European Association for Astronomy Education

Source: NASA

NASA is marking two milestones in the search for planets like Earth; the successful completion of the Kepler Space Telescope's 3 1/2- year prime mission and the beginning of an extended mission that could last as long as four years.

Scientists have used Kepler data to identify more than 2,300 planet candidates and confirm more than 100 planets. Kepler is teaching us the galaxy is teeming with planetary systems and planets are prolific, and giving us hints that nature makes small planets efficiently.

So far, hundreds of Earth-size planet candidates have been found as well as candidates that orbit in the habitable zone, the region in a planetary system where liquid water might exist on the surface of a  planet. None of the candidates is exactly like Earth. With the completion of the prime mission, Kepler now has collected enough data to begin finding true sun-Earth analogs -- Earth-size planets with a one-year orbit around stars similar to the sun. (read more)

Source: NASA Science Casts
 
 

Once, astronomers thought planets couldn't form around binary stars. Now Kepler has found a whole system of planets orbiting a double star. This finding shows that planetary systems are weirder and more abundant than previously thought.

Source: NASA Kepler

Artist's impression of planet formation.
Image credits: Credit: University of Copenhagen/Lars Buchhave .

The formation of small worlds like Earth previously was thought to occur mostly around stars rich in heavy elements such as iron and silicon. However, new ground-based observations, combined with data collected by NASA's Kepler space telescope, shows small planets form around stars with a wide range of heavy element content and suggests they may be widespread in our galaxy.(read more)

Source: NASA Kepler

Kepler's Planetary Systems' Orbits.
Image credits: NASA Ames/Dan Fabrycky,
University of California, Santa Cruz

NASA's Kepler mission has discovered 11 new planetary systems hosting 26 confirmed planets. These discoveries nearly double the number of verified planets and triple the number of stars known to have more than one planet that transits, or passes in front of, the star. Such systems will help astronomers better understand how planets form.

The planets orbit close to their host stars and range in size from 1.5 times the radius of Earth to larger than Jupiter. Fifteen are between Earth and Neptune in size. Further observations will be required to determine which are rocky like  Earth and which have thick gaseous atmospheres like Neptune. The planets orbit their host star once every six to 143  days. All are closer to their host star than Venus is to our sun. (learn more)

Source: NASA News

Artist's impression of the mini planetary system.
Image credit: NASA/JPL-Caltech

Astronomers using data from NASA's Kepler mission have discovered the three smallest planets yet detected orbiting a star beyond our sun. The planets orbit a single star, called KOI-961, and are 0.78, 0.73 and 0.57 times the radius of Earth. The smallest is about the size of Mars.

All three planets are thought to be rocky like Earth, but orbit close to their star. That makes them too hot to be in the habitable zone, which is the region where liquid water could exist. Of the more than 700 planets confirmed to orbit other stars - called exoplanets - only a handful are known to be rocky. (read more)

Source: NASA

Artist's conception of Kepler-22b. Image credit: NASA/Ames/JPL-Caltech.

NASA's Kepler mission has confirmed its first planet in the "habitable zone," the region where liquid water could exist on a planet's surface. Kepler also has discovered more than 1,000 new planet candidates, nearly doubling its  previously known count. Ten of these candidates are near-Earth-size and orbit in the habitable zone of their host star. Candidates require follow-up observations to verify they are actual planets.

The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.

Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars. (read more)

Source: Planet Hunters

Thanks to all collaborators hard work at planethunters.org - a first paper was submitted to an astronomical journal, and it is now nearly through the referee process. The findings can be seen in detail in the paper titled "Planet Hunters: Two Planet Candidates Discovered by the Public using the Kepler Public Archive Data" which you can read at: http://arxiv.org/abs/1109.4621

After careful analysis and follow-up observations with the Keck telescope in Hawaii, the Planet Hunters team sent the top 10 candidates found from your classifications of the Quarter 1 data to the Kepler team. With their help, it has been determined that two of the ten met their criteria for being classified as planet candidates.

