastern sky, and Ednilson Oliveira from São Paulo, Brazil got up early this morning, July 6, 2012, to take this gorgeous shot of the planetary duo in the constellation Taurus, hovering over the city.

His specs: Nikon D3100, 18 mm, F/6.3 – Texp = 3 s – ISO 3200.

Beautiful!

For more information about seeing Venus and Jupiter in the early morning skies, watch the video below from Science@NASA:

If you don’t watch the video in its entirety, one thing of note: Venus and the bright star Aldebaran will be right next to each other on the morning of July 9 — which will be a great sight.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Image caption: Jupiter and Venus in the constellation Taurus in the city of Sao Paulo. Credit: Ednilson Oliveira

Posted on by Nancy Atkinson

“Impossible” Binary Star Systems Found

Astronomers think about half of the stars in our Milky Way galaxy are, unlike our Sun, part of a binary system where two stars orbit each other. However, they’ve also thought there was a limit on how close the two stars could be without merging into one single, bigger star. But now a team of astronomers have discovered four pairs of stars in very tight orbits that were thought to be impossibly close. These newly discovered pairs orbit each other in less than 4 hours.

Over the last three decades, observations have shown a large population of stellar binaries, and none of them had an orbital period shorter than 5 hours. Most likely, the stars in these systems were formed close together and have been in orbit around each other from birth onwards.

A team of astronomers using the United Kingdom Infrared Telescope (UKIRT) in Hawaii made the first investigation of red dwarf binary systems. Red dwarfs can be up to ten times smaller and a thousand times less luminous than the Sun. Although they form the most common type of star in the Milky Way, red dwarfs do not show up in normal surveys because of their dimness in visible light.

But astronomers using UKIRT have been monitoring the brightness of hundreds of thousands of stars, including thousands of red dwarfs, in near-infrared light, using its state-of-the-art Wide-Field Camera (WFC).

“To our complete surprise, we found several red dwarf binaries with orbital periods significantly shorter than the 5 hour cut-off found for Sun-like stars, something previously thought to be impossible,” said Bas Nefs from Leiden Observatory in the Netherlands, lead author of the paper which was published in journal Monthly Notices of the Royal Astronomical Society. “It means that we have to rethink how these close-in binaries form and evolve.”

Since stars shrink in size early in their lifetime, the fact that these very tight binaries exist means that their orbits must also have shrunk as well since their birth, otherwise the stars would have been in contact early on and have merged. However, it is not at all clear how these orbits could have shrunk by so much.

One possible scenario is that cool stars in binary systems are much more active and violent than previously thought.

The astronomers said it is possible that the magnetic field lines radiating out from the cool star companions get twisted and deformed as they spiral in towards each other, generating the extra activity through stellar wind, explosive flaring and star spots. Powerful magnetic activity could apply the brakes to these spinning stars, slowing them down so that they move closer together.

“The active nature of these stars and their apparently powerful magnetic fields has profound implications for the environments around red dwarfs throughout our Galaxy, ” said team member said David Pinfield from the University of Hertfordshire.

UKIRT has a 3.8 meter diameter mirror, and is the second largest dedicated infrared telescope in the world. It sits at an altitude of 4,200 m on the top of the volcano Mauna Kea on the island of Hawaii.

Read the team’s paper.

Lead image caption: This artist’s impression shows the tightest of the new record breaking binary systems. Two active M4 type red dwarfs orbit each other every 2.5 hours, as they continue to spiral inwards. Eventually they will coalesce into a single star. Credit: J. Pinfield.

Posted on by Nancy Atkinson

Fireworks from the Sun

From July 2 to July 5, the Sun shot off a whopping eighteen M-class solar flares. Most originated from Active Region 1515 and ranged from M1.1 to M6.1. On July 4th alone, there were seven M-class solar flares. According to SpaceWeather.com, big sunspot AR1515 appears to be on the verge of producing an X-class explosion. NOAA forecasters estimate an 80% chance of M-flares and a 10% chance of X-flares during the next 24 hours.
Continue reading “Fireworks from the Sun”

Posted on by Nancy Atkinson

Powerful “Derecho” Storms as Seen from Space

The powerful windstorms that swept across the US last week was captured by several different satellites. This type of storm, called a derecho, moved from Illinois to the Mid-Atlantic states on June 29, and the movie from NOAA’s GOES-13 satellite shows the storms’ sudden expansion and speed. The storms left a more than 1,000-km (700-mile) trail of destruction across the Midwest and mid-Atlantic, cutting power to millions and killing thirteen people.

