Astronomers Discover Planetary Odd Couple

Astronomers have discovered a pair of neighboring planets with dissimilar densities orbiting very close to each other. The planets are too close to their star to be in the so-called "habitable zone," the region in a system where liquid water might exist on the surface, but they have the closest-spaced orbits ever confirmed. The findings are published today in the journal Science.

The research team, led by Josh Carter, a Hubble fellow at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and Eric Agol, a professor of astronomy at the University of Washington in Seattle, used data from NASA's Kepler space telescope, which measures dips in the brightness of more than 150,000 stars, to search for transiting planets.

The inner planet, Kepler-36b, orbits its host star every 13.8 days and the outer planet, Kepler-36c, every 16.2 days. On their closest approach, the neighboring duo comes within about 1.2 million miles of each other. This is only five times the Earth-moon distance and about 20 times closer to one another than any two planets in our solar system.

Kepler-36b is a rocky world measuring 1.5 times the radius and 4.5 times the mass of Earth. Kepler-36c is a gaseous giant measuring 3.7 times the radius and eight times the mass of Earth. The planetary odd couple orbits a star slightly hotter and a couple billion years older than our sun, located 1,200 light-years from Earth

To read more about the discovery, visit: the Harvard-Smithsonian Center for Astrophysics and University of Washington press releases.

Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., managed the Kepler mission's development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

Michele Johnson

Ames Research Center, Moffett Field, Calif.

650-604-6982

michele.johnson@nasa.gov

Small Planets Don't Need Stars With Heavy Metal Content To Form

J.D. Harrington

Headquarters, Washington                                   

202-358-5241

j.d.harrington@nasa.gov

 

Michele Johnson

Ames Research Center, Moffett Field, Calif.

650-604-6982

michele.johnson@nasa.gov

 

WASHINGTON -- 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.

A research team led by Lars A. Buchhave, an astrophysicist at the Niels Bohr Institute and the Centre for Star and Planet Formation at the University of Copenhagen, studied the elemental composition of more than 150 stars harboring 226 planet candidates smaller than Neptune.

"I wanted to investigate whether small planets needed a special environment in order to form, like the giant gas planets, which we know preferentially develop in environments with a high content of heavy elements," said Buchhave. "This study shows that small planets do not discriminate and form around stars with a wide range of heavy metal content, including stars with only 25 percent of the sun's metallicity." 

Astronomers refer to all chemical elements heavier than hydrogen and helium as metals. They define metallicity is the metal content of heavier elements in a star. Stars with a higher fraction of heavy elements than the sun are considered metal-rich. Stars with a lower fraction of heavy elements are considered metal-poor.

Planets are created disks of gas and dust around new stars. Planets like Earth are composed almost entirely of elements such as iron, oxygen, silicon and magnesium.

The metallicity of a star mirrors the metal content of the planet-forming disk. Astronomers have hypothesized that large quantities of heavy elements in the disk would lead to more efficient planet formation. It has long been noted that giant planets with short orbital periods tend to be associated with metal-rich stars.

Unlike gas giants, the occurrence of smaller planets is not strongly dependent on the heavy element content of their host stars. Planets up to four times the size of Earth can form around stars with a wide range of heavy element content, including stars with a lower metallicity than the sun. The findings are described in a new study published in the journal Nature.

"Kepler has identified thousands of planet candidates, making it possible to study big-picture questions like the one posed by Lars. Does nature require special environments to form Earth-size planets?" said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center at Moffett Field, Calif. "The data suggest that small planets may form around stars with a wide range of metallicities -- that nature is opportunistic and prolific, finding pathways we might otherwise have thought difficult."

The ground-based spectroscopic observations for this study were made at the Nordic Optical Telescope on La Palma in the Canary Islands; Fred Lawrence Whipple Observatory on Mt. Hopkins in Ariz.; McDonald Observatory at the University of Texas at Austin; and W.M. Keck Observatory atop Mauna Kea in Hawaii.

Launched in March 2009, Kepler searches for planets by continuously monitoring more than 150,000 stars, looking for telltale dips in their brightness caused by passing, or transiting, planets. At least three transits are required to verify a signal as a planet. Follow-up observations from ground-based telescopes are also needed to confirm a candidate as a planet.

Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed the Kepler mission development.

Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

For more information about the Kepler mission, visit http://www.nasa.gov/kepler.

- end -

NASA Schedules Hubble Science Update For May 31 (Update Time Change)

J.D. Harrington

Headquarters, Washington                                   

202-358-5241

j.d.harrington@nasa.gov

 

Ray Villard

Space Telescope Science Institute, Baltimore

410-338-4514

villard@stsci.edu

 

WASHINGTON -- NASA will host a Science Update Thursday, May 31, at 1:00 p.m. EDT to discuss new Hubble Space Telescope observations that allow astronomers to predict with certainty the next major cosmic event to affect our entire galaxy, sun, and solar system.

