A telescope about the size of a decent camera, operated from a tiny observatory in Sonoita, has discovered its third exoplanet.
Researchers at Kitt Peak, meanwhile, have used its largest telescope, the 4-meter Mayall, to knock a few of NASA's Kepler exoplanet candidates off the habitable list - turns out the stars they orbit are bigger and, therefore, hotter than expected and might fry any known life forms.
The separate Arizona news about exoplanets - any planet orbiting a star other than our own - was announced Tuesday at a meeting of the American Astronomical Society in Indianapolis.
New planet
The new exoplanet, KELT-6b, was detected by the Kilodegree Extremely Little Telescope project, installed in the Winer Observatory near Sonoita.
The telescope is operated by Ohio State and Vanderbilt universities. KELT, basically a digital camera with a 42 mm lens, watches large swaths of the night sky, looking for a planet signature - the periodic dimming of any of the stars in its field of view. It covers most of the Northern Hemisphere sky each year.
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"It's nothing more than a high-end digital camera," said Karen Collins, a doctoral student at the University of Louisville, in Kentucky.
Collins confirmed the discovery using slightly larger telescopes at Louisville's Moore Observatory.
KELT-6b was found in the constellation Coma Berenices, near Leo, about 700 light-years from Earth.
Mark Trueblood, Winer Observatory owner and director, provides space and maintenance for several robotic telescopes in a building near his home in Sonoita.
He said the new planet is the third one found by KELT from Sonoita - proof that big science can come from small telescopes. "It's not the size of the telescope; it's the size of the idea that counts," he said.
Kepler revisited
The Kepler study presented at the meeting was the result of three years' work, performed over 48 nights at the Mayall Telescope at Kitt Peak National Observatory by Mark Everett and David Silva of the National Optical Astronomy Observatory, and Paula Szkody of the University of Washington.
Steve Howell, who formerly worked at Kitt Peak and is now project scientist on NASA's planet-hunting Kepler mission, formed the team to follow up on his mission's discoveries. He said he was not at all disappointed to discover that some of Kepler's size estimates were off by as much as 35 percent.
"There were some hints from early on that some of the stars were a little bigger. Now we have the largest, complete sample that has all been done the same way. It's a trend," Howell said.
Not all the stars were bigger in the spectroscopic data obtained by the 4-meter Mayall, Everett said. "On average, it implied a higher temperature for these planets. It could move it up tens to hundreds of degrees (Celsius)."
Some planets formerly deemed candidates for "habitability" - having a temperature akin to those found on Earth - may no longer be in that category, he said.
Silva, the director of NOAO, said he was more intrigued by what the survey confirmed about the "metallicity" (proportion of elements other than hydrogen and helium) of the host stars. Larger planets were more likely to be orbiting stars with higher metallicity, the survey found. "That's telling us something I'll leave to the theorists," he said.
Silva said the survey, which continues with 1,500 more candidates, is a good demonstration of the mix of telescopes needed for planet discovery.
"Kepler is a discovery machine," he said, but like most NASA missions, "it then requires extensive ground-based follow-up."
Contact reporter Tom Beal at tbeal@azstarnet.com or 573-4158.
