CanariCam Science Team – Meeting in Madrid, 9/12

10.4 METER GRAN TELESCOPIO CANARIAS (GTC)

 

Two years into the commissioning process of the world’s largest infrared camera and telescope combination, the CanariCam Science Team met in Madrid, Spain, for two days in September to assess its progress and future plans. The meeting was held at facilities made available by the official Spanish government research agency, the Consejo Superior de Investigaciones Cientificas (CSIC).

Currently installed on the 10.4 meter Gran Telescopio Canarias (GTC) in the Canary Islands, CanariCam is a mid-infrared (MIR) camera designed to explore the areas around supermassive black holes, circumstellar disks where new planets may be forming, and brown dwarfs. When combined with the world’s largest optical-infrared telescope, CanariCam is at the cutting edge of MIR explorations.

UF Professor Telesco with CanariCam Installed on GTC

Designed by a team of scientists at the University of Florida, led by UF astronomer Charles Telesco, CanariCam has been put through its initial paces and passed with flying colors. Valuable GTC time has been allotted to the instrument. “We’ve got the instrument, and we’ve got the telescope time. Let’s do science!” Professor Telesco told the thirty assembled astronomers from around the world.

The University of Florida is a 5% partner in the GTC. UF is a world leader in astronomical instrumentation, and by partnering with the GTC and for having built CanariCam, UF’s Astronomy Department obtains valuable observation time to conduct its own research.

CanariCam was installed on the GTC in 2010, and has been undergoing rigorous commissioning procedures. Many aspects of CanariCam’s capabilities have been commissioned, but the marriage of CanariCam to the GTC is a work in progress, with several current issues still being ironed out. For example, strong winds (called “Calima”) in the nearby Sahara lift fine sand particles into the air and blow them across the Atlantic. Infrared imaging demands extremely clean mirrors, creating the necessity of regularly cleaning the 10.4 meter telescope, comprised of 36 separate mirrors working as one. The GTC staff astronomers present at the Madrid meeting discussed new cleaning techniques and timing to address this issue. Improving the fast guiding capabilities of the GTC is also an area where new improvements are forthcoming.

CanariCam Being Installed At Naysmyth Focus of GTC

So, what new science can we expect from CanariCam now that it has started to accumulate astrophysical data? One of its new capabilities is in the area of polarimetry, the measurement of polarization in the infrared wavelengths reaching the camera. CanariCam is the first dual-beam MIR polarimeter available at such a large telescope for astrophysical research. This mode of the camera is nearly fully commissioned.

The light from astronomical sources can become polarized (where the light “waves” become oriented in specific directions) for several reasons. For example, polarization can occur from light emitted by warm dust particles oriented like compass needles by strong magnetic fields near a star or other heating source, or by scattering of IR radiation by dust particles in disks surrounding a star. By examining the orientation and change in polarization with wavelength, astronomers can extract new information about the actual structure of distant objects. As Chris Wright, an Australian member of the team said, “Without polarization, half the information that a photon can potentially provide is thrown away.” What role do magnetic fields play in regulating star formation? Polarimetry can not only answer such questions, but also peer through obscuring layers to observe the dust near stars. CanariCam polarimetry is working as promised so far, and according to Chris Wright “opens up whole new areas for study.”

In order for the scientific community at large to use CanariCam on the GTC, it will be necessary to provide “pipelines” of software that will give astronomers the tools needed to reduce and analyze the data obtained. Dan Li, a graduate student from UF, and Omaira Gonzalez Martin, a scientist with the Institute for Astrophysics in the Canary Islands (IAC), each described the interfaces they had developed to reduce imaging and spectrographic data from CanariCam. The assembled scientists discussed ways, including development of such “pipelines,” to encourage involvement from the astrophysical community.

