Here’s a very interesting SETI Institute seminar by Olivier Guyon about the possibilities of directly imaging planets in the habitable zones of stars by using coronagraph techniques on telescopes to suppress the glare of the star. Could work with a Hubble size telescope in orbit or with the new giant ground based telescopes coming on line in the next decade or so such as the Giant Magellan Telescope and the European Extremely Large Telescope.
He also spoke about the citizen science program PANOPTES – “Finding exoplanets with digital cameras” – using the transit technique.
Caption:
Olivier Guyon, University of Arizona and Suburu Telescope, HI
Abstract:
Directly imaging exoplanets is both scientifically exciting but notoriously challenging. Scientifically, obtaining images of rocky planets in the habitable zones of stars is key to finding if and how life developed outside the solar system. Large-scale biological activity can modify the chemical composition of the planet’s atmosphere and its surface properties, both of which can be studied by spectrophotometry. The measurement is however extremely challenging, as the planet light is considerably fainter that the host star’s light, and the angular separation between the two objects is about 0.1 arcsecond or less.
Conventional imaging systems cannot overcome the high star to planet contrast, and unusual optics are required for imaging exoplanets. Dr. Guyon will describe such systems (coronagraphs) and the upcoming scientific opportunities associated with their deployment on ground-based telescopes and in space. He will show that ground-based extremely large telescopes (ELTs) will have the ability to directly image and spectroscopically characterize rocky planets in the habitable zones of nearby M-type stars, thus providing scientific evidence for (or against) the presence of life outside our solar system. Space telescopes operating in optical light are well suited to target Earth-like planets around Sun-like stars.
Dr. Guyon will also describe the PANOPTES (Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanet Survey) project, aimed at supporting a world-wide network of small robotic digital cameras built by citizen scientists and schools to identify a large number of transiting exoplanets.
The software OSCAAR/OSCAAR at GitHub allows for small telescopes to observe the transit of an exoplanet across the face of its home star:
The original OSCAAR team at the University of Maryland created OSCAAR because we wanted to observe transiting exoplanets at our small campus observatory, but our faculty and staff at the time had never used our observatory for such observations. We experimented with different observing and analysis techniques until we got our first transit light curve of HD 189733 b in the summer of 2011. We immediately wanted to share what we learned, and in the two years since then we’ve built OSCAAR for use by others like us — with access to basic observing equipment and a drive to observe transiting exoplanets, who need a place to start.
OSCAAR is continuously being enhanced and expanded by an open community of active observers and astronomers. Our contributors today span from NASA’s Goddard Space Flight Center to the University of Leiden, and observers getting started with OSCAAR reach from Vestal, New York to Athens, Greece. If you’re interested in using or contributing to OSCAAR, we look forward to welcoming you into the community! Don’t be shy to ask how you can get involved! Contributing to OSCAAR makes a great undergraduate research project, for example.
The new software is called the Open Source differential photometry Code for Accelerating Amateur Research, or OSCAAR for short. OSCAAR measures changes in the brightness of stars. When exoplanets pass between their stars and Earth, they reduce the amount of light that reaches Earth. OSCAAR accounts for the distortion of light that occurs in the Earth’s atmosphere and for changes in light that may occur because there are clouds overhead.
Those who use OSCAAR will likely find giant gas planets orbiting close to their stars. Hot. (Literally.) That’s because such planets are large enough to cause enough change in their stars’ light for amateur equipment to detect. Also, because they’re close to their stars, their orbits are small, swift and measurable over the course of one night.
“Recorded by all six NASA cameras in the Southeast, this fireball was one of the brightest observed by the network in 5 years of operations,” Bill Cooke, head of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Ala., wrote in a blog post Tuesday (Sept. 3).
“From Chickamauga, Georgia, the meteor was 20 times brighter than the full moon; shadows were cast on the ground as far south as Cartersville.”
Here’s a brief video of the fireball talken by a NASA camera:
Caption:
Early Wednesday morning, at 3:27:20 AM Eastern Time, a piece of an asteroid, about 2 feet in diameter and weighing over 100 pounds, entered Earth’s atmosphere above the Georgia/Tennessee border, just south of Cleveland. The meteor was moving northeast at 56,000 miles per hour, and began to break apart north east of Ocoee, at an altitude of 33 miles. A second, fragmentation occurred less than half a second later, at an altitude of 29 miles. NASA cameras lost track of the fireball pieces at an altitude of 21 miles, by which time they had slowed to a speed of 19,400 mph. Sensors on the ground recorded sound waves (“sonic booms”) from this event, and there are indications on Doppler weather radar of a rain of small meteoritic particles falling to the ground east of Cleveland, Tennessee.
The Curiosity rover continues do excellent skywatching on Mars:
This video clip shows the larger of the two moons of Mars, Phobos, passing directly in front of the sun, in an eclipse photographed by NASA’s Mars rover Curiosity.