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New Instrument Should Speed Exoplanet Hunt

Busy times. Centauri Dreams has three new Acta Astronautica papers waiting for review, but Stardust is about to return with cometary dust (and, we hope, interstellar materials), and, of course, New Horizons is just four days from liftoff. Add to that the usual flurry of news from the just concluded American Astronomical Society meeting and it’s clear I’m going to be behind the curve for a week or so just trying to catch up. Bear with me, though, because fascinating stuff keeps rolling in, such as the singular exoplanet detection below.

Newly discovered exoplanetWhat’s interesting is not just the new planet but the detection method. Normally, Doppler radial velocity measurements rely on spectographs mounted on large telescopes. A new instrument called the Exoplanet Tracker (ET) uses an interferometer instead, a device capable of more precise measurements because it can capture more light.

Image: An artist’s rendition shows a planet orbiting a very young, active star pocked with dark star spots and speckled with flares and other surface activity. A team led by a University of Florida astronomer announced Jan. 11, 2006, the discovery of the planet orbiting a star just 600 million years old, one of the youngest stars ever found with a planetary companion. Credit: P. Marenfeld and NOAO/AURA/NSF.

Far cheaper than comparable spectographs as well as lighter and smaller, the Exoplanet Tracker was used with the the special 0.9-meter Coudé feed system within the 2.1-meter telescope at Kitt Peak National Observatory near Tucson. The team, led by Jian Ge (University of Florida), thus became the first to discover a planet this distant using a telescope mirror less than 1 meter in size. Because the larger telescopes commonly used in planet hunting are in such demand, the ET opens up the prospect of accelerating our planetary detections through more readily available equipment.

“In the last two decades, astronomers have searched about 3,000 stars for new planets,” said Ge. “Our success with this new instrument shows that we will soon be able to search stars much more quickly and cheaply – perhaps as many as a couple of hundred thousand stars in the next two decades.”

Add to that the fact that the Exoplanet Tracker seems to be capable of monitoring multiple planets at the same time. In fact, a version is in the works that will be able to carry out a simultaneous survey of 100 stars. A trial planet survey will take place in the spring on the Sloan Digital Sky Survey 2.5 meter wide-field telescope at the Apache Point Observatory in New Mexico.

Centauri Dreams‘ take: Let’s not lose the planet in the shuffle. It’s another ‘hot Jupiter,’ completing its orbit in less than five days and thus closing quite close to its parent star (which is, by the way, about 100 light years away in the constellation Virgo). At least half as massive as Jupiter, the new planet is also anomalous in being part of an exceedingly young system. Our Sun, after all, is 5 billion years old; the star under discussion is a comparative infant at 600 million years.

On a broader level, notice that Ge is talking about searching several hundred thousand stars within the next two decades. Clearly, we are about to enter into an extraordinary period of planet detections. A variety of space mission options are on the table, from Kepler to SIM PlanetQuest (formerly called the Space Interferometry Mission) and Terrestrial Planet Finder, while on Earth the technologies for creating telescopes of unprecedented size and capability are evolving daily (consider, for example, the OWL instrument). Now we have the possibility of using smaller telescopes to conduct multi-star surveys for exoplanets. How soon will it be that we can speak of a genuine planetary census of all nearby stars?