Dramatic Videos of Station Undocking, Gorgeous Earth Descent and Soyuz Touchdown by Russian American Trio

Soyuz Lands with the Moon as backdrop. Credit: NASA/Bill Ingalls


Video Caption: Soyuz Trio Lands in Kazakhstan – The Soyuz spacecraft carrying NASA astronaut Ron Garan and his fellow Expedition 28 flight engineers returned safely to Earth on Sept. 16 with a landing on the steppe of Kazakhstan. Garan and cosmonauts Andrey Borisenko, and Alexander Samokutyaev had been on the International Space Station since April 6. Their journey home was delayed just over a week by the failure of the Progress 44 cargo craft to reach the station. Remaining on the orbiting laboratory is NASA’s Mike Fossum and his two Expedition 28/29 colleagues, Russian Sergei Volkov, and Satoshi Furukawa of the Japanese Aerospace Exploration Agency

Check out this collection of dramatic videos of the departure, descent and safe touchdown of the trio of Russian and American space flyers aboard the Soyuz TMA 21 spacecraft in the remote steppes of Kazakhstan on Sept. 16, 2011.

The first video above is a compilation of all the key events from the Soyuz spacecraft undocking from the International Space Station (ISS) to landing and gives the complete picture. Be sure to watch the Soyuz flying away like a bird with the gorgeous Earth in the background. Observe the crew being extracted like fish from the capsule.

The rest of the videos are shorter and break down the story to focus on the key individual events of the crews remaining final hours aboard the station and in space.

This video records the “Change of Command” as Mike Fossum takes over the helm of the ISS

Video Caption: NASA’s Fossum Given ISS Command – In a ceremony conducted 230 miles above the Earth on Sept. 14, the “helm” of the International Space Station was handed over by Expedition 28 Commander Andrey Borisenko to NASA astronaut, Mike Fossum, who takes command of the orbiting laboratory on Expedition 29.

Hatch Closure and Bidding Farewell

Video Caption: Hatch Closes as Soyuz Crew Bids Farewell – The Expedition 28 crew of Soyuz Commander Alexander Samokutyaev, NASA Flight Engineer Ron Garan and off-going station Commander Andrey Borisenko said their goodbyes to the remaining residents of the International Space Station before closing the hatch on their vehicle and preparing to undock for their return home to Earth on Sept. 16

This video highlights the ISS undocking sequence

Video Caption: Soyuz Undocks from ISS – The Soyuz TMA-21 spacecraft that’ll carry Commander Alexander Samokutyaev, NASA Flight Engineer Ron Garan and off-going station Commander Andrey Borisenko back to Earth undocks from the International Space Station and begins its return journey home.

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Read Ken’s Soyuz landing story for further details:
Expedition 28 Soyuz Crew Lands Safely in Kazakhstan

Attention Public Relations: Here’s What Internet News Wants From You

This is a summary of a talk I gave recently. There was enough slack-jawed astonishment from public relations folks that I thought it might be helpful for others.

My name is Fraser Cain, and I’m the publisher of Universe Today. A space and astronomy news website read by more than 3 million people a month. We have 65,000 RSS subscribers and email readers. We’ve published about 25,000 articles on Universe Today over the last 12 years, and deeply understand what our readers want.

So, if you’re in public relations, and you want to reach out to publishers and news editors, to get them to publish your news, let me tell you what we want. Although I’ll give you examples for space/astronomy, I’m sure this is exactly the same in every news market on the internet.

We want scoops!
Continue reading “Attention Public Relations: Here’s What Internet News Wants From You”

Expedition 28 Soyuz Crew Lands Safely in Kazakhstan

Expedition 28 Lands. The Soyuz TMA-21 spacecraft is seen as it lands with Expedition 28 Commander Andrey Borisenko, and Flight Engineers Ron Garan, and Alexander Samokutyaev in a remote area outside of the town of Zhezkazgan, Kazakhstan, on Friday, Sept. 16, 2011. NASA Astronaut Garan, Russian Cosmonauts Borisenko and Samokutyaev are returning from more than five months onboard the International Space Station where they served as members of the Expedition 27 and 28 crews. Photo Credit: (NASA/Bill Ingalls)

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The three man Soyuz TMA-21 crew of cosmonauts and astronauts comprising of Commander Alexander Samokutyaev, Expedition 28 commander Andrey Borisenko and NASA flight engineer Ronald Garan made a pinpoint landing following a flawless descent and touched down safely in the southern steppes of Kazakhstan at 12:00 AM EDT today, Sept. 16, (10 AM local time), thereby wrapping up a nearly six month tour of duty at the International Space Station.

