An international team of scientists have taken the first ever photos of a system of planets orbiting another star. The pictures, released today, provide the first visual proof that alien worlds exist.
The photos, taken with the giant Gemini North telescope and neighbouring W M Keck Observatory on a mountaintop in Hawaii, shows a new solar system in the constellation of Pegasus, the flying horse.
Three planets, each much larger than Jupiter, can be clearly seen in the pictures orbiting their own sun – a star called HR 8799, which is around 60 million years old and 130 light-years away from Earth.
Observations over several months confirmed that they were moving with and travelling around the star which is also circled by dust. Two of the planets, labelled b and c, are visible in the image on the right which has the central star hidden.
Around 300 so-called extrasolar planets have been discovered in recent years but their existence has been detected by such things as a wobble in the starlight and they have never been directly seen. A previous picture, said to be of an extrasolar planet, has not been confirmed.
Dr Jenny Patience, of the University of Exeter, in England, was part of the team that made the new discovery. She told Skymania News: “We’ve been trying to capture images of extrasolar planets around stars for many years and now we have pictures of three at once.
“This is a really nice result. It is a chance to study young planets – they are much bigger than Jupiter and still very hot so the conditions will not be right yet for life.
“But our discovery makes this star a prime target now for finding smaller Earth-like planets. We’ll be extending the search too to other stars. The hunt for other planets to discover how common solar systems like our are in space is incredibly exciting.”
By coincidence, NASA scientists revealed today that the Hubble space telescope has photographed a planet too, around Fomalhaut, one of the brightest stars in the sky.
The Hubble image shows a planet shaping a disk of dust around Fomalhaut, which is 200 million years old and lies just 25 light-years away in the constellation of Piscis Austrinus, the Southern Fish.
The planets in the Gemini North pictures were revealed using a technique called adaptive optics that removes the “twinkling” of starlight caused by turbulence in our own atmosphere. See the full Gemini release here.
No such problems faced Hubble, high in orbit above the atmosphere. But in both cases the blinding light of the star had to be masked out because it was millions of time brighter than the planets.
Hubble’s photo shows a disk of ice and dust, similar to a band called the Kuiper Belt in our own solar system, which was first pictured in 2004. Now the new planet has been photographed 3 billion kilometers inside the ring’s inner edge. Images taken 21 months apart show how far it has moved in its orbit around Fomalhaut. See the Hubble release here.
Both the stars with new planets are much younger than the sun which is around 4 billion years old and half way through its life. Their planets are therefore likely to be at a much younger stage of evolution.