Astronomers create best ever image of star outside our Solar System

Tuesday, September 12, 2017

Astronomers create best ever image of star outside our Solar System

Astronomers create best ever image of star outside our Solar System:

VLTI reconstructed view of the surface of Antares

Using ESO’s Very Large Telescope Interferometer astronomers have constructed this image of the red supergiant star Antares. This is the most detailed image ever of this object, or any other star apart from the Sun. Image & Caption Credit: K. Ohnaka / ESO

A map of activity on the surface and in the atmosphere of the star Antares by a team of astronomers is considered to be the most detailed ever created for a star other than the Sun. The red supergiant is located some 550 light-years distant in the constellation Scorpius and is in its final stages of its existence. It will eventually die in a supernova explosion.

While Antares likely started its life with about 15 times the mass of our Sun, it is now shedding mass and is estimated to have lost about three solar masses. Its current diameter is approximately 700 times that of the Sun.

Researchers led by Keiichi Ohnaka of the Universidad Catolico del Norte in Chile used the European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI) at Paranal Observatory to map the surface of the luminous, low-density star and measure the speed at which surface material is moving.

The VLTI is an instrument composed of several telescopes that create the equivalent of a single large telescope with a mirror boasting a diameter up to 656 feet (200 meters). It combines the light from as many as four telescopes, including either the 26.9-foot (8.2-meter) Unit Telescopes or the 5.9-foot (1.8-meter) Auxiliary Telescopes, enabling scientists to view the star in incredible detail.

Artist’s impression of the red supergiant star Antares

This artist’s impression shows the red supergiant star Antares in the constellation of Scorpius. Image & Caption Credit: M. Kornmesser / ESO

Using three Auxiliary Telescopes along with the near-infrared AMBER instrument, astronomers imaged several locales on Antares’ surface in various infrared wavelengths to measure the speed at which gases are moving in these different regions and across the entire star. The technique yielded the most detailed map of surface activity by atmospheric gases on any star besides our Sun.

Ohnaka said a central goal of the study is to determine how stars like Antares lose so much mass at the end of their lives.

“The VLTI is the only facility that can directly measure the gas motions in the extended atmosphere of Antares – a crucial step towards clarifying this problem. The next challenge is to identify what’s driving the turbulent motions,” Ohnaka said.

VLTI velocity map of the surface of Antares

This is the first such velocity map of any star other than the Sun. In red regions, the material is moving away from Earth, and in the blue areas, the material is approaching. The empty region around the star is not a real feature but shows where velocity measurements were not possible. Image & Caption Credit: K. Ohnaka / ESO

Low-density gas was discovered extending much further from the star than the researchers expected, leading them to conclude it was brought there by a process other than convection, which involves the transfer of energy from a star’s core to its outer atmosphere. Just what that process is remains unknown.

Other stars of various types will need to be studied using the technique astronomers used to map Antares in the same degree of detail for scientists to determine what that process is, Ohnaka said.

“Our work brings stellar astrophysics to a new dimension and opens an entirely new window to observe stars,” Ohnaka said.

Ohnaka is the lead author of a paper on the study published in the journal Nature.

The bright red star Antares in the constellation of Scorpius

This chart shows the constellation of Scorpius. At the heart of this grouping of stars lies the bright red supergiant star Antares. Image & Caption Credit: ESO / IAU / Sky & Telescope

This article was updated at 16:55 EDT on Aug. 27, 2017, with distance to Antares.

The post Astronomers create best ever image of star outside our Solar System appeared first on SpaceFlight Insider.

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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, September 12, 2017