The Soyuz capsule landed on its side as it is frequently wont to do, about three hours after sunrise. The soft landing engines fired within seconds of touchdown to cushion the shock.

Soyuz TMA-21 lands safely in Kazakhstan on Sept. 16 with Russian-American trio of spaceflyers. Credit: NASA TV

A phalanx of twelve Russian search and recovery helicopters swooped in quickly after landing. The Russian forces had established two way communications and visual sighting with the space flyers in the last minutes of the descent.

Russian America Soyuz TMA-21 Crew after safe landing on Sept 16, 2011 and extraction from capsule. Expedition 28 Commander Andrey Borisenko, left, Flight Engineers Alexander Samokutyaev, center, and Ron Garan, sit in chairs outside the Soyuz Capsule just minutes after they landed in a remote area outside the town of Zhezkazgan, Kazakhstan, on Friday, Sept. 16, 2011. NASA Astronaut Garan, Russian Cosmonauts Borisenko and Samokutyaev are returning from more than five months onboard the International Space Station where they served as members of the Expedition 27 and 28 crews. Photo Credit: NASA/Bill Ingalls

Russian recovery team quickly reach the Soyuz TMA21 capsule after safe landing. Credit: NASA TV

Weather was perfect with very low winds, few clouds and warm temperatures of nearly 70 degrees Fahrenheit.

Altogether the trio spent 164 days in space, 162 of those were aboard the ISS. Their Soyuz capsule had docked at the ISS on April 7, 2011 following a two day trip after liftoff on April 5 from the Baikonur Cosmodome aboard a capsule dubbed Gagarin. The spaceship was named in honor of Yuri Gagarin, first human to orbit the Earth on the 50th anniversary of his courageous one orbit flight in April 1961 that inaugurated the Era of human spaceflight.

This crew lived aboard the ISS for the arrival of the final two history making flights of the Space Shuttle program as well as the anniversaries of Gagarin and America’s first astronaut in space, Alan Shepard.

Soyuz TMA 21 undocks from the ISS.

The helicopter recovery team arrived at the Soyuz capsule with seconds of touchdown and began erection of an inflatable medical tent. The Soyuz was rolled to facilitate the safe and proper extraction of the crew.

The astronauts and cosmonauts were quickly extracted from the capsule by the ground crew, checked by doctors and placed in recliners for the two hour trip back to a staging base in Karaganda, Kazakhstan for a traditional Kazakh welcome. Thereafter the crew will split up. Garan will be returning immediately to the US on a flight back to the Mission Control in Houston, Texas.

Soyuz departs

Just hours earlier this evening, the trio bagan the process of departing the ISS. They donned their Sokol launch and entry pressure suits, floated into the return capsule and closed the hatches between the Soyuz and the ISS.

Following leak checks the crew unhooked latches and undocked the Soyuz from the Poisk module at 8:38 p.m. while flying over northern China. Three minutes later thrusters were fired for 15 seconds to separate the two vehicles.

Left behind on the station was the Expedition 29 crew comprising Commander Mike Fossum from the US, cosmonaut Sergei Volkov from Russia and Japanese astronaut Satoshi Furukawa.

Soyuz landing in Kazakhstan on Sept 16, 2011. Credit: NASA TV

As the ISS and Soyuz were flying in tandem, the crew executed the 4 minutes 14 sec “de-orbit burn” which took place exactly on time at 11: 05 p.m. EDT. The critical Soyuz thruster burn slowed the ship by some 258 MPH and enabled the capsule to drop out of orbit, setting up the descent down through the Earth’s atmosphere.

Then the computer commanded pyrotechnic separation of the three Soyuz modules took place some 87 miles above Earth about 22 minutes later at 11:33 p.m., occurring just three minutes prior to re-entry into the Earth’s atmosphere over the heart of Africa.

