Astronomy: Venus' Transit and the Search for Other Worlds

Hi My Friends: A VUELO DE UN QUINDE EL BLOG., t's the final opportunity of the century to witness the rare astronomical reunion of the sun, Venus and Earth. On Tuesday, June 5 or 6, 2012 depending on your location, Venus will make its presence in the solar system visible from Earth’s day side. Viewers will see Venus as a small dot slowly drifting across the golden disk of the sun.

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The First Recorded Transit of Venus

William Crabtree (1610–1644) was an astronomer, mathematician, and merchant from what is now Greater Manchester, England. He was one of only two people to observe and record the first predicted transit of Venus in 1639.

Credit: Ford Madox Brown, mural at Manchester Town Hall

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Light Curve of a Planet Transiting Its Star

Transit data are rich with information. By measuring the depth of the dip in brightness and knowing the size of the star, scientists can determine the size or radius of the planet. The orbital period of the planet can be determined by measuring the elapsed time between transits. Once the orbital period is known, Kepler's Third Law of Planetary Motion can be applied to determine the average distance of the planet from its stars.
Credit: NASA Ames

Venus' Transit and the Search for Other Worlds

It's the final opportunity of the century to witness the rare astronomical reunion of the sun, Venus and Earth. On Tuesday, June 5 or 6, 2012 depending on your location, Venus will make its presence in the solar system visible from Earth’s day side. Viewers will see Venus as a small dot slowly drifting across the golden disk of the sun.

Transits of Venus are very rare, separated by more than a hundred years. There have been 53 transits since 2000 B.C. but only six have been witnessed since the invention of the telescope in 1608. These rare events occur in pairs, with the first transit occurring June 8, 2004. The next opportunity won't be until Dec. 10-11, 2117.

Jeremiah Horrocks and William Crabtree, two young astronomers from England, recorded the first observation of a transit in 1639. In 1769, survey crews, including Captain James Cook, gathered transit data from various locations around the world that were later used to calculate the distance between Earth and the sun, thereby establishing the solar system's scale.

"Throughout history, astronomers have creatively used nature's coincidences as opportunities to learn something new about the universe," said Natalie Batalha, Kepler mission scientist at NASA Ames Research Center, Moffett Field, Calif. "Today is no different. As Venus crosses the disk of the sun, her shadow sweeps across the face of Earth in the same way that the shadows cast by distant exoplanets sweep across the face of the Kepler photometer."

Today, transit events are used to detect planets beyond the solar system. NASA's Kepler space telescope continuously measures changes in brightness of more than 150,000 stars to detect when a planet passes or transits in front of a star. Kepler does not directly image distant planets, as they are too far away.

Different size planets block different amounts of starlight. Kepler's exquisitely precise photometer, or light sensor, is designed to detect fractional changes in brightness. For an Earth-size planet transiting a sun-like star, the change in brightness is only 84 parts per million. That is less than 1/100th of one percent, or the equivalent of the amount of light blocked if a gnat crawled across a car’s headlight viewed from several miles away.

Transit data are rich with information. By measuring the depth of the dip in brightness and knowing the size of the star, scientists can determine the size or radius of the planet. The orbital period of the planet can be determined by measuring the elapsed time between transits. Once the orbital period is known, Kepler's Third Law of Planetary Motion can be applied to determine the average distance of the planet from its stars.

Using the transit method, the Kepler mission has identified 61 planets and more than 2,300 planet candidates during the spacecraft's first 16 months of observation from May 2009 to September 2010.

For information about the Kepler Mission, click here.

For more information about the worldwide events, safety precautions for viewing, educational content and social media activities, click here.

The public can follow the event on Twitter on #VenusTransit and download a free mobile app here. 

 NASA

 Guillermo Gonzalo Sánchez Achutegui
 ayabaca@gmail.com
 ayabaca@hotmail.com
 ayabaca@yahoo.com
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ASTRONOMY: Kepler's Quest for New Worlds Public Talk

Hi My Friends: A VUELO DE UN QUINDE EL BLOG., Humankind's speculation about the existence of other worlds like our own turned into a veritable quest with the launch of NASA's Kepler spacecraft in March 2009. The mission is designed to survey a slice of the Milky Way to identify planets orbiting other stars. It looks for the telltale dimming of light that occurs when an orbiting planet passes in front of the star thereby casting a shadow into space. The roster of exoplanets discovered by Kepler has reached close to 30 in number, including one world that is unquestionably rocky in composition, another with 6 transiting planets, and another in a circumbinary orbit. Moreover, the team has released a catalog of nearly one thousand stars showing the recurring dimmings of light that suggest the presence of a planet. The methods used to identify planets will be described in this talk as well as the discoveries that have been announced to date. Now in its third year of operation, Kepler is honing in on the answer to the question that drives the mission: are potentially habitable worlds abundant in our galaxy.
Dr. Natalie Batalha is a professor of physics and astronomy at San Jose State University and the deputy science team lead for NASA's Kepler Mission. Biography: http://1.usa.gov/rScP5y

Kepler's Quest for New Worlds Public Talk http://keplerpublictalk.eventbrite.com/

Kepler's Quest for New Worlds Public Talk
12.06.11
Is life common in our galaxy? Does it exist? How unique is life here on Earth? Are we alone? The Kepler Mission is taking us one step closer to answer these age-old questions.

