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Remarkable discoveries from the first year of the TESS mission



  NASA's TESS Mission Completes the First Year of Surveying

Illustration of L 98-59b, the smallest exoplanet discovered by NASA's Exoplanet Surveying Satellite. Credit: NASA's Goddard Space Flight Center / Ravyn Cullor

NASA's Transiting Exoplanet Survey Satellite ( TESS ) has discovered 21 planets outside our solar system and other interesting events in the southern skies during its first event covers year of science. TESS has now turned to the northern hemisphere to undertake the most comprehensive planet hunt expedition ever undertaken.

TESS began hunting for exoplanets (or worlds orbiting distant stars) in the southern sky in July 2018, collecting data on supernovae, black holes, and other phenomena in its line of sight. Together with the planets discovered by TESS, the mission has identified over 850 candidate exoplanets awaiting confirmation by ground-based telescopes.

"The pace and productivity of TESS in its first year of operation far exceeded our most optimistic hopes for the mission," said George Ricker, senior investigator of TESS at the Massachusetts Institute of Technology, Cambridge. "TESS has not only found a variety of exoplanets, but also discovered a treasure trove of astrophysical phenomena, including thousands of highly variable star objects."

To search for exoplanets, TESS uses four large cameras to produce a 24-by-96 -Grade section of the sky for every 27 days. Some of these sections overlap so that some parts of the sky are observed for almost a year. Focusing on stars closer than 300 light-years from our solar system, TESS looks for passages that are periodic dips in brightness caused by an object like a planet passing in front of the star.

On July 18, the southern part of the survey was completed, and the spacecraft turned its cameras north. When the northern section is completed in 2020, TESS will have charted three quarters of the sky.

"Kepler discovered the amazing result that on average every star system has a planet or planets around it," said Padi Boyd. TESS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "TESS is taking the next step. If there are planets everywhere, let us find the orbiting bright stars nearby, because they are the ones we can now pursue with existing ground-based and space-based telescopes and the next generation of instruments for decades to come. "


Here are highlights from TESS's first year of scientific operations. All exoplanet animations are illustrations. Credits: NASA's Goddard Space Flight Center

Here are some of the interesting objects and events that TESS saw in its first year.

Exoplanets

To qualify as an exoplanet candidate, an object must undergo at least three transits in the TESS data and then undergo several additional tests to ensure that the transits do not pass through one Solar eclipse or a companion star caused false positives, but may actually be an exoplanet. Once a candidate is identified, astronomers use a large network of ground-based telescopes to confirm this.

"The team is currently focusing on finding the best candidates that can be confirmed by ground-based follow-up," said Natalia Guerrero, head of the team responsible for identifying exoplanet candidates at MIT responsible is. "But there are many more potential exoplanet candidates in the data that still needs to be analyzed, so we only see the tip of the iceberg here." TESS just scratched the surface.

The planets that TESS has discovered range from a world of 80% of Earth's size to those comparable to or exceeding those of Jupiter and Saturn. Like Kepler, TESS finds many planets smaller than Neptune but larger than Earth.

While NASA is trying to send astronauts to some of our closest neighbors – the Moon and Mars – to learn more about the planets in our solar system, we can detect them by observing with powerful telescopes the planet TESS has discovered better understand the formation of the earth and the solar system.

Using TESS's data, scientists are using current and future observatories such as the James Webb Space Telescope will be able to study other aspects of exoplanets, such as the presence and composition of any atmosphere that would affect their ability to To develop life.

Comets

Before scientific operations began, TESS snatched clear images of a newly discovered comet in our solar system. In instrumental orbital testing, the satellite's cameras took a series of images that captured the motion of C / 2018 N1, a comet landing on June 29 from the NASA Near-Earth Object Wide Field Infrared Survey Explorer (NEOWISE). was found.

TESS also collected data on similar objects outside the solar system.

Exokometen

Data from the mission were also used to identify transits from comets orbiting another star: Beta Pictoris, which lies 63 light-years away. Astronomers could find three comets that were too small to be planets and had detectable tails. This was the first identification of their type in visible light.

Supernovae

Because TESS spends nearly a month looking around At the same place, it can gather data on star events such as supernovae as they begin. In the early months of his scientific work, TESS discovered six supernovae in distant galaxies that were later discovered by ground-based telescopes.

Scientists hope to use these types of observations to better understand the origins of a particular explosion known as an Ia supernova.

Type Ia supernovae occur either in star systems in which a white dwarf receives gas from another star, or when two white dwarfs converge. Astronomers do not know which case is more common, but with TESS data they can better understand the origins of these cosmic explosions.

Type Ia supernovae are a class of objects called "standard candles". That is, astronomers know how bright they are, and can use them to calculate how fast the universe expands. Using TESS data, they can understand the differences between type Ia supernovae that have arisen in both circumstances. This could have a major impact on how we understand events that take place billions of light-years away, and ultimately the fate of the universe.

TESS is a NASA Astrophysics Explorer mission, managed and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland. Dr. George Ricker of the Kavli Institute for Astrophysics and Space Research of the MIT acts as principal investigator for the mission. Other partners include Northrop Grumman of Falls Church, Virginia; NASA's Ames Research Center in Silicon Valley, California; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; The Lincoln Laboratory of MIT in Lexington, Massachusetts; and the Space Telescope Science Institute in Baltimore. Over a dozen universities, research institutes and observatories worldwide participate in the mission.


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