Glowing planet is really hot news

Space scientists have discovered the hottest planet ever identified in the galaxy. The world, which is slightly smaller than Saturn, is glowing red like a cigarette butt.

An artist's impression of the glowing planetLabelled HD 149026b, the planet radiates heat at an astonishing 3,700 Fahrenheit according to the Florida team who found it.

They were unable to see it separately from its parent star in the constellation of Corona Borealis, the Northern Crown.

However they were able to measure the dimming of the starlight when the planet disappeared behind it, using a heat-seeking infrared space telescope called Spitzer.

From this information they could work out how much light the planet itself emits. As I recently reported, it is astonishing how much we are learning from these tiny pinpricks of light.

Discovery team leader Professor Joseph Harrington, of the University of Central Florida, said: “HD 149026b is simply the most exotic, bizarre planet. It’s pretty small, really dense, and now we find that it’s extremely hot.”

Astronomers have so far found more than 230 planets around other stars, including Gliese 581, announced last month, the first that could resemble Earth with a rocky surface and oceans. Water vapour was detected in the atmosphere of another world and scientists say it is only a matter of time before they can analyse plant life on an alien planet!

HD 149026b is only the fourth so-called exoplanet to have its temperature taken. Experts say that to be so hot, it must absorb virtually all the heat of its own sun that reaches it, making its surface blacker than charcoal.

Professor Harrington said: “The high heat would make the planet glow slightly, so it would look like an ember in space, absorbing all incoming light but glowing a dull red.”

Nasa’s Drake Deming, of the Goddard Space Flight Center, Maryland, who co-authored a paper on the discovery for the journal Nature, said: “This planet is off the temperature scale that we expect for planets, so we don’t really understand what’s going on. There may be more big surprises in the future.”

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Paul Sutherland

Paul Sutherland

I have been a professional journalist for nearly 40 years. I write regularly for science magazines including BBC Sky at Night magazine, BBC Focus, Astronomy Now and Popular Astronomy. I have also authored three books on astronomy and contributed to others.
Paul Sutherland

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Paul Sutherland

I have been a professional journalist for nearly 40 years. I write regularly for science magazines including BBC Sky at Night magazine, BBC Focus, Astronomy Now and Popular Astronomy. I have also authored three books on astronomy and contributed to others.

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