A derecho (pronounced “deh-REY-cho”) is not your average, ordinary local summer thunderstorm. These are widespread, long-lived but rare wind storms that are usually associated with a band of rapidly moving showers or thunderstorms. Damage from a derecho is usually in one direction along a relatively straight track. By definition an event is classified a derecho if the wind damage swath extends more than 400 km (240 miles) and includes wind gusts of at least 93 km/h (58 mph) or greater along most of its length.

These storms occur in the United States during the late spring and summer, with more than three quarters occurring between April and August.

The movie begins on June 28 at 15:15 UTC (11:15 a.m. EDT) and ends on June 30, 2012 at 16:01 UTC (12:01 p.m. EDT). In the animation, the derecho’s clouds appear as a line in the upper Midwest on June 29 at 14:32. By 16:02 UTC, they appear as a rounded area south of Lake Michigan. By 21:32, the area of the derecho’s clouds were near Lake Erie and over Ohio expanding as the system track southeast. By 06:30 UTC, the size appears to have almost doubled as the derecho moves over West Virginia, Maryland, Pennsylvania and Virginia. At 02:32 UTC on June 30 (10:32 p.m. EDT), the Derecho was over the mid-Atlantic bringing a 160 km (100 mile) line of severe storms and wind gusts as high as 144 km/h (90 mph) to the region.

“It is interesting how the process is a self-sustaining process that is fed by a combination of atmospheric factors that all have to be in place at the same time,” said Joe Witte, a meteorologist in Climate Change Communication at George Mason University, Va. and a consultant to NASA. “That is why they are relatively rare: not all the elements line up that often.”

NASA’s Aqua satellite flew over the derecho on June 29 and June 30, using the Atmospheric Infrared Sounder instrument (AIRS) onboard to capture infrared imagery of the event, as seen above.

“The AIRS infrared image shows the high near-surface atmospheric temperatures blanketing the South and Midwestern U.S., approaching 98 degrees Fahrenheit,” said Ed Olsen of the AIRS Team at NASA’s Jet Propulsion Laboratory.

The AIRS images for June 30 show areas of intense convection centered off the New Jersey coast and another, less intense, system over Iowa-Indiana-Ohio. The area off the New Jersey coast is no longer a rapidly moving linear front. The near-surface atmospheric temperatures over the South and Midwest had decreased by 10 to 15 Fahrenheit in most areas,” Olsen said.

NASA’s Suomi National Polar-orbiting Partnership satellite (NPP) captured night-time images on June 28 and June 30, that reflected the massive blackouts that occurred after the derecho swept through the mid-Atlantic states. You can see the comparison images here at NASA’s Earth Observatory website.

The mechanics of a derecho go like this: The downburst mentioned by Witte, above, occurs when cold air in the upper atmosphere is cooled more by the evaporation of some of the rain and melting of the frozen precipitation pushed up into the high levels of the towering cumulonimbus (thunderclouds). That cold air becomes much denser than the surrounding air and literally falls to the ground, accelerating like any other falling body.

“The huge blob of very cold air from the upper atmosphere has a higher forward wind speed since it is high in the atmosphere,” Witte said. “This gives the ‘blob’ great forward momentum. Add that speed to the falling speed and the result is a very powerful forward moving surface wind.”

The process of a derecho can become self-sustaining as hot and humid air is forced upward by the gust front and develops more (reinforcing) towering clouds. If there is a rear low level jet stream, there is nothing to stop the repeating process.

You can find out more information about derechos at this NOAA page.

Source: NASA

Posted on by Nancy Atkinson

Latest Panoramic View from Mars Rover

What’s a Mars rover to do when there’s not enough power to rove? Take pictures. LOTS of pictures! This wonderful new panoramic view of the Opportunity rover’s stopping place this past Mars winter, Greeley Haven, is composed of 817 images taken between Dec. 21, 2011, and May 8, 2012. It shows fresh rover tracks and the rim of an ancient impact crater, Endeavour, which awaits more explorations from Opportunity. You’ll want to click and see a bigger version of it here.