Getting ready to open Soyuz hatch. Credit: NASA TV

The crew landed inside the central descent module less than an hour after completing the burn and less than 30 minutes after module separation.

The ISS will now be tended by only a three man crew for the next two months. That’s an unusually long time to maintain a reduced crew. But it’s all due to the recent failure of the third stage of the Russian Soyuz-U rocket lofting the Progress 44 cargo ship on Aug 24. The failure has been traced to a clogged fuel line. Russia is working to determine exactly how and why this could have happened and taking steps to prevent a repeat which would have disastrous consequences.

The next Soyuz blastoff is provisionally set for Nov.14 with a station arrival on Nov. 16. The three man crew of Anton Shkaplerov, Anatoly Ivanishin and NASA flight engineer Dan Burbank had originally been slated for Sept 22. But it was pushed back following the Progress launch failure.

Mike Fossom’s crew is scheduled to depart just 2 days later. Thus any further Soyuz launch delay wil require the ISS to be at least temporarily “de-manned” for the first time since continuous crewed operations started a dozen years ago.

Opening Soyuz hatch to cramped quarters. Credit: NASA TV

Construction Begins on the 1st Space-Bound Orion Crew Module

Construction on the first space-bound Orion Multi-Purpose Crew Module began with the first weld at the Michoud Assembly Facility on Sept. 9. 2011. This capsule will be used during Orion’s first test flight in space which could occur as early as 2013, possibly atop a Delta 4 Heavy booster. Credit: NASA

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Production of NASA’s first space-bound Orion crew module has at last begun at NASA’s Michoud Assembly Facility (MAF) in New Orleans – that’s the same facility that for more than three decades was responsible for manufacturing the huge orange colored External Tanks for the just retired Space Shuttle Program.

The first weld of structural elements of the Orion crew cabin was completed by Lockheed Martin engineers working at Michoud on Sept. 9, 2011. This marks a major milestone on the path toward the full assembly and first test flight of an Orion capsule.

This state of the art Orion vehicle also holds the distinction of being the first new NASA spacecraft built to blast humans to space since Space Shuttle Endeavour was assembled at a California manufacturing facility in 1991.

This capsule will be used during Orion’s first test flight in space which could occur as early as 2013. Credit: NASA

Eventually, Orion crew modules with astronaut crews will fly atop NASA’s newly announced monster rocket – the SLS – to exciting new deep space destinations beyond low Earth Orbit; such as the Moon, Asteroids and Mars.

“This marks the beginning of NASA’s next step to send humans far beyond Earth orbit,” said Orion program manager Mark Geyer. “The Orion team has maintained a steady focus on progress, and we now are beginning to build hardware for spaceflight. With this milestone, we enter the home stretch toward our first trip to space in this new vehicle.”

The first unmanned Orion test flight – dubbed OFT-1 – could come as early as 2013 depending on the funding available from NASA and the US Federal Government.

Welding the First Space-Bound Orion at NASA’s Michoud Assembly Facility in New Orleans by NASA and Lockheed Martin contractor team. Credit: NASA

NASA is still deciding which rocket to use for the initial test flight – most likely a Delta 4 Heavy but possibly also the new Liberty rocket proposed by ATK and EADS.

The framework welds were completed using the same type of friction stir welding (FSW) process that was implemented to construct the last several of the 135 Space Shuttle External Tanks at MAF that flew during the shuttle program.

Friction Stir Welding creates seamless welds in the Aluminum – Lithium alloys used for construction that are far stronger and more reliable and reproducible compared to conventional welding methods.

The first Space-Bound Orion will look similar to this initial Orion Ground Test Article (GTA) prototype crew cabin built in 2010 at NASA’s Michoud Assembly Facility, New Orleans, LA after individual segments were bound together by Friction Stir Welding techniques. Note the astronaut crew hatch and windows. The GTA is now undergoing testing and integration at Lockheed’s facilities in Denver, Colorado. Credit: Ken Kremer

Orion spacecraft will be manufactured at Michoud in New Orleans, Louisiana, then sent to the Operations & Checkout Facility at Kennedy Space Center for final assembly and integration prior to launch.