Chris Packham, one of the designers of CanariCam, described some preliminary polarimetry results, examining Cygnus A, an Active Galactic Nucleus (AGN) thought to be a supermassive black hole about 600 million light years from us. It was the faintest object CC has looked at so far, and showed some unusual polarization. Packham emphasized that much more data is needed before drawing any conclusions, and several of the scientists present at the meeting suggested ways of eliminating certain types of observational errors or biases in the results.

As the only non-professional present at the meeting, I was struck by the way in which real science is not someone shouting “Eureka! Look what I found!” Instead, it is a constant process of looking for errors, testing and retesting conclusions, attempting to falsify the data in as many ways as possible.

CCST Attendees in Madrid

Team member and prominent astrophysicist Rafael Rebolo of the IAC summarized the current status of CanariCam for the assembled team. “CanariCam meets the design requirements.” As further commissioning moves forward, he urged the team to help streamline the process of data reduction in order to encourage greater involvement from the astrophysical community. As current team projects begin to acquire science, data and results, “we can show what a breakthrough CanariCam is.” He suggested preliminarily planning a community-wide meeting some time in late 2013 or 2014, to highlight to the astrophysical community what CanariCam is doing, and what it can do.

As Professor Telesco said at the beginning of the two day meeting, “Let’s do science!”

Observing the Venus Transit

On Tuesday June 5th, 2012 the planet Venus will transit across the disk of the Sun. That means that Venus will pass exactly between Earth and the Sun, appearing for us as a dark spot traversing the face of the Sun.

The University of Florida Astronomy Department will setup telescopes specially provided with a safe solar filter to observe this rare sight, which will not happen again until the year 2117, 105 years from now. Don’t miss it!

The event will be visible from Gainesville from 6:04 PM until sunset. UF telescopes will be set up on the east end of the UF band shell field or FLAVET field on the UF campus, off Museum Road.

 
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This event is free and open to the public.

Please remember that viewing the transit involves looking at the Sun and requires special eye protection. Never look at the Sun without protection because severe eye damage may occur, even if you don’t feel any discomfort. Do not try to observe the Sun with the naked eye or with any optical device such as binoculars or telescopes unless they are properly fitted with a special solar filter.

In Eighteenth and Nineteenth centuries, Transits of Venus allowed astronomers to first calculate the distance to the Sun. Today astronomers use transits to find planets orbiting stars other than the Sun, which are called exoplanets. They do it by measuring the dips in brightness of these stars that happen when the exoplanets cross in front of them, for example with NASA’s Kepler Mission.

Check out http://www.astro.ufl.edu/public/jun.html for updated information.

You can also check this websites to learn more about the 2012 Transit of Venus:

http://eclipse.gsfc.nasa.gov/OH/transit12.html

http://www.transitofvenus.org/

Or watch the 4 minutes video summary at www.transitofvenus.org

“Hot Jupiters” are lonely

63 Hot Jupiter Canridates. CREDIT: Fermilab Center for Particle Astrophysics

A group of scientist including UF astronomy professor Eric Ford has recently conducted a search for planets around stars already known to host “hot Jupiter” type planets, showing that these bodies are most likely to be alone in their systems.

“Hot Jupiters” are giant planets beyond our solar system, roughly the size of Jupiter orbiting very close to their parent stars and thus much hotter than the Earth or Jupiter (hence the name). They have very short orbital periods, completing a turn around their stars in less than 10 days. This study provides new insights into how they are formed.

The data used was gathered by NASA’s planet-hunter Kepler mission, which uses a 1-meter space telescope to stare constantly at a patch of the Milky Way, registering the small decreases in the light from stars caused when a planet crosses in front of it.

Scientists dug into Kepler’s data and selected a sample of 63 planetary systems containing previously detected hot Jupiter candidates. Then they looked for signals of additional planets either crossing in front of the host stars or gravitationally tugging on the hot Jupiter’s orbit. In all cases they found no evidence of additional planets. To allow comparisons, they used the same methods to study a sample of “warm Jupiter” candidates, equally big planets but located farther away from their parent stars and “hot Neptunes,” smaller but closer to the stars. They found compelling evidence that at least 10 percent of the warm Jupiters and one third of the hot Neptunes have other planetary companions nearby in the system. Thus, why are all the hot Jupiters so lonely?