Join Dr. Natalie Batalha and Dr. Don Kurtz for a free public talk on NASA's Kepler Mission, NASA's first mission capable of detecting Earth-size planets around other stars, on Tuesday, Dec. 6 at 7 p.m. in building 152 at NASA Ames Research Center.

Catching Shadows: Kepler's Quest for New Worlds: Dr. Natalie Batalha,professor of physics and astronomy at San Jose State University and the deputy science team lead for NASA's Kepler Mission. Humankind's speculation about the existence of other worlds like our own turned into a veritable quest with the launch of NASA's Kepler spacecraft in March 2009. The mission is designed to survey a slice of the Milky Way to identify planets orbiting other stars. It looks for the telltale dimming of light that occurs when an orbiting planet passes in front of the star thereby casting a shadow into space. The roster of exoplanets discovered by Kepler has reached close to 30 in number, including one world that is unquestionably rocky in composition, another with 6 transiting planets, and another in a circumbinary orbit. Moreover, the team has released a catalog of nearly one thousand stars showing the recurring dimmings of light that suggest the presence of a planet. The methods used to identify planets will be described in this talk as well as the discoveries that have been announced to date. Now in its third year of operation, Kepler is honing in on the answer to the question that drives the mission: are potentially habitable worlds abundant in our galaxy.

Biography: http://www.nasa.gov/mission_pages/kepler/team/batalha.html

Songs of the Stars: the Real Music of the Spheres: Dr. Don Kurtz, professor of astrophysics at the University of Central Lancashire in the United Kingdom and a steering committee member of the Kepler Asteroseismic Science Consortium.

We humans are visual creatures. For us “seeing is believing.” The Pythagoreans 2500 years ago believed in a celestial “music of the spheres”, an idea that reverberated down the millennia in Western music, literature, art and science. Johannes Kepler (the namesake of the Kepler Mission) was so enamored with Pythagoras’s idea that in the early 1600s that he spent years trying to discover harmonic relationships among the periods of the planets in their orbits about the Sun, finally, disappointingly (for him), proving otherwise. Now we know that there is a real music of the spheres. The stars have sounds in them that we can use to see right to their very cores. This multi-media lecture looks at the relationship of music to stellar sounds. You will hear the real sounds of the stars and you will hear musical compositions where every member of the orchestra is a real (astronomical) star! You will also learn about some of the latest amazing discoveries from the Kepler Space Mission that lets us “hear” the stars 100 times better than with telescopes on the ground.

Biography: http://www.uclan.ac.uk/schools/computing_engineering_physical/dwkurtz.php Register today: Space is limited! The Kepler Mission has transformed our understanding of planetary systems and is rewriting textbooks. We invite all members of the public to join in an engaging and moving presentation of how Kepler is shaping the understanding of our place in the universe. To register, please visit:

http://keplerpublictalk.eventbrite.com/.

For information about NASA's Kepler Mission,

Please visit: http://www.nasa.gov/mission_pages/kepler/main/index.html.

Please note because the event is being held at a Federal Government facility, the following restrictions apply:
1.- Entry at the main gate for NASA and the Conference Center requires a government issued picture identification along with the ticket for the event. Visitors under the age of 18 must be accompanied by an adult with a government issued picture identification.
2.-Unauthorized entry upon any NASA real property of installation is prohibited. (14 CFR 1204.1004)
3.- Your entry into, continued presence on, or exit from, this installation is contingent upon your consent to inspection of person and property. (14 CFR 1204.1003)
4.- Unauthorized introduction of weapons or dangerous materials is prohibited
5.- Unless specifically authorized by NASA, you may not carry, transport, introduce, store, or use firearms or other dangerous weapons, explosives or other incendiary devices or other dangerous instruments or material likely to produce substantial injury or damage to persons or property. (14 CFR 1204.1003)
6.- Possession of firearms or dangerous weapons is strictly prohibited
7.- No Smoking
Guillermo Gonzalo Sánchez Achutegui
ayabaca@yahoo.com
ayabaca@gmail.com
ayabaca@hotmail.com
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ASTRONOMY: Kepler Mission Description

Hi My Friends: A VUELO DE UN QUINDE EL BLOG., The Kepler instrument is a specially designed 0.95-meter diameter telescope called a photometer or light meter. It has a very large field of view for an astronomical telescope 105 square degrees, which is comparable to the area of your hand held at arm's length. The fields of view of most telescopes are less than one square degree. Kepler needs the large field of view in order to observe the large number of stars. It stares at the same star field for the entire mission and continuously and simultaneously monitors the brightnesses of more than 100,000 stars for at least 3.5 years, the initial length of the mission, which can be extended.

