Skip to main content

Scientists Catch An X-Ray Eclipse Of A Planet Where It Rains Glass

Earlier this month, astronomers using the Hubble Space Telescope studied exoplanet HD 189733b and determined that it was a deep blue color, thanks to silicates in its atmosphere that can create storms akin to raining glass.
Now astronomers using NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM Newton Observatory have managed to catch sight of the planet as it eclipsed its sun using X-rays. This marks the first time that a planet has ever been observed in this manner.
This is actually similar to how HD 189733b was discovered in the first place. In 2005, French astronomers observed the planet transit in front of its star using the normal optical wavelengths that our eyes use. Indeed, most planets outside of our solar system have been discovered in this manner. When a planet transits, it causes part of the star’s brightness to dim as the planet passes in front of the star. Similarly, astronomers at Chandra and Newton viewed the planet pass in front of the star using X-ray wavelengths, noting a visible “dip” in the X-ray intensity of the planet’s star where HD 189733b passed in front of it.
Located about 63 light years from Earth, HD 189733b is about the size of Jupiter, but is much closer to its star – so close that a “year” on the planet is only about 2.2 days. Surface temperatures on the side facing its star reach 2,000 degrees and scientists in 2007 estimated that its winds probably reach up to 4,500 miles per hour.
By observing the transit of the planet using X-rays, the astronomers were able to learn even more about the composition for the planet. First, they discovered that its atmosphere is most likely much larger than originally estimated. They could tell that because the atmosphere of a planet blocks X-rays, but not normal light. In this case, the planet blocked about 2-3 times as big an area of X-rays as it did optical light, meaning the atmosphere extends out quite further. They also ascertained that as a result, the planet is losing its atmosphere at a very fast rate over time.
“That means that the planet’s atmosphere blocks X-rays at altitudes of more than 60,000 km above its optical radius – a 75% larger radius in X-rays!” wrote lead author Katja Poppenhaeger in a blog post. “That is pretty big, and I calculated that the outer atmosphere has to be heated up to about 20,000 K to sustain itself at such high altitudes. The bigger X-ray radius also means that the planet loses its atmosphere about 40% faster than thought before.”
The astronomers’ paper is published in the current issue of the Astrophysical Journal, but they’re not done with X-ray transit observations by a long shot.
“I’d like to know if the X-ray radius of other hot exoplanets is extended as well – and if yes, does the extent depend on the heating of the planet by the host star, or more on things like the overall density of the planet?” she wrote in her blog post. “Together with my former colleagues from Hamburg Observatory, we will test this for the even hotter Jupiter CoRoT-2b, using XMM-Newton. Personally, I’d like it best if the CoRoT-2b experiment had a completely surprising outcome as well – we’ll know next year!”

Comments

Popular posts from this blog

Windows 10 now on 600 million machines.

Microsoft CEO Satya Nadella told shareholders that Windows 10 has now passed 600 million monthly active users, picking up 100 million since May of this year. This number counts all Windows 10 devices used over a 28-day period. While most of these will be PCs, there are other things in the mix there: a few million Xbox Ones, a few million Windows 10 Mobile phones, and special hardware like the HoloLens and Surface Hub. The exact mix between these categories isn't known, because Microsoft doesn't say. The company's original ambition (and sales pitch to developers) was to have one billion systems running Windows 10 within about three years of the operating system's launch. In July last year, the company acknowledged that it won't hit that target—the original plan called for  50 million or more phone sales a year , which the retreat from the phone market has made impossible. But at the current rate it should still be on track for somewhere in excess of 700 million use...

Mayweather's Marriage Proposal -- I'll Love You Forever ... But Your Attitude Sucks!

It's what every little girl dreams of ... a marriage proposal over text message ... complete with crazy Hollywood bribes and a demand that you change your crappy attitude, stat.  And that's exactly what Floyd Mayweather fired off to Shantel Jackson back in April '14 ... according to new court docs obtained by TMZ Sports.  Jackson put the proposal on display in new legal papers filed in her nuclear war with her ex-fiancee ... which shows how Floyd tried to convince Shantel into getting engaged for a 2nd time.  "This is what I offer to you. Let's get married move in together you can go back in forth to L.A and stay at the condo." "I promise I will get you in 3 A list movies this year and I'm willing to go to counseling to make us work and you can get the stuff you want and I'm willing to change but I need you to have a better attitude." How romantic, right?! Shantel says she shot down the offer (shocker) ... and included several t...

WZoneLite – A Pretty Cool WooCommerce Amazon Affiliate Plugin .

Everyone wants to make a million dollars by being a blogger. The promise of riches and internet fame is a big draw to doing it for a lot of people, and I’m sorry to say that the reality of being a blogger (even a professional blogger!) is not quite…as financially lucrative as all that. But that’s not to say that it  can’t be –one of the best ways to start your empire is with an Amazon affiliate plugin. For me, the Amazon Associates program has been one of the biggest earners for me over the years. Not only are there CPM ads like Google Adsense (you know, the normal banner ads we all love to hate), but any time someone clicks a link from your site, you get a percentage of  anything  they buy while the token from your site lasts in their browser. If they buy a song, you get a few cents. If they buy a new MacBook Pro and iPhone? You get…a lot more cents. With that in mind, WZoneLite is a  pretty cool WooCommerce Amazon affiliate plugin that syncs everything together s...