Astronomers believe it results from the way the hot Jupiters are formed, now thought to be different from most other planets. Current models suggest that they are probably formed farther away from their host star, and then gravitational interactions with another body cause their orbits to become highly elongated. Each orbit the hot Jupiter passes very close to the host star and then travels far away. The star raises tides on the planet, repeatedly stretching it and causing its orbit to become smaller and more circular. This process would remove or destroy other low-mass planets that originally formed between the star and the giant planet.

“We looked for companion planets near hot Jupiters in order to learn a bit more about their formation,” Ford said. “The lack of nearby planets supports the theory that a close encounter with another body in the system caused the elongation of the orbit. When a giant planet repeatedly passes through the inner regions of a planetary system on an elongated orbit, it would wreak great havoc on any planets that had formed there. The other planets would either fall into the star, collide with the hot Jupiter or be kicked out of the system via a gravitational slingshot.”

In 1995 the first planet orbiting a sun-like star was discovered. It and most exoplanets found in the early days of the exoplanet search happened to be hot Jupiters.

“That was because they are easier to find than smaller planets or others more distant to their host star,” Ford said. “Now, we know that less than 1 percent of stars harbor hot Jupiters, so they are relatively rare. A special sequence of events like strong gravitational interactions between two giant planets followed by tidal circularization seems to be the most plausible scenario for the formation of hot Jupiters.”

The research was led by Jason Steffen from the Fermilab Center for Particle Astrophisics.

NASA’s Kepler Mission, operating since 2009, is revolutionizing the field of planetary science. For the first time it is enabling astronomers to conduct this kind of detailed population studies of planet candidates. By allowing astronomers to study systems other than our own, they are able to confront planet formation theories with observational data, giving important insights into the range of contemporary planetary system architectures and the possible existence of habitable planets within them.

Link to UF news http://news.ufl.edu/2012/05/07/hot-jupiters/

UF participates in nation’s largest science and technology festival

2010 Edition UF's participants, in front of their booth 

 

The University of Florida’s departments of astronomy, mechanical and aerospace engineering, and the Institute of Food & Agricultural Sciences will participate in the USA Science & Engineering Festival in Washington, D.C., Saturday and Sunday.

The theme of the UF booth is “Gators in Space,” where displays and interactive activities will be used to explain how astronomy and engineering allow a better understanding of the universe and life on Earth.

At the UF booth, Expo visitors will have the opportunity to build their own working telescopes, experience the physical principles needed to control a spacecraft, and handle samples of simulated Lunar and Martian regolith (planetary “soil”) and the palm-sized plant system launched to the International Space Station.

Static and dynamic displays will show how the university is using cutting-edge science and technology to provide solutions to challenges that the world is facing. The booth will have displays of the hardware used for the exploration of space: SwampSat, the first 4-inch-cubed satellite designed and built at UF; a scale model of the Gran Telescopio Canarias, the world’s largest telescope, used by UF astronomers for their research; an orbital plant growth facility and a clinostat (ground-based hardware used to disrupt the effect of gravity sensing in biology). Students and researchers will be available to demonstrate and discuss each of these items.

The USA Science & Engineering Festival is the country’s only national science festival. Its aim is to increase the public’s awareness of the importance of science and to encourage youths to pursue careers in science and engineering. The fair is a month-long celebration, culminating in a two-day exposition including 100 live performances and 3,000 different hands-on activities by more than 500 of the nation’s leading science and engineering organizations. It is free and open to the public.

“The previous Expo held in October of 2010 was a celebration of science; we had many visitors attending the UF booth, including a number of UF alumni. They were very impressed with the kinds of science and engineering projects that were coming out of their alma mater,” said Ata Sarajedini, professor of astronomy who is the overall coordinator of the UF group.

