IGR J11014-6103: The Space Olympics

Narrator (April Hobart, CXC): Nothing in space stays still. In fact, most stars are like long-distance marathon runners, as they are constantly moving in space throughout their lifetimes. However, astronomers have recently spotted a star (shown in this new space photo as a green smudge in the box) that is better at sprint running.

To work out the speed of this star, astronomers had to figure out how far it has travelled since it started its race and how long this took. Astronomers think the star began its race at the center of the purple cloud of gas and dust in the photo. That's because this is a special type of star that rotates very quickly, which is called a pulsar. And the pulsar was ejected during the explosion that created the cloud of gas and dust.

Based on their estimates, the astronomers think the pulsar is moving at an incredible speed of between 5 million and 7 million miles per hour! This could make it the fastest moving pulsar ever known! But there is a competitor for the title, as another pulsar has previously been estimated to be moving between 3 and 6 million miles per hour.

It's a pity astronomers can't enter these two stars into a 'Space Olympics' to determine which one is the fastest sprinter. Instead, they need to work it out the hard way and fine-tune their results.

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Narrator (April Hobart, CXC): HD 189733b: An exoplanet in orbit around a star about 63 light years from Earth. It has been nearly two decades since the first exoplanets – that is, planets around stars other than our Sun – were discovered. Now for the first time, X-ray observations have detected an exoplanet passing in front of its parent star. The observations, made by NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory, took advantage of the alignment of a planet and its parent star in HD 189733. This alignment enabled the observatories to observe a dip in X-ray intensity as the planet moved in front of, or transited, the star. This technique is the one used so successfully at optical wavelengths by NASA's Kepler telescope. In earlier studies using optical light, astronomers discovered that the main star in the HD 189733 system had what is known as a "hot Jupiter" around it. This means the planet is about the size of Jupiter, but in very close orbit around its star. The planet – that has been named HD 189733b -- is over 30 times closer to its star than Earth is to the Sun, and goes around the star once every 2.2 days. The new X-ray data suggest that this planet has a larger atmosphere than previously thought. This, in turn, may imply that radiation from the parent star is evaporating the atmosphere of HD 189733b more quickly than expected. The results on HD 189733 demonstrate how we need information from many different telescopes that detect different types of light to get a fuller picture of these mysterious worlds that we are now able to explore.

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