NASAs TESS celebrates fifth year scanning th – EurekAlert

Now in its fifth year in space, NASAs TESS (Transiting Exoplanet Survey Satellite) remains a rousing success. TESSs cameras have mapped more than 93% of the entire sky, discovered 329 new worlds and thousands more candidates, and provided new insights into a wide array of cosmic phenomena, from stellar pulsations and exploding stars to supermassive black holes.

Using its four cameras, TESS monitors large swaths of the sky called sectors for about a month at a time. Each sector measures 24 by 96 degrees, about as wide as a persons hand at arms length and stretching from the horizon to the zenith. The cameras capture a total of 192 million pixels in each full-frame image. During its primary mission, TESS captured one of these images every 30 minutes, but this torrent of data has increased with time. The cameras now record each sector every 200 seconds.

The volume of high-quality TESS data now available is quite impressive, said Knicole Coln, the missions project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. We have more than 251 terabytes just for one of the main data products, called full-frame images. Thats the equivalent of streaming 167,000 movies in full HD.

TESS extracts parts of each full-frame image to make cutouts around specific cosmic objects more than 467,000 of them at the moment and together they create a detailed record of changing brightness for each one, said Christina Hedges, lead for the TESS General Investigator Office and a research scientist at both the University of Maryland, Baltimore County and Goddard. We use these files to produce light curves, a product that graphically shows how a sources brightness alters over time.

To find exoplanets, or worlds beyond our solar system, TESS looks for the telltale dimming of a star caused when an orbiting planet passes in front of it. But stars also change brightness for other reasons: exploding as supernovae, erupting in sudden flares, dark star spots on their rotating surfaces, and even slight changes due to oscillations driven by internal sound waves. The rapid, regular observations from TESS enable more detailed study of these phenomena.

Some stars give TESS a trifecta of brightness-changing behavior. One example is AU Microscopii, thought to be about 25 million years old a rowdy youngster less than 1% the age of our Sun. Spotted regions on AU Mics surface grow and shrink, and the stars rotation carries them into and out of sight. The stormy star also erupts with frequent flares. With all this going on, TESS, with the help of NASAs now-retired Spitzer Space Telescope, discovered a planet about four times Earths size orbiting the star every 8.5 days. Then, in 2022, scientists announced that TESS data revealed the presence of another, smaller world, one almost three times Earths size and orbiting every 18.9 days. These discoveries have made the system a touchstone for understanding how stars and planets form and evolve.

Here are a few more of the missions greatest hits:

New discoveries are waiting to be made within the huge volume of data TESS has already captured. This is a library of observations astronomers will explore for years, but theres much more to come.

Were celebrating TESSs fifth anniversary at work and wishing it many happy returns! Coln said.

TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASAs Ames Research Center in Californias Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MITs Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes, and observatories worldwide are participants in the mission.

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