“We have created an official twitter @GatorsinSpace so people can follow all of our activities,” said Dante Buckley, a participating UF engineering doctoral student who is also a member of professor Norman Fitz-Coy’s SwampSat team.

Eric Schultz, an IFAS doctoral student in the space biology program of Robert Ferl and Anna-Lisa Paul, is excited about the opportunity to show visitors advances in biological research in space, “This is a great opportunity to promote interest in the biological sciences and to educate the public about the benefits of astrobiology and extraterrestrial research in general,” Schultz said.

The following video was aired by the local news, before last expo's edition.

The participation of UF at this festival has been made possible by the UF provost’s office, department of astronomy, Florida Space Grant Consortium, the College of Liberal Arts and Sciences, the College of Engineering, the College of Agricultural and Life Sciences and Institute of Food and Agricultural Sciences and the Office of Admissions.

UF-led team use new observatory to characterize low-mass planets orbiting a nearby star

Published in University of Florida News on Thursday, April 9, 2012.

The narrow dust ring around Fomalhaut. Yellow at top is the ALMA image, and the blue at bottom is Hubble Space Telescope image. The star is at the location of the bright emission at the center of the ring.

CREDIT: A.C. Boley (University of Florida, Sagan Fellow), M.J. Payne, E.B. Ford, M. Shabran (UF), S. Corder (North American ALMA Science Center, NRAO), and W. Dent (ALMA, Chile), NRAO/AUI/NSF; NASA, ESA, P. Kalas, J. Graham, E. Chiang, E. Kite (UC, Berkeley), M. Clampin (NASA Goddard Space Flight Center), M. Fitzgerald (Lawrence Livermore National Laboratory), and K. Stapelfeldt and J. Krist (NASA Jet Propulsion Laboratory).

University of Florida astronomers have found compelling evidence for two low-mass planets orbiting the nearby star Fomalhaut, just 25 light years from Earth.

Twice as massive as the sun and 20 times brighter, Fomalhaut is surrounded by a ring of dust and debris, making it a favorite system for astronomers to study and a natural laboratory for testing planet formation theories.

In 2008, images of Fomalhaut taken by the Hubble Space Telescope led to the discovery of “Fomalhaut b,” the first extrasolar planet to be directly detected in visible light. At the time, astronomers believed it to be a giant planet, akin to Jupiter or Saturn, but later infrared images failed to detect the planet, meaning that it had to be smaller than Saturn.

UF astronomers, along with scientists from the new Atacama Large Millimeter Array in Chile, known as ALMA, and the National Radio Astronomy Observatory, used ALMA’s superior resolution and sensitivity to study the system in unprecedented detail. Their results indicate that there are not one, but two planets, with masses between that of Mars and a few times larger than Earth, working together to shape the ring of dust.

The new study reveals that the ring is sharply truncated in the inner and outer edges and is only about 16 astronomical units, or AU, wide, or about 16 times the distance between the Earth and the sun. That may seem large, but the center of the ring is about 140 AU, making the ring relatively very narrow. It also finds that the ring is vertically thin, about one-seventh as tall as it is wide. Those properties give important clues to explain the planetary system of Fomalhaut.

The results are described in a paper to appear this month in the Astrophysical Journal Letters.

“Combining ALMA observations of the ring’s shape with computer models, we can place very tight limits on the mass and orbit of any planet near the ring.” said Aaron Boley, a Sagan Postdoctoral Fellow at UF and leader of the study. “The masses of the planets must be small so they do not destroy the ring, but their masses cannot be too low or they would not shape the ring.”

Although Fomalhaut is a much hotter star than the sun, the planets are so far from their host star that they are among the coldest planets known around a normal star. They are thought to be low-mass bodies, but astronomers do not have enough data to tell whether they have a significant amount of hydrogen gas or are mostly rock and ice.