Lockheed Martin is the prime contractor for Orion. The vehicle was recently renamed the Orion Multipurpose Crew Vehicle (MPCV) after being resurrected following its cancellation by President Obama as a key element of NASA’s now defunct Project Constellation “Return to the Moon” program.

NASA's Orion Multi Purpose Crew Vehicle
The Orion MPVC Multi Purpose Crew Vehicle ground test article (GTA) is shown at the Lockheed Martin Vertical Test Facility in Colorado. The GTA’s heat shield and thermal protection backshell was completed in preparation for environmental testing. Credit: NASA/Lockheed Martin

The first crewed Orion won’t launch until the 2nd flight of the SLS set for around 2020 said William Gerstenmaier, NASA Associate Administrator for Human Exploration and Operations (HEO) Mission Directorate, at an SLS briefing for reporters on Sept. 14.

Lockheed has already built an initial version of the Orion crew capsule known as the Orion Ground Test Article (GTA) and which is currently undergoing stringent vibration and acoustics testing to mimic the harsh environments of space which the capsule must survive.

Watch for my upcoming Orion GTA status report.

Sketch of the Orion Multipurpose Crew Vehicle. Credit: NASA
Artists concept of the STS blasting off with the Orion Crew Module from the Kennedy Space Center. Credit: NASA

Read Ken’s continuing features about the Orion project and Orion GTA starting here:
First Orion Assembled at Denver, Another Orion Displayed at Kennedy Space Center
Lockheed Accelerates Orion to Achieve 2013 launch and potential Lunar Flyby

Milky Way Arm Wrestles With Dark Matter

Computer model of the Milky Way and its smaller neighbor, the Sagittarius dwarf galaxy. The flat disk is the Milky Way, and the looping stream of material is made of stars torn from Sagittarius as a result of the strong gravity of our galaxy. The spiral arms began to emerge about two billion years ago, when the Sagittarius galaxy first collided with the Milky Way disk. Image by Tollerud, Purcell and Bullock/UC Irvine

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For a good number of years, astronomers have hypothesized the Sagittarius Dwarf Galaxy has been loaded up with dark matter. As one of our nearest neighboring galaxies and part of our local group, Sag DEG has been hanging around for billions of years and may have orbited us as many as ten times. However, in order to survive the tidal strain of such interaction, this loop-shaped elliptical has got to have some muscle. Now UC Irvine astronomers are speculating on how these close encounters may have shaped the Milky Way’s spiral arms.

In a study released in today’s Nature publication, astronomers are citing telescopic data and computer modeling to show how our local galactic collision has sent streams of stars out in loops in both galaxies. These long streamers continue to collect stellar members and the rotation of the Milky Way forms them into our classic spiral pattern. The news is the presence of dark matter in Sag DEG is responsible for the initial push.

“It’s kind of like putting a fist into a bathtub of water as opposed to your little finger,” said James Bullock, a theoretical cosmologist who studies galaxy formation.

But the little Sagittarius Dwarf, as strong as the dark matter might be, isn’t going to win this cosmic arm wrestling match. Each time we interact, the small galaxy gets further torn apart and about all that’s left is four globular clusters and a smattering of old stars which spans roughly 10,000 light-years in diameter.

“When all that dark matter first smacked into the Milky Way, 80 percent to 90 percent of it was stripped off,” explained lead author Chris Purcell, who did the work with Bullock at UCI and is now at the University of Pittsburgh. “That first impact triggered instabilities that were amplified, and quickly formed spiral arms and associated ring-like structures in the outskirts of our galaxy.”

Will we meet again? Yes. The Sagittarius galaxy is due to strike the southern face of the Milky Way disk fairly soon, Purcell said – in another 10 million years or so.

Original Story Source: University of Irvine News. Further Reading: The Sagittarius impact as an architect of spirality and outer rings in the Milky Way.

SLS: NASA’s Next Big Thing

Artist's concept of the new SLS on the launch pad. Credit: NASA

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NASA has officially unveiled the plan for their next large-scale rocket: the Space Launch System, or SLS, will provide heavy-lift capabilities for cargo and spacecraft to go beyond low-Earth orbit and is proposed as a safe, sustainable and efficient way to open up the next chapter in US space exploration.

