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How many planets will TESS find?



NASA's latest Exoplanet Hunt Space Telescope, TAS, was shot into action on Wednesday, April 18, 2018. As the name suggests, this telescope will use the Transit method to detect planets on Earth (ie rocky) around distant stars. In addition to other next-generation telescopes such as the James Webb Space Telescope (JWST), TESS will effectively emerge where telescopes such as Hubble and Kepler rose] But how many Planet awaits TESS? This was the subject of a new study by team researchers trying to estimate how many planets TESS is likely to discover and the physical properties of these planets and the stars they orbit. Overall, they estimate that during its two-year mission, TESS will orbit thousands of planets in a multitude of stars.

The study titled "A revised exoplanet energy from the Transit Exoplanet Survey Satellite (TESS)" was recently published online. The study was led by Thomas Barclay, an associate scientist at NASA's Goddard Space Flight Center and the University of Maryland, and included Joshua Pepper (an astrophysicist at Lehigh University) and Elisa Quintana (a research scientist at SETI Institute and NASA Ames)

As Thomas Barclay Universe Today emailed:

"TESS builds on Kepler's legacy Kepler was primarily a statistical mission and taught It has not been optimized to find excellent individual planets for further investigation, but now that we know that planets are in widespread use, we can launch something like TESS to look for the planets we have Investigate intensively with ground-based and space-based telescopes, planets that TESS will find will be 10x nearer and 100x brighter on average. "

For their In the study, the team created a three-tier model that considered the stars that TESS will observe, the number of planets is likely, and the likelihood that TESS will detect them. These included the types of planets circling around dwarf stars ranging from A-type to K-type (like our Sun) and M-type stars (red dwarf) of lower mass.

"To estimate how many planets TESS will find we've taken stars that are observed by TESS and simulate a population of planets orbiting them," Barclay said. "The population data from the exoplanets are all from studies using Kepler data, and we used models of TESS performance to estimate how many of these planets would be detected by TESS, and that's how we get our numbers."

The The first step, thanks to the availability of the Candidate List (CTL) – a prioritized list of target stars identified by the TESS Target Selection Working Group – was the easiest star to detect small planets. Then they ranked the 3.8 million stars included in the latest version based on their brightness and radius, and determined which of these TESSs will likely be observed.

Launch of spacecraft SpaceX Falcon 9 with NASA spacecraft TESS. Photo credits: NASA TV

The second step was to assign planets to each star based on a Poisson distribution, a statistical technique in which each star (in this case, 0 or more) is assigned a specific number. Each planet was then assigned six randomly drawn physical properties, including orbital period, radius, eccentricity, Periastron angle, slope to our line of sight, and mean time of the first pass.

Lastly, she tried to estimate how many of these planets would produce a detectable transit signal. As already mentioned, TESS will rely on the transit method, which uses periodic dips in the brightness of a star to determine the presence of one or more planets in orbit, as well as limitations on their size and orbital times. To do so, they considered the flux contamination of near stars, the number of transits and the transit time.

Eventually, they found with 90% certainty that TESS will likely discover 4430-4660 new exoplanets during their two-year mission:

"The result is that we predict that TESS will find more than 4000 planets Hundreds less than twice the Earth The primary goal of TESS is to find planets bright enough for the ground-based telescope to measure their mass. We estimate that TESS is the number of planets smaller than the Earth 4 Earth's radii could triple with mass measurements. "

As of April 1, 2018, a total of 3,758 exoplanets were confirmed in 2,808 systems, with 627 systems more than one planet. In other words, Barclay and his team estimate that the TESS mission will double the number of confirmed exoplanets and triple the number of Earth and Super Earth satellites during their primary mission.

This will begin after a series of orbital maneuvers and technical tests, which are expected to take about two months. With the expanded Exoplanet catalog, we can expect that there will be many more "earth-like" candidates for study. And although we still can not determine if any of them have any life, we may find some that show signs of a viable atmosphere and water on the surfaces.

The hunt for life beyond the earth will take many more years Come! And in the meantime, enjoy this video about the TESS mission courtesy of NASA:

Further reading: Astrobites arXiv

Extra Solar Planets, Featured, Hubble Space Telescope, James Webb Space Telescope, Kepler Space Telescope, TESS, Transit Exoplanet Surveying Satellite




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