“ALMA observations show that Fomalhaut’s ring is even more narrow and thinner than previously known,” said Matthew Payne, an astronomer at the University of Florida who contributed to the study. “Fomalhaut b alone only explains the ring's sharp inner edge. Our analysis suggests that two planets, one interior and one exterior, are shepherding the ring, analogous to how Uranus’ moons Cordelia and Ophelia confine Uranus’ brightest ring.”

Credit: ALMA (ESO/NAOJ/NRAO). Visible light image: the NASA/ESA Hubble Space Telescope A. Fujii/Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble). Music: John Dyson (from the album Moonwind).

The Atacama Large Millimeter/submillimeter Array, located in the Atacama desert of northern Chile at an altitude of 16,400 feet is the largest astronomical project in existence. Still under construction, ALMA began scientific operations in September.

“ALMA may still be under construction, but it has already proved to be the world’s most powerful telescope for observing the universe at millimeter and submillimeter wavelengths of light.” said Stuartt Corder, an astronomer at the National Radio Astronomy Observatory and co-author of the study.

“Once ALMA is completed, we will be able to study systems like Fomalhaut with even greater detail, and see through the veil of dust that hides the early stages of planet formation,” said co-author Bill Dent, an astronomer at ALMA.

This research was supported by the NASA Sagan Fellowship Program, the National Radio Astronomy Student Observing Support Program and the University of Florida's College of Liberal Arts and Sciences. The Joint ALMA Observatory is a partnership of the European Organization for Astronomical Research in the Southern Hemisphere, the National Astronomical Observatory of Japan (on behalf of the National Institutes of Natural Sciences and Academia Sinica), and the NRAO (managed by Associated Universities, Inc. on behalf of the NSF and the National Research Council of Canada) in cooperation with the Republic of Chile.

Professor Eric Ford TEDxUF talk

TEDxUF talk by UF Astronomy Professor Eric Ford is available online, for those who missed it and for those who want to enjoy it again.

CanariCam is ready for science!

CanariCam, the infrared instrument onboard the world’s biggest optical-infrared telescope is officially ready for scientific research.

The instrument was built in UF by a team of astronomers and engineers led by astronomy professor Charles Telesco. Basically, it's a high-tech, heat-sensitive camera that will allow researchers to look for planets outside our own solar system and better explore hidden black holes at the centers of galaxies, among other tasks.

The Great Telescope CANARIAS, also known as GTC is the biggest optical-infrared telescope in the world, with a primary mirror of 10.4 meters (34.12 feet). The unique specifications of CanariCam, combined with this mighty telescope, form a cutting-edge scientific tool.

University of Florida is a 5% partner in the GTC, in operation since 2009. UF is developing and using instruments such as CanariCam to maximize the telescope’s scientific productivity for all the scientific community. In return, the University of Florida gets observation time for its own projects.

CanariCam capabilities include high-resolution imaging, spectrography, coronography and polarimetry. The latter is an exclusive feature in 8 to 10 meter class telescopes. This is a unique combination in a single instrument, according to professor Telesco.

“With this instrument, the GTC will allow projects impossible to do with other smaller telescopes and will be in the forefront of infrared astronomy for a very long time.” Telesco said.

Some bodies or regions of the universe emit infrared radiation, or heat, which is detected by CanariCam. This capability will spearhead research exploring planets outside our solar system and regions where planets and stars are forming. Also, the fact that infrared radiation can pierce easily cosmic dust clouds means that CanariCam would be able to see objects that are totally obscured at visible wavelengths.

UF Astronomy Professor, quoted in National Geographic

Astronomy Professor Eric Ford was quoted in National Geographic, last February 24th.