SLS is designed to carry the Orion Multi-Purpose Crew Module, NASA’s next-generation human spaceflight vehicle that is specifically designed for long-duration missions. (Construction of the first space-bound MPCV began last week on September 9.)

Utilizing a modular design that can accommodate varying mission needs, SLS will also be able to provide service to the International Space Station.

“President Obama challenged us to be bold and dream big, and that’s exactly what we are doing at NASA. While I was proud to fly on the space shuttle, tomorrow’s explorers will now dream of one day walking on Mars.”

– NASA Administrator Charles Bolden

SLS will have an initial lift capacity of over 70 metric tons – about 154,000 pounds (70,000 kg). That’s three times the lift capability of the space shuttles! In the event of a Mars mission that can be upgraded to 130 metric tons – about the weight of 75 SUVs.

Artist image of SLS launch. Credit: NASA

The first developmental flight is targeted for the end of 2017.

SLS will be the first exploration-class vehicle since the giant Saturn V rockets that carried the Apollo astronauts to the Moon. Using rocket technology developed during the shuttle era and modified for the canceled Constellation program, combined with cutting-edge manufacturing processes, SLS will expand the boundaries of human spaceflight and extend our reach into the solar system.

“This launch system will create good-paying American jobs, ensure continued U.S. leadership in space, and inspire millions around the world,” NASA Administrator Charles Bolden said. “President Obama challenged us to be bold and dream big, and that’s exactly what we are doing at NASA. While I was proud to fly on the space shuttle, tomorrow’s explorers will now dream of one day walking on Mars.”

Read the NASA news release here.

(And check out this “Fun Facts” sheet on SLS.)

Kepler Mission Discovers “Tatooine-like” Planet

Artist's rendering of Kepler-16b Image Credit: NASA/JPL-Caltech/R. Hurt

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In a news conference today, Kepler mission scientists announced the first confirmed circumbinary planet ( a planet that orbits a binary star system). The planet in question, designated Kepler-16b has been compared to the planet Tatooine from the Star Wars saga.

Would it be possible for someone like Luke Skywalker to stand on the surface of Kepler-16b and see the famous “binary sunset” as depicted in Star Wars?

Despite the initial comparison between Kepler-16b and Tatooine, the planets really only have their orbit around a binary star system in common. Kepler-16b is estimated to weigh about a third the mass of Jupiter, with a radius of around three-quarters that of Jupiter.

Given the mass and radius estimates, this makes Kepler-16b closer to Saturn than the rocky, desert-like world of Tatooine. Kepler-16b’s orbit around its two parent stars takes about 229 days, which is similar to Venus’ 225-day orbit. At a distance of about 65 million miles from its parent stars, which are both cooler than our sun, temperatures on Kepler-16b are estimated in the range of around -100 C.

The team did mention that Kepler-16b is just outside of the habitable zone of the Kepler-16 system. Despite being just outside the habitable zone, the team did mention that it could be possible for Kepler-16b to have a habitable moon, if said moon had a thick, greenhouse gas atmosphere.

Binary Sunset as seen on Tatooine
Tatooine appears to have twin stars like our sun, versus the orange (type K) and red (type M) stars of Kepler-16
During the press conference John Knoll, visual effects supervisor at ILM, mentioned: “When I was a kid, I didn’t think it was going to be possible to make discoveries like this.” Knoll also added, “The science is stranger and cooler than fiction!”

The Kepler mission detects exoplanet candidates by using the transit method which detects the dimming of the light emitted from a star as a planet crosses in front of it. In the case of Kepler-16b, the detection was complicated by the two stars in the system eclipsing each other.

The system’s brightness showed variations even when the stars were not eclipsing each other, which hinted at a third body. What further complicated matters was that the variations in brightness appeared at irregular time intervals. The irregular time intervals hinted that the stars were in different positions in their orbit each time the third body passed. After studying the data, the team came to the conclusion that the third body was orbiting, not just one, but both stars.

“Much of what we know about the sizes of stars comes from such eclipsing binary systems, and most of what we know about the size of planets comes from transits,” added Kepler scientist Laurance Doyle of the SETI Institute. “Kepler-16 combines the best of both worlds, with stellar eclipses and planetary transits in one system.” Doyle’s findings will be published in the Sept. 15th issue of the journal Science.

