Posted on by Matt Williams

Starshade Prepares To Image New Earths

Artist's concept of the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets. Credit: NASA/JPL
Artist's concept of the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets. Credit: NASA/JPL

For countless generations, people have looked up at the stars and wondered if life exists somewhere out there, perhaps on planets much like ours. But it has only been in recent decades that we have been able to confirm the existence of extrasolar planets (aka. exoplanets) in other star systems. In fact, between 1988 and April 20th of 2016, astronomers have been able to account for the existence of 2108 planets in 1350 different star systems, including 511 multiple planetary systems.

Most of these discoveries have taken place within just the past three years, thanks to improvements in our detection methods, and the deployment of the Kepler space observatory in 2009. Looking ahead, astronomers hope to improve on these methods even further with the introduction of the Starshade, a giant space structure designed to block the glare of stars, thus making it easier to find planets – and perhaps another Earth!

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Posted on by Tammy Plotner

Russia Will Begin Hunt For Extrasolar Planets

Russia to Start Own Search for Extrasolar Planets - Photo: Paul A. Kempton

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Located just south of Saint Petersburg on Pulkovo Heights, one of the greatest Russian Observatories of all times – the Pulkovo Observatory – is about to embark on a very noble study. According to the head of the Institute for Space Research, Lev Zelyony, the Soviet telescopes are about to turn their eyes towards deep skies in search of extrasolar planets. “Scientists from the Pulkovo Observatory are planning to use ground-based instruments to study the transit of planets around their parent stars,” Zelyony said at a roundtable meeting at RIA Novosti headquarters in Moscow.

The observatory was absolutely state-of-the-art when it opened for business in 1839 and employed Wilhelm von Struve as its director. It houses some of the largest refractor telescopes in the world, including a 38-cm (15 in.) aperture refractor and a 30-inch (76 cm) refractor – both built by Alvan Clarke and Sons. Fifty years later, they added an astrophysical laboratory, a mechanical workshop and installed one of Europe’s largest lensed telescope, a 76-cm refractor (30 inch). Later additions to the observatory included a Littrow spectrograph and horizontal solar telescope and the facility blossomed into a world leader in stellar spectroscopy, cataloging and more. Modern improvements include astrograph equipment, an interferometer, radio telescope and even an additional 65-cm (26-inch) refractor. The Pulkovo Observatory is up to the task.

Pulkovo Observatory 2004 - Credit: Vladimir Ivanov

The hunt for exoplanets is one of the most popular aspects of modern astronomy and one of the fastest growing fields. In less than 25 years, 755 and an ever-increasing number of planets have been cataloged… and the research just doesn’t end. The United States Kepler Mission and French CoRoT space telescope have had their share of fun, but using a ground-based telescope could also be a viable source of planet detection, Zelyony said. He also cited the example of the Hungarian Automated Telescope Network (HATNet) which so far has discovered 29 exoplanets. By using the transit detection method, the Russian astronomers are eager to begin observations where a small change in magnitude could mean a big change in the way their telescopes perceive the stars.

“It is an interesting research, which should be pursued,” Zelyony said. “It will also help us look at our Solar System from a different perspective.”

Original Story Source: Rionovosti News Release.

Posted on by Tammy Plotner

11 New Planetary Systems… 26 New Planets… Kepler Racks ‘Em Up!

Artist's Concept of New Planetary Systems - Credit: NASA

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Eleven ball in the side pocket. Whack! And another 26 planets are discovered! NASA just announced the latest tally and the new discoveries come close to doubling the amount of verified planets and tripling the number of stars which are confirmed to have more than one transiting planet. It’s just another score for understanding how planets came to be… planets which run the gambit from about one and half times the size of Earth up to the size of Jupiter. Of these, fifteen are judged to be between the size of Earth and Neptune – while more observations will reveal their structure. The new bodies orbit the parent star between 6 and 143 days and all are closer than our Sun/Venus distance.

“Prior to the Kepler mission, we knew of perhaps 500 exoplanets across the whole sky,” said Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington. “Now, in just two years staring at a patch of sky not much bigger than your fist, Kepler has discovered more than 60 planets and more than 2,300 planet candidates. This tells us that our galaxy is positively loaded with planets of all sizes and orbits.”

Kepler is a busy-body. It monitors the brightness changes in more than 150,000 stars. Through repeated measurements, it is able to pick out minute magnitude fluctuations which occur as a planet passes between us, Kepler and the parent sun. The newly documented solar systems are host to between two and five closely situated transiting bodies. In such cramped systems, the gravitational interaction between the orbiting members means some are accelerated – and others decelerated – in their tracks. Faster orbital speeds account for changes in orbital periods… Changes that the Kepler mission documents as Transit Timing Variations (TTVs). For planetary systems possessing TTVs, no extreme study with ground-based telescopes is required to verify their existence and the technique allows Kepler to validate the presence of planetary systems around further and fainter stars.

What’s been found? Five of the systems documented as Kepler-25, Kepler-27, Kepler-30, Kepler-31 and Kepler-33, are home to a set of planets whose orbits double each other. The outer body orbits twice for every inner body orbit. Four of the systems, Kepler-23, Kepler-24, Kepler-28 and Kepler-32, are home to a pairing where the outer planet circles the star twice for every three times the inner planet orbits.

“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 Particle Astrophysics in Batavia, Ill., and lead author of a paper confirming four of the systems.

And now for the game ball… Kepler-33 had the most planets of all. With a parent star older and more massive than Sol, the system gives rise to five planets whose sizes run between one and a half to five times the size of Earth. But, this is one crowded grouping. All of the planets orbiting this star are closer than Mercury is to our Sun! Thanks to stellar properties, Kepler is able to distinguish planets like these. The drop in the sun’s brightness and the length of time it takes for the planet to transit all play a role in determining presence. With similar signatures verified around the same star, chances of false readings are unlikely.

“The approach used to verify the Kepler-33 planets shows the overall reliability is quite high,” said Jack Lissauer, planetary scientist at NASA Ames Research Center at Moffett Field, Calif., and lead author of the paper on Kepler-33. “This is a validation by multiplicity.”

Original Story Source: NASA News Release.