But to get the full effect, check out this great interactive sphere of the panorama put together by John O’Connor of the NASATech website!

The images were taken with the color camera mounted on the mast of Oppy, providing a sense of sitting on top of the rover and taking in the view. This is actually a false color image, which emphasizes the difference between the materials.

“The view provides rich geologic context for the detailed chemical and mineral work that the team did at Greeley Haven over the rover’s fifth Martian winter, as well as a spectacularly detailed view of the largest impact crater that we’ve driven to yet with either rover over the course of the mission,” said Jim Bell of Arizona State University, Tempe, Pancam lead scientist.

Opportunity has recently reached a milestone: On July 2, Opportunity reached its 3,000th Martian day, or Sol. You can read a great write-up of the accomplishment at the Road to Endeavour blog by Stu Atkinson, which includes interviews of rover drivers Scott Maxwell and Paolo Bellutta.

Stu also compiled this mosaic close-up of a RAT (Rock Abrasion Tool) hole drilled by Oppy into a rock called “Grasburg.”

Opportunity has recently started to take short drives coming off the long Martian winter, and the team notes in the latest update that the rover has been benefiting from solar array dust cleaning events, which increase the daily energy production: as of Sol 3001 (July 3, 2012), the solar array energy production was 577 watt-hours. That’s great news for future drives and the longevity of the long-lived rover, which has been on Mars since 2004. Truly, Oppy is the Energizer Bunny of rovers!

Lead image caption: This full-circle scene combines 817 images taken by the panoramic camera (Pancam) on NASA’s Mars Exploration Rover Opportunity. It shows the terrain that surrounded the rover while it was stationary for four months of work during its most recent Martian winter. Image Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.

Second image caption: A close-up look at a hole drilled by Opportunity’s RAT (Rock Abrasion Tool). Mosaic of 4 microscopic imager photos by Stu Atkinson.

Source: JPL

Posted on by Jason Major

The Case of the Disappearing Dust

Astronomy has always taught us that planets form from vast clouds of dust and gas orbiting young stars. It’s a gradual process of accretion that takes hundreds of thousands, perhaps even millions, of years… or does it?

During a 1983 sky survey with the Infrared Astronomical Satellite (IRAS) astronomers identified a young Sun-like star with a large cloud of dust surrounding it. The star, named TYC 8241 2652 1, is 450 light years away and what they had found around it was thought to be the beginnings of a solar system – the protoplanetary disc from which planets form.

Fast forward to 2008. Astronomers observed at the same star with a different infrared telescope, the Gemini South Observatory in Chile. What was observed looked a lot like what was previously seen in ’83.

Then, in 2009, they looked again. Curiously, the brightness of the dust cloud was only a third of what it was the year before. And in WISE observations made the very next year, it had disappeared entirely.

“It’s like the classic magician’s trick: now you see it, now you don’t. Only in this case we’re talking about enough dust to fill an inner solar system, and it really is gone.”

– Carl Melis, lead author and postdoctoral fellow at UC San Diego

Abracadabra?

“It’s as if you took a conventional picture of the planet Saturn today and then came back two years later and found that its rings had disappeared,” said study co-author and circumstellar disk expert Ben Zuckerman of UCLA.

It’s always been thought that planets take some time to form, in the order of hundreds of thousands of years. Although that may seem like forever to humans, it’s quick in cosmic time scales. But if what they’ve seen here with TYC 8241 is in fact planetary formation, well… it may happen a lot faster than anyone thought.

On the other hand, the star could have somehow blown all the dust out of the system. More research will be needed to see if that was the case.

The really interesting thing here is that astronomers have traditionally looked for these kinds of dust clouds around stars to spot planetary formation in action. But if planets form quicker than we thought, and the dust clouds are only fleeting features, then there may be a lot more solar systems out there that we can’t directly observe.

“People often calculate the percentage of stars that have a large amount of dust to get a reasonable estimate of the percentage of stars with planetary systems, but if the dust avalanche model is correct, we cannot do that anymore,” said study co-author Inseok Song, assistant professor of physics and astronomy at the University of Georgia. “Many stars without any detectable dust may have mature planetary systems that are simply undetectable.”

Read more in the news release from the University of Georgia.

Top image: Gemini Observatory/AURA artwork by Lynette Cook.