The news conference will be held in NASA Headquarters' James E. Webb Auditorium at 300 E St. SW in Washington and be shown live on NASA Television and on the agency's website.

It has been known for a long time that the Andromeda galaxy is approaching us. Because of uncertainties in Andromeda's motion, it has not been possible to determine whether the Milky Way will have a head-on collision or glancing blow with the neighboring galaxy billions of years in the future. Hubble's precise observations will settle this question.

The briefing participants are:

-- Roeland van der Marel, astronomer, Space Telescope Science Institute, Baltimore

-- Sangmo Tony Sohn, astronomer, Space Telescope Science Institute, Baltimore

-- Rosemary Wyse, professor, Physics and Astronomy, Johns Hopkins University, Baltimore

-- John Grunsfeld, Associate Administrator, Science Mission Directorate, NASA Headquarters, Washington

Media can attend the event or ask questions by phone. For dial-in information, reporters must send an email listing their name, phone number and media affiliation to j.d.harrington@nasa.gov by noon on May 31.

Following the news conference, the panelists also will host a web chat at 3 p.m. to answer questions from the general public. Participate by visiting http://www.nasa.gov/connect/chat/M31_collision_chat.html.

For NASA TV downlink information, schedules and links to streaming video, visit http://www.nasa.gov/ntv.

For more information about NASA's Hubble Program, visit http://www.nasa.gov/hubble.

- end -

Hubble's 22nd Anniversary Image Shows Turbulent Star-Making Region

J.D. Harrington

Headquarters, Washington

202-358-5241

j.d.harrington@nasa.gov

 

Ray Villard / Cheryl Gundy

Space Telescope Science Institute, Baltimore, Md.

410-338-4514 / 410-338-4707

villard@stsci.edu / gundy@stsci.edu

WASHINGTON -- Several million young stars are vying for attention in a new NASA Hubble Space Telescope image of a raucous stellar breeding ground in 30 Doradus, a star-forming complex located in the heart of the Tarantula nebula.

The new image comprises one of the largest mosaics ever assembled from Hubble photos and includes observations taken by Hubble's Wide Field Camera 3 and Advanced Camera for Surveys. NASA and the Space Telescope Science Institute (STScI) in Baltimore released the image today in celebration of Hubble's 22nd anniversary.

"Hubble is the world's premiere science instrument for making celestial observations, which allow us to unravel the mysteries of the universe," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington and three-time Hubble repair astronaut. "In recognition of Hubble's 22nd birthday, the new image of the 30 Doradus region, the birth place for new stars, is more than a fitting anniversary image."

30 Doradus is the brightest star-forming region in our galactic neighborhood and home to the most massive stars ever seen. The nebula is 170,000 light-years away in the Large Magellanic Cloud, a small satellite galaxy of the Milky Way. No known star-forming region in our galaxy is as large or as prolific as 30 Doradus.

Collectively, the stars in the image are millions of times more massive than our sun. The image is roughly 650 light-years across and contains some rambunctious stars, including one of the fastest rotating stars and the highest velocity stars ever observed by astronomers.

The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the stars' birth and evolution. Many small galaxies have more spectacular starbursts, but the Large Magellanic Cloud's 30 Doradus is one of the only star-forming regions that astronomers can study in detail. The star-birthing frenzy in 30 Doradus may be fueled partly by its close proximity to its companion galaxy, the Small Magellanic Cloud.

The image reveals the stages of star birth, from embryonic stars a few thousand years old and still wrapped in cocoons of dark gas, to behemoths that die young in supernova explosions. 30 Doradus churns out stars at a furious pace over millions of years. Hubble shows star clusters of various ages, from about 2 million to 25 million years old.

The region's sparkling centerpiece is a giant, young star cluster named NGC 2070, only 2 million to 3 million years old. Its stellar inhabitants number roughly 500,000. The cluster is a hotbed for young, massive stars. Its dense core, known as R136, is packed with some of the heftiest stars found in the nearby universe, weighing more than 100 times the mass of our sun.

The massive stars are carving deep cavities in the surrounding material by unleashing a torrent of ultraviolet light, which is winnowing away the enveloping hydrogen gas cloud in which the stars were born. The image reveals a fantastic landscape of pillars, ridges and valleys. Besides sculpting the gaseous terrain, the brilliant stars may be triggering a successive generation of offspring. When the ultraviolet radiation hits dense walls of gas, it creates shocks, which may generate a new wave of star birth.

The image was made using 30 separate fields, 15 from each camera. Both cameras made these observations simultaneously in October 2011. The colors in the image represent the hot gas that dominates regions of the image. Red signifies hydrogen gas and blue represents oxygen.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. STScI conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington.

For related images, video and more information about Hubble, visit http://www.nasa.gov/hubble and http://hubblesite.org.

- end -