You can read it following this link: http://goo.gl/LNhj7

Reflections on Kepler's 3rd birthday



Artist's rendition of Kepler spacecraft. Credit: NASA/Kepler mission/Wendy Stenzel

Three years ago, I witnessed the launch of NASA's Kepler mission. As the first space mission designed from the ground-up to study exoplanets, it was a major juncture in the search for other worlds and all of astronomy. Yet, the launch was really one more opportunity to practice patience. As a part of the Kepler Science Team, I waited to learn of the spacecraft's health, then the pointing and focus, then the data quality, then enough data to begin to do science, then the first planet candidates, then the progress of our colleagues in improved data analysis techniques. Now, we wait for Kepler to observe long enough to find Earth-size planets in the habitable zones of solar-like stars.

As a member of the transiting timing variations working group, I'm also anxiously waiting for enough data to measure the masses of small planets, so we can map the transition between "super-Earth's" and "mini-Neptunes". These new classes of planets for which there is no analog in our solar system are actually quite common for other stars. Why doesn't our own solar system have any super-Earths (or mini-Neptunes)? How did Earth resist Icarus's urge to fly too close too the Sun for life, like most of the thousands of planets being discovered by Kepler? Is there something special about our solar system? Continued observations and analysis of the Kepler data provide best chance to address questions like these.

At the launch, several mission's founders were already a tight nit team. Over the last three years, I and my small research group at UF have become part of the Kepler family. I can't guess how many emails, telecons, heated debates we've had. Those have pushed us to work many late nights to search for planets, to vet planet candidates, to optimize the next quarter's target list, to provide some analysis in time for another team member's paper, to explain why NASA should keep the mission alive beyond 2012, and to convey results and the sense of wonder to the public. It's been an exhausting, but exhilarating ride. I hope we can hang on for a few more years.

Prof. Ford during the Kepler launch, 2009. Credit: NASA/Kepler Mission.

Kepler has opened our eyes to the power of time-domain astronomy, providing nearly-continuous, long-term and ultra-high precision photometry. The only analogy I can offer is to how much we learned about the universe when previous NASA missions made it possible to see the sky in wavelengths previously inaccessible due to Earth's atmosphere hanging over telescopes on the ground. Far above Earth's atmosphere, Kepler's data quality is so much better than anything before it that most astronomers are just beginning to appreciate the possibilities for studying planets and stars in ways never before possible. Kepler has already returned a treasure trove of data, one that will be mined by astronomers for many years if not decades into the future.

Kepler was always intended to be a stepping stone towards future missions that could study the atmospheres and surfaces of potentially Earth-like planets. I hope that humans will muster another great observatory optimized for exoplanet science, so we can realize those goals during my career, or at least my lifetime. If not, at least we have the Kepler Mission.

Professor Eric B. Ford.

Kepler Mission facebook page

Call for applications for IScAI 2012

IScAI Students visit the Gran Telescopio Canarias
 (Photo: Consolider-GTC)

The Instituto de Astrofísica de Canarias (IAC) and partner institutions announce the 2012 edition of the International School for Advanced Instrumentation or IScAI, an international collaboration between universities, research centers and technologic companies with the goal of offering astronomers, physicists and engineers specialised formation in all areas related with the designs and building of cutting-edge scientific instrumentation.

The programme consists of five weeks of intensive course work on five different subjects related to the design and construction of astronomical instrumentation. Each one imparted by top professors on its field: in optics, Steve Eikenberry from University of Florida; in mechanics, Manuel Maldonado (FRACTAL S.L.N.E); in software, Nicolas Carfiel (Universidad Complutense de Madrid); in electronics, Enrique Joven (IAC); and in management Marisa García Vargas (FRACTAL S.L.N.E).

After the theoretical lessons, students can opt to a hands-on period in institutions or companies related to the school, working in world-class instrumentation programs.

These will be held at the headquarters of the Instituto de Astrofísica de Canarias, in La Laguna, on the island of Tenerife in Spain's Canary Islands. The IScAI will start in May 2012 and is open to astronomers, physicists and engineers worldwide. The deadline for applications is March 1, 2012.