If you're lucky enough to be one of the people who marked a transit, then your name is in the paper - the rest of you will find yourselves on the extended author list at http://planethunters.org/authors.

In other news, the Kepler team announced (http://www.nasa.gov/mission_pages/kepler/news/keplerm-Q3release.html) that the next public release of data has been moved up from June 2012 to right now. Quarter 3 is an extra 90 days of light curves, nearly doubling the time baseline we have available for all the Kepler stars - meaning you can find even longer period planets hidden in the data. We're already working on getting this data to you, but in the mean time, there’s still lots of Quarter 2 data left to search through.

Planet Hunters is already producing fantastic results, and there is no doubt that with each new round of data, there will be more discoveries to come. Come and help the hunt for planets today: http://www.planethunters.org

Source: NASA-Kepler Press Release

Artist's concept of Kepler-16b. Image credits: NASA/JPL-Caltech/T. Pyle.

The existence of a world with a double sunset, as portrayed in the film Star Wars more than 30 years ago, is now a scientific fact. NASA's Kepler mission has made the first unambiguous detection of a circumbinary planet - a planet orbiting two stars - 200 light-years from Earth.

Unlike Star Wars' Tatooine, the planet is cold, gaseous and not thought to harbor life, but its discovery demonstrates the diversity of planets in our galaxy. Previous research has hinted at the existence of circumbinary planets, but clear confirmation proved elusive. Kepler detected such a planet, known as Kepler-16b, by observing transits, where the brightness of a parent star dims from the planet crossing in front of it. (read source)

Source: Kepler@NASA

Artist's conception of Kepler-10 Stellar Family Portrait.
Image credit: NASA/Ames/JPL-Caltech.

Today Kepler team is announcing another member of the Kepler-10 family, called Kepler-10c (larger foreground object in the image on this page). It has a radius of 2.2 times that of Earth's, and it orbits the star every 45 days. Both Kepler-10b and 10c would be blistering hot worlds.

The Kepler-10 system is located about 560 light-years away near the Cygnus and Lyra constellations. Kepler has discovered two planets around this star. Kepler-10b is, to date, the smallest known rocky exoplanet, or planet outside our solar system (dark spot against yellow sun). This planet, which has a radius of 1.4 times that of Earth's, whips around its star every .8 days. Its discovery was announced in Jan. 2011. (read more)

Source: Kepler@NASA

Kepler's discoveries. Image credit: NASA/Wendy Stenzel.

NASA’s Kepler spacecraft is proving itself to be a prolific planet hunter. Within just the first four months of data, astronomers have found evidence for more than 1,200 planetary candidates. Of those, 408 reside in systems containing two or more planets, and most of those look very different than our solar system.

In particular, the Kepler systems with multiple planets are much flatter than our solar system. They have to be for Kepler to spot them. Kepler watches for a planet to cross in front of its star, blocking a tiny fraction of the star’s light. By measuring how much the star dims during such a transit, astronomers can calculate the planet’s size, and by observing the time between successive events they can derive the orbital period – how long it takes the planet to revolve around its star.

To see a transit, the planet’s orbit must be edge-on to our line of sight. To see multiple transiting planets, they all must be edge-on (or nearly so).(read more)

Source: Kepler@NASA

NGC6811. Image credit: Anthony Ayiomamitis.

For many movie stars, their age is a well-kept secret. In space, the same is true of the actual stars. Like our Sun, most stars look almost the same for most of their lives. So how can we tell if a star is one billion or 10 billion years old? Astronomers may have found a solution – measuring the star’s spin.(read more)

Source: Kepler Mission

Artist's rendering comparing the size and color of the stars in the triple-eclipsing system HD 181068.
Image credit: NASA/KASC

We are entering a golden era for "stellar physics" – a term coined to describe research about the formation, evolution, interior and the atmospheres of stars. Thanks to a partnership forged among stellar astrophysics, scientists and NASA’s Kepler Mission, a goldmine of data is now available to support the world's efforts to detect planets in the habitable zone around other stars.(read more)

Source: YouTube /dfabrycky's Channel

The video above presents all the multiple-planet systems discovered by Kepler as of 2/2/2011; orbits go through the entire mission (3.5 years). Hot colors to Cool colors (Red to yellow to green to cyan to blue to gray) are Big planets to Smaller planets, relative to the other planets in the system.

