Hubble Takes First Visible Light Image of Extrasolar Planet

by Nancy Atkinson on November 13, 2008

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Fomalhaut and orbiting planet.  Credit: NASA, ESA and P. Kalas (University of California, Berkeley, USA)

Fomalhaut and orbiting planet. Credit: NASA, ESA and P. Kalas (University of California, Berkeley, USA)

Persistence has paid off for astronomer Paul Kalas. After eight years and taking repeated photographs with the Hubble Space Telescope of a nearby star, he finally has what he and many astronomers have been striving for: the first visible-light snapshot of a planet outside our solar system. This coincides with the announcement of the first time astronomers have taken pictures of another multi-planet solar system, using the Gemini and Keck Telescopes. Kalas has been studying the star Fomalhaut, located about 25 light years from Earth, for several years. He knew the planet was there, because its perturbations were evident in the ring of gas and dust surrounding the star. The planet is probably close to the mass of Jupiter, and it orbits Fomalhaut at a distance about four times that between Neptune and the sun. Formally known as Fomalhaut b, the planet could have a ring system about the dimension of Jupiter’s early rings, before the dust and debris coalesced into the four Galilean moons. Learn more in the video below…

The planet’s existence was suspected in 2005, when images Kalas took with the Hubble Space Telescope’s Advanced Camera for Surveys showed a sharply defined inner edge to the dust belt around Fomalhaut, in the southern constellation Piscus Austrinus. The sharp edge and off-center belt suggested to Kalas that a planet in an elliptical orbit around the star was shaping the inner edge of the belt, much like Saturn’s moons groom the edges of its rings.

“The gravity of Fomalhaut b is the key reason that the vast dust belt surrounding Fomalhaut is cleanly sculpted into a ring and offset from the star,” Kalas said. “We predicted this in 2005, and now we have the direct proof.”

Check out this video from ESA about the discovery:

“It will be hard to argue that a Jupiter-mass object orbiting an A star like Fomalhaut is anything other than a planet,” said coauthor James R. Graham, professor of astronomy at UC Berkeley. “That doesn’t mean it’s exactly what we expected when we went hunting for planets in this system.”

“Every planet has a chaotic zone, which is basically a swath of space that encloses the planet’s orbit and from which the planet ejects all particles,” said Eugene Chiang, a UC Berkeley associate professor of astronomy and of earth and planetary science, and first author of the ApJ paper. “This zone increases with the mass of the planet, so, given the size of the chaotic zone around Fomalhaut b, we can estimate that its likely mass is in the vicinity of one Jupiter mass.”

Fomalhaut annotated.  Credit: Credit: NASA, ESA, and Z. Levay (STScI)

Fomalhaut annotated. Credit: Credit: NASA, ESA, and Z. Levay (STScI)

Kalas now has two photographs of the planet, taken in 2004 and 2006, which show that its movement over a 21-month period exactly fits what would be expected from a planet orbiting Fomalhaut every 872 years at a distance of 119 astronomical units, or 11 billion miles. One astronomical unit (AU) is the average distance between the Earth and the sun, or 93 million miles.

“I nearly had a heart attack at the end of May when I confirmed that Fomalhaut b orbits its parent star,” Kalas said. “It’s a profound and overwhelming experience to lay eyes on a planet never before seen.”

Sources: EurekAlert, ESA’s Space Telescope site


Nancy Atkinson is Universe Today's Senior Editor. She also is the host of the NASA Lunar Science Institute podcast and works with Astronomy Cast. Nancy is also a NASA/JPL Solar System Ambassador.

ed November 15, 2008 at 7:07 PM

They discovered the star 1RXS J160929.1-219524 on 1998 the “planet” as they called was identified in 2008.
2M1207b was identified in infrared spectrum september 2004 and it was assumed a “planet” because it had and inferred mass less than that of a brown dwarf.
Fomalhaut B was identified also identified in 2004 but it was in the visible light spectrum. So it is indeed the first of its kind in the visible spectrum.

bse5150 November 16, 2008 at 8:38 PM

When can we expect good spectroscopic readings from the new planets?

Paul November 17, 2008 at 5:35 AM

Brilliant photo. We are really getting close to the time when we might actually look at another earthlike planet outside our solar system. Then the real space race will begin!

Bigboy November 17, 2008 at 12:47 PM

I’m getting a hard on!

The Occupant November 17, 2008 at 11:48 PM

* * *
Yeah. . .little too much information there, Bigboy.

Anyway, while I am not quite as enthused as some of my fellow posters, I am still delighted and impressed by this discovery.
Great work by all parties!

wh November 18, 2008 at 9:08 AM

I think I see a little blue in there. That’s right, that’s why it’s named Fomalhaut b, b stands for blue :)

Louis Morelli November 20, 2008 at 4:18 PM

About: “ Hubble Directly Observes a Planet Orbiting Another Star”

Interesting news ! Heartiest greetings to the Hubble team & NASA team.
But… the news has contradictions with known theories and it was a prediction 20 years ago from the Universal Matrix Theory. Are there wrong interpretations from Hubble’s collected data? Let’s see the following:
1) It is possible that the body is not a planet, anymore. It is brighter than the expected. It can be a very old planet going to be a pulsar;
2) The excess of dust around the star can be disposable material from an old, dying star, and not about a young star;
3) Maybe the star is not so different from the sun, about long life. The sun can reach 10 billions years. We have a lot of data from the sun. We have few data from that star. Who could authorize us to say there is star living only 1, 2 billion years? Everything is suggesting the star has the same time of life like any other star. Our models are suggesting the star is about 7 billions years old.
The Universal Matrix models ( ) suggests that old stars produces dust while its combustible is finishing, like any other fire you see at Earth. When the star become old, its planets are old also, they begin to be brighter, till becoming a pulsar. The tiny edge at the dust can be the initial formation of a new black hole, as we can see at the models.
By the way, congratulations and thanks for the good job. We work with data like that to testing our models…

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