Choose Your Star: First Gaia Data Release Catalogs More than Billion Celestial Objects

Tuesday, July 25, 2017

Choose Your Star: First Gaia Data Release Catalogs More than Billion Celestial Objects

Choose Your Star: First Gaia Data Release Catalogs More than Billion Celestial Objects:

Gaia's first sky map. Credit: ESA/Gaia/DPAC. Acknowledgement: A. Moitinho & M. Barros (CENTRA – University of Lisbon), on behalf of DPAC.

European Space Agency’s (ESA) Gaia satellite is on a crucial mission to create the most detailed ever 3D map of our Milky Way galaxy. Last year, the agency has published first data release provided by Gaia, which contains more than one billion stars with information about their brightness and precise position on the sky.

Finding an interesting star could be now as easy as browsing offers in order to find the best car for you on websites like Cars.com. Just like this site lists a plenitude of models from Acura to Volvo, the Gaia Data Release 1 (or DR1 for short) allows astronomers to investigate a variety of peculiar objects in the sky. While car buyers and enthusiasts can choose among a diversity of models, including Toyota Gaia, the scientific community has its own Gaia, flying in space and delivering essential astronomical data.

DR1 is a real treasure trove for astronomers studying stars in our galaxy. The catalog consists of astrometry and photometry data for over one billion sources brighter than magnitude 20.7 in the white-light photometric band G of the Gaia satellite. It is the largest all-sky survey of celestial objects to date.

ESA scientists underline that DR1 shows the density of stars measured by Gaia across the entire sky, and confirms that it has already collected superb data since the beginning of its operational life in July 2014. They note that the satellite charts the sky at precision that have never been achieved before.

In particular, DR1 contains about 1.14 billion stars with precise measurements of their position on the sky and brightness. The dataset allows astronomers to estimate distance and proper motion for over two billion stars in common with the earlier Hipparcos and Tycho-2 catalogs, based on data from ESA's Hipparcos mission. Moreover, DR1 also contains nearly 3,200 variable stars, including details about their brightness variations as well as positions and brightness of more than 2,000 quasi-stellar objects (quasars).

The promising results provided by DR1 leave the researchers hungry for more. Gaia mission scientists are convinced that subsequent data releases will revolutionize our understanding of how stars are distributed and move across the Milky Way.

“1,000 days after launch and thanks to the great work of everyone involved, we are thrilled to present this first dataset and are looking forward to the next release, which will unleash Gaia’s potential to explore our galaxy as we have never seen it before,” Fred Jansen, Gaia mission manager at ESA, said on September 14, 2016, when DR1 was published.

In general, DR1 confirms that Gaia is well on track of achieving it main goal – charting the positions, distances, and motions of one billion stars. It will be a 3D map of about one percent of the Milky Way’s stellar content – all with an unprecedented accuracy. Gaia’s second data release is currently planned for April 2018.

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The National Aeronautics and Space Administration (NASA) is the United States government agency responsible for the civilian space program as well as aeronautics and aerospace research. President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA's predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

UFO SIGHTINGS PHOTO PHOTOGRAPHY

The Oxford English Dictionary defines a UFO as "An unidentified flying object; a 'flying saucer'." The first published book to use the word was authored by Donald E. Keyhoe. The acronym "UFO" was coined by Captain Edward J. Ruppelt, who headed Project Blue Book, then the USAF's official investigation of UFOs. He wrote, "Obviously the term 'flying saucer' is misleading when applied to objects of every conceivable shape and performance. For this reason the military prefers the more general, if less colorful, name: unidentified flying objects. UFO (pronounced Yoo-foe) for short." Other phrases that were used officially and that predate the UFO acronym include "flying flapjack", "flying disc", "unexplained flying discs", "unidentifiable object", and "flying saucer". The phrase "flying saucer" had gained widespread attention after the summer of 1947. On June 24, a civilian pilot named Kenneth Arnold reported seeing nine objects flying in formation near Mount Rainier. Arnold timed the sighting and estimated the speed of discs to be over 1,200 mph (1,931 km/h). At the time, he described the objects' shape as being somewhat disc-like or saucer-like, leading to newspaper accounts of "flying saucers" and "flying discs". In popular usage the term UFO came to be used to refer to claims of alien spacecraft. and because of the public and media ridicule associated with the topic, some investigators prefer to use such terms as unidentified aerial phenomenon (or UAP) or anomalous phenomena, as in the title of the National Aviation Reporting Center on Anomalous Phenomena (NARCAP).

UFO PHOTO PHOTOGRAPHY

UFO - Unidentified Flying Object An unidentified flying object, or UFO, in its most general definition, is any apparent anomaly in the sky that is not identifiable as a known object or phenomenon. Culturally, UFOs are associated with claims of visitation by extraterrestrial life or government-related conspiracy theories, and have become popular subjects in fiction. While UFOs are often later identified, sometimes identification may not be possible owing to the usually low quality of evidence related to UFO sightings (generally anecdotal evidence and eyewitness accounts). Stories of fantastical celestial apparitions have been told since antiquity, but the term "UFO" (or "UFOB") was officially created in 1953 by the United States Air Force (USAF) to serve as a catch-all for all such reports. In its initial definition, the USAF stated that a "UFOB" was "any airborne object which by performance, aerodynamic characteristics, or unusual features, does not conform to any presently known aircraft or missile type, or which cannot be positively identified as a familiar object." Accordingly, the term was initially restricted to that fraction of cases which remained unidentified after investigation, as the USAF was interested in potential national security reasons and/or "technical aspects" (see Air Force Regulation 200-2). During the late 1940s and through the 1950s, UFOs were often referred to popularly as "flying saucers" or "flying discs". The term UFO became more widespread during the 1950s, at first in technical literature, but later in popular use. UFOs garnered considerable interest during the Cold War, an era associated with a heightened concern for national security. Various studies have concluded that the phenomenon does not represent a threat to national security nor does it contain anything worthy of scientific pursuit (e.g., 1951 Flying Saucer Working Party, 1953 CIA Robertson Panel, USAF Project Blue Book, Condon Committee).

Photos of Nature | Nature Photography What is The Universe

Photos of Nature | Nature Photography What is The Universe

Tuesday, July 25, 2017