IScAI founding institutions are Instituto de Astrofísica de Canarias (Spain), University of Florida (USA), Universidad Complutense de Madrid (Spain), Instituto Nacional de Astrofísica, Óptica y Electrónica de México (Mexico) and Universidad Nacional Autónoma de México (Mexico). Other institutions have joined like Isaac Newton Group of Telescopes, and Centro de Astrobiología (Spain). Also the companies EADS Astrium Crisa, Fractal SLNE, GMV, IDOM, LIDAX, y NTE-Sener.

The IScAI 2012 is funded by the grant "First Science with the GTC", under the Consolider-Ingenio 2010 Programme of the Spanish Ministry of Science and Innovation.

For more information about the IScAI and the registration procedure, please check the school’s web site at: http://iscai.iac.es

UF astronomers contribute to NASA’s planet discoveries

Published on University of Florida News on Thursday, January 26, 2012.

GAINESVILLE, Fla. — NASA announced today the discovery of 11 new “solar systems” hosting at least 26 planets found with data from NASA’s Kepler Mission.

Kepler's Planetary Systems, Jan. 2012 Multiple planet systems discovered by NASA's Kepler mission. Newly found planets are shown here in green. The eight planets of the solar system are shown in blue. Credit: NASA Ames/Jason Steffen, Fermilab Center for Particle Astrophysics

The discovery nearly doubles the number of verified Kepler planets so far. It also triples the number of stars known to have more than one planet that transits – or passes in front of — its host star. Such systems are particularly valuable for the clues they provide about how planets form.

Eric B. Ford, associate professor of the astronomy department at the University of Florida, is part of the Kepler Mission science team. Ford’s research group at UF, including graduate student Robert Morehead and postdoctoral associate Althea Moorhead, has contributed to several previous Kepler discoveries. Ford is lead author of the paper describing Kepler-23 and Kepler-24, two of the 11 systems announced today.

In this research, Ford and his team not only describe the two new planetary systems but also develop a new technique that, in Ford’s words “dramatically accelerates planet discovery and will enable astronomers to confirm planets transiting fainter and more distant stars.”

The Kepler Mission uses a 1-meter space telescope to stare constantly at a patch of the Milky Way, registering the small decreases in the light from stars caused when a planet crosses in front of it. With this tool, astronomers are able to constantly monitor more than 160,000 stars at a time.

Until now, confirming that small decreases in a star’s brightness was caused by a planet required additional observations and time-consuming analysis. The new technique takes advantage of the gravitational effects that different planets in a system have on each other’s orbits. By precisely timing the deviations from the expected orbital times caused by this effect, the team was able to detect the gravitational tug exerted by the planets on each other, and confirm 10 of the newly announced planetary systems.

Five of the new planetary systems contain a pair of planets where the inner planet orbits the star twice during each orbit of the outer planet. Another five systems contain a pair of planets where the outer planet circles the star twice for every three times the inner planet orbits its star.

“These configurations help to amplify the gravitational interactions between the planets, similar to how my sons kick their legs on a swing at the right time to go higher,” said Jason Steffen, the Brinson Postdoctoral Fellow at Fermilab Center for Astroparticle Physics and lead author of a paper confirming four of the systems.

The new planets orbit close to their host stars, their size ranging from 1.7 times the radius of Earth to about the size of Jupiter. Fifteen of them are smaller than Neptune and further observations will be required to determine which of them are rocky like Earth and which have thick gaseous atmospheres like Neptune. The confirmed planets orbit their host star once every 6 to 143 days, so all of them are closer to their host star than Venus is to the sun.

The new discoveries will be published in the Astrophysical Journal and the Monthly Notices of the Royal Astronomical Society. Searching for exoplanets using real Kepler data is open to everyone by visiting planethunters.org. For more information about the Kepler mission visit: http://www.nasa.gov/kepler.