The Kepler mission is NASA’s first mission capable of finding Earth-size planets in or near the habitable zone – the region around a star where liquid water can exist on the surface of an orbiting planet. A considerable number of planets and planet candidates have been detected by the mission so far. If you’d like to learn more about the Kepler mission, visit: http://kepler.nasa.gov/

You can also read more about the Kepler-16b discovery at: http://kepler.nasa.gov/Mission/discoveries/kepler16b/

Source: NASA news conference / NASA TV

Ray Sanders is a Sci-Fi geek, astronomer and space/science blogger. Visit his website Dear Astronomer and follow on Twitter (@DearAstronomer) or Google+ for more space musings.

Solo Star Synthesis

Young binary stars. Image credit: NASA

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“Swing your partner round and round… Out of the cluster and out of town” While that’s a facetious description as to how binary stars end up losing their companions, it’s not entirely untrue. In practicing the field of astronomy, we’re quite aware that not all stars are single entities and at least half of the stellar population of the Milky Way consists of binaries. However, explaining just exactly why some are loners and others belong to multiple systems has been somewhat of a mystery. Now a team of astronomers from Bonn University and the Max-Planck-Institute for Radio astronomy think they have the answer…

The team recently published their results in a paper in the journal Monthly Notices of the Royal Astronomical Society. Apparently the environment that forms a particular group of stars plays a huge role in how many stars lead a lone existence – or have one or more companions. For the most part, star-forming nebulae produce binary stars in clustered groups. These groups then quickly disband into their parent galaxy and at least half of them become loners. But why do some double stars end up leading a solitary life? The answer might very well be how they interact gravitationally.

“In many cases the pairs are torn apart into two single stars, in the same way that a pair of dancers might be separated after colliding with another couple on a crowded dance floor”, explains Michael Marks, a PhD student and member of the International Max-Planck Research School for Astronomy and Astrophysics.

If this is the case, then single stars take on that state long before they spread out into a galaxy. Since conditions in star-forming regions vary widely in both appearance and population, science is taking a closer look at density. The more dense the region is, the more binary stars form – and the greater the interaction that splits them apart. Every cluster of stars has a different population, too.. And that population is dependant on the initial density. By using computer modeling, astronomers are able to determine what regions are most likely to contribute single stars are multiple systems to their host galaxy.

“Working out the composition of the Milky Way from these numbers is simple: We just add up the single and binary stars in all the dispersed groups to build a population for the wider galaxy”, says Kroupa. Michael Marks further explains how this concept applies universally: “This is the first time we have been able to compute the stellar content of a whole galaxy, something that was simply not possible until now. With our new method we can now calculate the stellar contents of many different galaxies and work out how many single and binary stars they have.”

Original Story Source: RAS News. For further reading: Notices of the Royal Astronomical Society. Animations of the interactions of binary stars.

Help! My Stars are Leaking!

A fast-moving star, Alpha Camelopardalis, creates a stunning bow shock in this new image from WISE. Credit: NASA/JPL-Caltech/WISE Team

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Star clusters are wonderful test beds for theories of stellar formation and evolution. One of the key roles they play is to help astronomers understand the distribution of stellar masses as stars form (in other words, how many high mass stars versus intermediate and low mass stars), known as the Initial Mass Function (IMF). One of the problems is that this is constantly evolving away from the initial distribution as stars die or are ejected from the cluster. As such, understanding these mechanisms is essential for astronomers looking to backtrack from the current population to the IMF.

To assist in this goal, astronomers led by Vasilii Gvaramadze at the University of Bonn in Germany are engaged in a study to search young clusters for stars in the process of being ejected.

In the first of two studies released by the team so far, they studied the cluster associated with the famous Eagle Nebula. This nebula is well known due to the famous “Pillars of Creation” image taken by the aging Hubble Space Telescope which shows towers of dense gas currently undergoing star formation.

Two main methods exist for discovering stars on the lam from their birthplace. The first is to examine stars individually and analyze their motion in the plane of the sky (proper motion) along with their motion towards or away from us (radial velocity) to determine if a given star has sufficient velocity to escape the cluster. While this method can be reliable, it suffers because the clusters are so far away, even though the stars could be moving at hundreds of kilometers per second, it takes long periods of time to detect it.

