Best Photo Yet of an Exoplanet

This artist’s impression shows what the planet inside the disk of Beta Pictoris may look like. Only 12 million years old, or less than three-thousandths of the age of the sun, Beta Pictoris is 75 percent more massive than our parent star. Credit: ESO/L. Calçada

While it may look like only a tiny smudge to the untrained eye, a freshly released image represents the best direct photograph ever snapped of a planet beyond our solar system.

Located some 63.5 light-years from Earth, Beta Pictoris b appears to be a Jupiter-like gas giant planet. It orbits a star similar to our own sun but much younger, at about 12 million years old (the sun has marked nearly 4.6 billion years).

A combined 30-minute GPI image depicts the planet Beta Pictoris b (bright spot) orbiting its star (center), which has been subtracted from the image. Credit: Bruce Macintosh et al.
A combined 30-minute GPI image depicts the planet Beta Pictoris b (bright spot) orbiting its star (center), which has been subtracted from the image. Credit: Bruce Macintosh et al.

Captured in a record-setting one-minute exposure, the exoplanet orbits its parent star a little closer than Saturn orbits the sun. That’s about ten times farther than Earth is from our sun.

Previous pictures—including Hubble Space Telescope images released in 2006—had revealed that a disk of dusty debris surrounds Beta Pictoris.

A gap in the disk had suggested that the gas giant planet was plowing through the debris disk and clearing an orbit for itself. But the existence of the planet wasn’t confirmed until the European Southern Observatory’s Very Large Telescope captured a first picture back in 2009.

Now, the newly launched Gemini Planet Imager (GPI) has been installed on the Gemini South telescope in Chile, creating a telescope that is at least ten times more sensitive than previous generations of instruments for directly viewing giant exoplanets. These giant planets are in orbits that would not be viewable with other methods.

The newly obtained images have allowed researchers to refine our understanding of the planet’s orbit, which now is estimated to be about 20.5 years long.

Directly imaging planets has remained extremely challenging for astronomers, simply because the host stars’ light blinds us to the tiny speck of faint light reflected off an orbiting planet. The largest planet in our solar system, Jupiter, which is 300 times larger than Earth, is a billion times fainter than our sun in reflected visible light, for example.

But astronomers are setting their sights on the easiest targets for now, young planets such as Beta Pictoris b, which can be spotted because they still radiate heat and are visible to specially outfitted telescopes that can detect them shining in near-infrared light.

By using a combination of techniques that include adaptive optics—where Earth’s atmospheric turbulence is removed—near-infrared detectors attached to one of the largest telescopes in the world, and complex image processing, astronomers have been able to gather the clearest view yet of an exoplanet.

Plans are now in place to expand the study using GPI and conduct a survey of 600 young, nearby stars beginning this year, resulting in a catalog of directly imaged planets of various ages and masses. It is expected that this survey may open up exciting opportunities to explore exoplanetary atmospheres and may help improve our current computer models of planetary formation.

If the predictions are right, GPI may lead to the discovery of a veritable treasure trove of planetary portraits, as many as 50 with masses as low as Jupiter’s.

The new Beta Pictoris b study is published in this week’s edition of the Proceedings of the National Academy of Sciences.

See for Yourself

While the exoplanet itself remains visible only at large observatories, backyard sky-watchers in the Southern Hemisphere can easily spot its parent star.

Here’s how: Face the southwest horizon after nightfall and look about halfway up the sky to locate the second-brightest star in the entire sky, yellow-colored Canopus.

Skychart showing location of Beta Pictoris in the southwestern sky after nightfall in the Southern Hemisphere. Credit: SkySafari by Simulation Curriculum
This sky chart shows the location of Beta Pictoris in the southwestern sky after nightfall in the Southern Hemisphere. Credit: SkySafari by Simulation Curriculum

Visible even from the southernmost United States, this star some 309 light-years away is best seen from locations south of the Equator.

Canopus is a convenient guidepost to finding Beta Pictoris, which is the second-brightest star in the tiny constellation Pictor, the Easel. It lies less than 6 degrees below Canopus, just a little more than the width of your three middle fingers held at arm’s length.

Follow Andrew Fazekas, the Night Sky Guy, on Twitter, Facebook, and his website.

Changing Planet

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.