NASA‘s Kepler mission and UF astronomer find two new planets orbiting double suns

Published on UF News, January 11th 2012.

Using data from NASA’s Kepler mission, a team that includes a University of Florida astronomer has discovered two new planets orbiting double star systems, something that had never been seen until last September.

The newly confirmed planets, called Kepler-34b and Kepler-35b, will be announced in Wednesday’s online edition of the journal Nature, said Eric B. Ford, UF associate professor of astronomy. William F. Welsh, associate professor at San Diego State University, is the lead author on the paper.

An artist's rendition of the Kepler-35 planetary system, in which a Saturn-size planet orbits a pair of stars.
Image credit: Lynette Cook / extrasolar.spaceart.org

Kepler-34b and Kepler-35b both orbit a “binary star.” They are actually a pair of gravitationally bound stars that orbit each other. While the existence of such bodies, called “circumbinary planets,” had long been predicted, they remained just a theory until the team discovered Kepler-16b in September 2011. They dubbed Kepler-16b “Tatooine” because of its resemblance to the two-sun world depicted in the “Star Wars” film series.

“We have long believed these kinds of planets to be possible, but they have been very difficult to detect for various technical reasons,” Ford said. “With the discoveries of Kepler-16b, 34b and 35b, the Kepler mission has shown that the galaxy abounds with millions of planets orbiting two stars.”

The planets were discovered by measuring the star light decrease as the planets pass in front of, or transit, either of the two stars. Kepler also measures the star light decrease when one of the stars passes in front of the other. The mutual gravitational tugs of the stars and planets cause the times of the transits to deviate from a regular schedule, allowing astronomers to confirm the planet and measure its mass.

Both planets are low-density gas giants, comparable in size to Jupiter, but much less massive. Compared to Jupiter, Kepler-34 is about 24 percent smaller in size, but has 78 percent less mass. It can complete a full orbit in 288 terrestrial days. Kepler-35 is about 26 percent smaller, has 88 percent less mass, and completes its orbit around the stars much faster – just 131 days.

The astronomers believe the planets are made primarily of hydrogen and too hot to sustain life.

“Circumbinary planets can have much more complex climates, since the distance between the planet and each star change significantly during each orbital period, the length of an alien planet’s year,” Ford said. “For Kepler-35b, the amount of incoming star light changes by over 50 percent within a single Earth year. For Kepler-34b, each Earth-year brings ‘summers’ with 2.3 times as much star light as winters. Over the course of a year, the change in the amount of sunlight heating the Earth varies by only 6 percent.”

NASA’s Kepler mission, which began in March 2009, uses a 1-meter space telescope trained on one small portion of the Milky Way for several years. Astronomers analyze data from the telescope for periodic dimming that indicates a planet crossing in front of its host star. The mission’s goal is to find the frequency of Earth-size planets in the habitable zone of their host stars – where a planet might have liquid water on its surface.

Most Sun-like stars in the galaxy are not alone, like the Earth’s sun, but have a “dance partner,” forming a binary system or binary star. Kepler has already identified about 2,165 eclipsing binaries, of the more than 160,000 stars being observed.

NASA originally planned to stop receiving data from the Kepler spacecraft in November 2012.

“Astronomers are practically begging NASA to extend the Kepler mission until 2016, so it can characterize the masses and orbits of Earth-size planets in the habitable zone. Kepler is revolutionizing so many fields, not just planetary science,” Ford said. “It would be a shame not to maximize the scientific return of this great observatory. Hopefully common sense will prevail and the mission will continue.”

The public can contribute to searching for planets using real Kepler data by visiting planethunters.org, which works with the latest versión of Internet Explorer, Chrome and Firefox. For additional information, downloadable slides, and full resolution versions of artwork after the embargo lifts, please see http://sdsu.edu/kepler. For more information about the Kepler mission, visit: http://www.nasa.gov/kepler.

Follow this link to see the original UF press release.