Instead, the astronomers in these studies search for runaway stars by the effects they have on the local environment. Since young clusters contain large amounts of gas and dust, stars plowing through it will create bow shocks, similar to those a boat makes in the ocean. Taking advantage of this, the team searched the Eagle Nebula cluster for signs of bow shocks from these stars. Searching images from several studies, the team found three such bow shocks. The same method was used in a second study, this time analyzing a lesser known cluster and nebula in Scorpius, NGC 6357. This survey turned up seven bow shocks of stars escaping the region.

In both studies, the team analyzed the spectral types of the stars which would indicate their mass. Simulations of nebulae suggested that the majority of ejected stars are given their initial kick as they have a close pass to the center of a cluster where the density is the highest. Studies of clusters have shown that their centers are often dominated by massive O and B spectral type stars which would mean that such stars would be preferentially ejected. These two studies have helped to confirm that prediction as all of the stars discovered to have bow shocks were massive stars in this range.

While this method is able to find runaway stars, the authors note that it is an incomplete survey. Some stars may have sufficient velocity to escape, but still fall under the local sound speed in the nebula which would prevent them from creating a bow shock. As such, calculations have predicted that roughly 20% of escaping stars should create detectable bow shocks.

Understanding this mechanism is important because it is expected to play the dominant role in the evolution of the mass distribution of clusters early in their life. An alternative method of ejection involves stars in a binary orbit. If one star becomes a supernova, the sudden mass loss suddenly decreases the gravitational force holding the second star in orbit, allowing it to fly away. However, this method requires that a cluster at least be old enough for stars to have evolved to the point they explode as supernova, delaying this mechanism’s importance until at least that point and allowing the gravitational sling-shot effects to dominate early on.

Stellar X-Rays Strip Planet To Bare Bones

Credit: X-ray: NASA/CXC/Univ of Hamburg/S.Schröter et al; Optical: NASA/NSF/IPAC-Caltech/UMass/2MASS, UNC/CTIO/PROMPT; Illustration: NASA/CXC/M.Weiss

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Some 880 light years away, a star named CoRoT-2a is busy decimating one of its planets – CoRoT-2b. Orbiting the parent star at a distance of over two million miles is dangerous business in this cosmic neighborhood. While the intrepid exoplanet might be about a thousand times the size of Earth right now, it’s getting about five million tons of matter stripped away from it every second. Thanks to new data from NASA’s Chandra X-ray Observatory and the European Southern Observatory’s Very Large Telescope, we’re able to take a closer look at this high-energy process for an even better understanding of how planets may – or may not – survive the process of forming a solar system.

“This planet is being absolutely fried by its star,” said Sebastian Schroeter of the University of Hamburg in Germany. “What may be even stranger is that this planet may be affecting the behavior of the star that is blasting it.”

Discovered by the French Space Agency’s Convection, Rotation and planetary Transits (CoRoT) satellite in 2008, this hot system is estimated to be between about 100 million and 300 million years old. The active parent star is assumed to be completely formed, yet its high magnetic activity is producing a bright x-ray signature comparable to that of a younger star. What could be causing the deviation that racks CoRoT-2b with a hundred thousand times more radiation than we receive from Sol?

“Because this planet is so close to the star, it may be speeding up the star’s rotation and that could be keeping its magnetic fields active,” said co-author Stefan Czesla, also from the University of Hamburg. “If it wasn’t for the planet, this star might have left behind the volatility of its youth millions of years ago.”

However, CoRoT-2a might not be alone. There’s a possibility that it’s a binary system with the companion positioned at roughly a thousand AU. If so, why can’t the x-ray instruments detect it? The answer is… it is not feeding on a planet to keep it active. CoRoT-2b’s huge size and proximity make for an intriguing combination. For as long as it lasts…

“We’re not exactly sure of all the effects this type of heavy X-ray storm would have on a planet, but it could be responsible for the bloating we see in CoRoT-2b,” said Schroeter. “We are just beginning to learn about what happens to exoplanets in these extreme environments.”

Original Story Source: Chandra News. For further reading: The corona and companion of CoRoT-2a. Insights from X-rays and optical spectroscopy.