In this video the author presents all the multiple-planet systems discovered by Kepler as of 2/2/2011 that have orbits that go through quarters Q0-Q2. Hot colors to Cool colors (Red to yellow to green to cyan to blue to gray) are Big planets to Smaller planets, relative to the other planets in the system.

Source: NASA Kepler

Kepler's planet candidates by size.
Image credit: NASA/Wendy Stenzel

NASA's Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet's surface. Five of the potential planets are near Earth-size and orbit in the habitable zone of smaller, cooler stars than our sun.(read more)

Source: NASA News Release 11-007
by Trent J. Perrotto and Rachel Hoover

Artist concept of Kepler 10b. Credit: NASA.

NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.

The discovery of this so-called exoplanet is based on more than eight months of data collected by the spacecraft from May 2009 to early January 2010.

"All of Kepler's best capabilities have converged to yield the first solid evidence of a rocky planet orbiting a star other than our sun," said Natalie Batalha, Kepler's deputy science team lead at NASA's Ames Research Center in Moffett Field, Calif., and primary author of a paper on the discovery accepted by the Astrophysical Journal. "The Kepler team made a commitment in 2010 about finding the telltale signatures of small planets in the data, and it's beginning to pay off."

Kepler's ultra-precise photometer measures the tiny decrease in a star's brightness that occurs when a planet crosses in front of it. The size of the planet can be derived from these periodic dips in brightness. The distance between the planet and the star is calculated by measuring the time between successive dips as the planet orbits the star.

Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zone, the region in a planetary system where liquid water can exist on the planet's surface. However, since it orbits once every 0.84 days, Kepler-10b is more than 20 times closer to its star than Mercury is to our sun and not in the habitable zone.

Kepler-10 was the first star identified that could potentially harbor a small transiting planet, placing it at the top of the list for ground-based  observations with the W.M. Keck Observatory 10-meter telescope in Hawaii.

Scientists waiting for a signal to confirm Kepler-10b as a planet were not disappointed. Keck was able to measure tiny changes in the star's spectrum, called Doppler shifts, caused by the telltale tug exerted by the orbiting planet on the star.

The discovery of Kepler 10-b is a significant milestone in the search for planets similar to our own," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Although this planet is not in the habitable zone, the exciting find showcases the kinds of discoveries made possible by the mission and the promise of many more to come," he said.

Knowledge of the planet is only as good as the knowledge of the star it orbits. Because Kepler-10 is one of the brighter stars being targeted by Kepler, scientists were able to detect high frequency variations in the star's brightness generated by stellar oscillations, or starquakes.

This analysis allowed scientists to pin down Kepler-10b's properties.

There is a clear signal in the data arising from light waves that travel within the interior of the star. Kepler Asteroseismic Science Consortium scientists use the information to better understand the star, just as earthquakes are used to learn about Earth's interior structure. As a result of this analysis, Kepler-10 is one of the most well characterized planet-hosting stars in the universe.

That's good news for the team studying Kepler-10b. Accurate stellar properties yield accurate planet properties. In the case of Kepler-10b, the picture that emerges is of a rocky planet with a mass 4.6 times that of Earth and with an average density of 8.8 grams per cubic centimeter -- similar to that of an iron dumbbell.

Source: NASA Science News

Artists concept of the Kepler Space Telescope with distant solar system. Credit: NASA.

NASA's Kepler space telescope, designed to find Earth-size planets in the habitable zone of sun-like stars, has discovered its first five new exoplanets. (read more)