The Shocking Behavior of a Speedy Star

Roguish runaway stars can have a big impact on their surroundings as they plunge through the Milky Way galaxy. Their high-speed encounters shock the galaxy, creating arcs, as seen in this newly released image from NASA’s Spitzer Space Telescope. In this case, the speedster star is known as Kappa Cassiopeiae, or HD 2905 to astronomers. It is a massive, hot supergiant moving at around 2.5 million mph relative to its neighbors (1,100 kilometers per second). But what really makes the star stand out in this image is the surrounding, streaky red glow of material in its path. Such structures are called bow shocks, and they can often be seen in front of the fastest, most massive stars in the galaxy. Bow shocks form where the magnetic fields and wind of particles flowing off a star collide with the diffuse, and usually invisible, gas and dust that fill the space between stars. How these shocks light up tells astronomers about the conditions around the star and in space. Slow-moving stars like our sun have bow shocks that are nearly invisible at all wavelengths of light, but fast stars like Kappa Cassiopeiae create shocks that can be seen by Spitzer’s infrared detectors. > More information

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USAF Launches Fifth GPS Block IIF satellite aboard Delta IV

The U.S. Air Force successfully launched a United Launch Alliance Delta IV-Medium rocket carrying the fifth Global Positioning System IIF satellite at 8:59 p.m. EST Feb. 20, from Space Launch Complex 37 here.

The GPS Block IIF satellites are built by Boeing, and are operated by the United States Air Force following their launch by United Launch Alliance, using Evolved Expendable Launch Vehicles.

The first GPS IIF satellite was launched on May 27, 2010, and entered service on Aug. 26, 2010.
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GPS IIF-5 Successfully Launched from Cape Canaveral AFS

The U. S. Air Force successfully launched the fifth Global Positioning System (GPS) IIF satellite carried aboard a United Launch Alliance Delta IV launch vehicle at 8:59 p.m. EST from Cape Canaveral Air Force Station, Fla., Feb. 20.

The Boeing-built GPS IIF satellite will join the GPS constellation providing world class space-based positioning, navigation and timing capabilities to support users around the globe. The new capabilities of the IIF satellites will provide greater navigational accuracy through improvements in atomic clock technology, a more robust signal for commercial aviation and safety-of-life applications, known as the new third civil signal (L5), a second civil signal (L2C) available for the dual frequency GPS receivers and a 12-year design life providing long-term service. These upgrades improve anti-jam capabilities for the warfighter and improve security for military and civil users around the world.
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Proba-2 view of post-eruptive loops on Sun

ESA’s Sun-watching Proba-2 minisatellite shows the aftermath of 18 February’s ‘coronal mass ejection’. 

Acquired at 0445 GMT, a little more than three hours after the initial eruption, the image demonstrates the Sun’s magnetic field reconnecting in the form of loops. Look down and left of the centre of the solar disc to clearly see this distinctive belt of loops.

Coronal mass ejections are powered by energy stored in the magnetic field of the Sun’s corona. This energy that can be released by the process of reconnection, in which oppositely oriented field lines are reconfigured to a more relaxed state and stored magnetic energy is converted into the heat and kinetic energy needed to drive huge outward eruptions.

Fields that have recently reconnected are heated to many millions of degrees, then cooling to the one million degree temperatures that are visible to Proba-2’s SWAP imager. A second Proba-2 sensor, LYRA, measures the Sun’s energy intensity at the same time. Both instruments are operated for ESA by the Royal Observatory of Belgium.

To see a movie of the 18 February CME and its aftermath, click here.

All the latest solar images from ESA and NASA are fed to the Helioviewer website, where you can make your own images and animations – see here.

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