Kepler Spacecraft and Photometer(Launched on March 6, 2009)

Kepler Scientific Objectives

The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. This is achieved by surveying a large sample of stars to:
1.- Determine the percentage of terrestrial and larger planets that are in or near the habitable zone of a wide variety of stars
2.- Determine the distribution of sizes and shapes of the orbits of these planets
3.- Estimate how many planets there are in multiple-star systems
4.- Determine the variety of orbit sizes and planet reflectivities, sizes, masses and densities of short-period giant planets
5.- Identify additional members of each discovered planetary system using other techniques
6.- Determine the properties of those stars that harbor planetary systems.

Image above: Kepler's targeted star field. Credit: Carter Roberts of the Eastbay Astronomical Society

Kepler Mission Star Field
An image by Carter Roberts of the Eastbay Astronomical Society in Oakland, CA, showing the Milky Way region of the sky where the Kepler spacecraft/photometer will be pointing. Each rectangle indicates the specific region of the sky covered by each CCD element of the Kepler photometer. There are a total of 42 CCD elements in pairs, each pair comprising a square. Credit: Carter Roberts

Kepler Mission Description
Kepler, a NASA Strategic mission launched into an Earth-trailing heliocentric orbit on March 6, 2009, is designed to stare at a 105 square degree region of the sky in the constellations of Cygnus and Lyra. The mission's goal is to obtain long-term, unfiltered, and precise light curves of up to 100,000 cool stars and search for periodic transits of planets as small as the Earth. A secondary objective of the mission is to study rapid oscillations of the target stars in order to determine their ages, radii, and metallic chemical compositions of planet-hosting stars. The Kepler Science page and Science Goals pages lay out the scientific objectives in some detail.
The science operations phase of the mission began on May 12, 2009. Since then Kepler has monitored the same sky field almost continuously. The principal exception is for monthly data downlinks during which the spacecraft must turn away from the monitored field, reorient toward the Earth for the downlink, and return to the field. The spacecraft also "rolls" every three months to allow for continous illumination of Kepler's solar arrays. A table of scheduled quarterly rolls, each lasting about 1 day, is given on the MAST/Kepler FAQ page (see FAQ tab in left "gutter"). The fields of view of 42 CCDs covers a four-way symmetrical pattern on the sky such that the same stars remain on the detectors during the mission. Although the Kepler field covers a large sky area containing millions of stars, data from small regions around only 150,000 targets are recorded and stored onboard the spacecraft. The default integration time is about 30 minutes, although a small number of asteroseismology and other targets of interest are recorded with integration times of about 1 minute.
The mission has a nominal lifetime of three and one half years to pursue its core science objectives. These objectives will be carried out by Science Principal Investigator William Borucki of NASA's Ames Research Center, the Kepler Science Team, the Kepler Participating Scientists, and the Kepler Asteroseismology Science Consortium. In addition, a limited Guest Observer (GO) program, dedicated to general (non-exoplanetary) astrophysics has been established. Proposal solicitations will be made on an annual basis, resources permitting, by NASA Headquarters. The GO program is administered from NASA's Ames Research Center. Information of interest to potential GO proposers can be found at the GO program website and in NASA's omnibus annual announcement Research Opportunities in Space and Earth Sciences 2010 NASA ROSES.
A map of where Kepler's Field of View in the sky was obtained from the Project and is shown below. Clicking on this image will bring up a magnified view. Users can reconnoiter the Kepler field in detail by going to the FFI display page.
Investigators interested in whether targets included in the MAST/Kepler ("KIC") database lie on any of the 42 Kepler detector fields should first consult the Kepler Target Search form. Users are also emphatically advised not to use solely color-derived quantities like Teff, logg, etc. to select their targets for proposals.
As the mission proceeds, the Project will periodically drop stars as exoplanetary search candidates. As it does so, MAST will provide access to lists of targets and/or data released as notifications in the Dropped Target and Published Target tabs under the Search and Retrieval item on the left banner of this page and in the Public Light Curves link in the Quick Links section above. As data become nonproprietary, the restrictions against accessing them, which are denoted by the "yellow band" on the Retrieval page, will disappear. In addition to the Dropped and Target lists, Kepler light curves and associated ground-based follow up data have been also placed on MAST's Kepler High Level Science Products site.
Image above: Kepler's targeted star field graphic. Credit: NASA

Target Field of View :
Since transits only last a fraction of a day, all the stars must be monitored continuously, that is, their brightnesses must be measured at least once every few hours. The ability to continuously view the stars being monitored dictates that the field of view (FOV) must never be blocked at any time during the year. Therefore, to avoid the Sun the FOV must be out of the ecliptic plane. The secondary requirement is that the FOV have the largest possible number of stars. This leads to the selection of a region in the Cygnus and Lyra constellations of our Galaxy as shown.

Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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