Based on the catalog of simulated TESS detections by Sullivan et al. (2015), we determine appropriate cutoff values of the metrics, such that the TESS mission will ultimately yield a sample of ∼300 high-quality atmospheric characterization targets across a range of planet size bins, extending down to Earth-size, potentially habitable worlds.
Because it’s looking at bright stars, this means it’s looking for the most part at nearby stars. An exoplanet it just found fits that bill: At just over 22 light years distant, it’s the second nearest transiting exoplanet seen*, and the closest to the Sun detected so far orbiting a tiny red dwarf!But this story just gets better. The star is part of a triple system of red dwarfs.
But we do know more about it. Observations using an instrument called HARPS were used to determine the mass of the planet, and it turns out to have at most 8.4 times Earth’s mass. A statistical analysis found a likely mass of 2.2 times Earth’s. That’s interesting, because that means it would have a density of about 90% Earth… which in turn means it’s made of slightly, but only slightly, less heavy stuff. Maybe it has a smaller iron core, or less rock and more water in the mantle and crust. These numbers are iffy, so this is just speculation. But it seems likely it’s a terrestrial planet, with at least a passing resemblance to Venus and Earth. Given the surface temperature, more like the former than the latter.
But in recently published research, a team of astronomers at The Ohio State University showed that the survey, nicknamed TESS, could also be used to monitor a particular type of supernova, giving scientists more clues about what causes white dwarf stars to explode—and about the elements those explosions leave behind."We have known for years that these stars explode, but we have terrible ideas of why they explode," said Patrick Vallely, lead author of the study and an Ohio State astronomy graduate student. "The big thing here is that we are able to show that this supernova isn't consistent with having a white dwarf (take mass) directly from a standard star companion and explode into it—the kind of standard idea that had led to people trying to find hydrogen signatures in the first place. That is, because the TESS light curve doesn't show any evidence of the explosion slamming into the surface of a companion, and because the hydrogen signatures in the SALT spectra don't evolve like the other elements, we can rule out that standard model."
Three newly discovered exoplanets could help researchers redefine the shaky line between rocky and gaseous planets, according to new observations from NASA’s Transiting Exoplanet Survey Satellite (TESS). TESS, which marks its first year of operations this month, spotted the trio of planets some 73 light-years away from Earth. The exoplanets are of a type that does not exist in our solar system, being between the Earth and Neptune in size.That makes the closely packed system, known as TOI-270, a good bet for answering long-standing questions about how such “super-Earths” or “mini-Neptunes” form. The system is within range of ground-based telescopes and soon-to-be-launched orbiting instruments such as NASA’s James Webb Space Telescope (JWST). “This will be one of the key systems for JWST to study,” says Michaël Gillon of the University of Liège in Belgium, who is following up on the TESS discovery.
Confirmation of Toasty TESS Planet Leads to Surprising Find of Promising World“If the planet has a dense atmosphere, which will take future studies to determine, it could trap enough heat to warm the planet and allow liquid water on its surface.”
what technology do we have now that will allow us to confirm a dense atmosphere and/or water on an exoplanet ??
NASA's Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star's habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA's Spitzer Space Telescope and have modeled the planet's potential environments to help inform future observations.
TESS has begun its extended mission, focusing on the Southern Hemisphere but also more on the ecliptic.I seem to remember there had been numerous options for missions extensions considered but can't recall the details.