Just this month NASA's TESS the Transiting Exoplanet Survey Satellite has completed its first mission. Moving forward Tess will continue orbiting the earth while gathering new information about new planets located in other star systems. To date Tess has already confirmed 131 planets with another 4,195 planet candidates awaiting secondary ground-based telescope observations. TESS is NASA's newest looking glass with a goal to scan %75 of the night sky for signs of exoplanets that orbit other stars.
TESS studies the light signatures of other stars looking for dimming events that are called transits. These events happen when other planets pass in front of their host stars in respect to our point of view. After the completion of the first two-year survey TESS still has much planet-hunting power left. TESS will become an extended planet-hunting mission which NASA hopes will find many new incredible discoveries. In the primary mission, TESS will briefly map the starlight of each star sector in 30-day observations until 75% of the visible sky from the earth's point of view is covered.
The mission's data is divided into many segments as TESS rotates its view of the universe. Some of these segments, depending on sector location will have more time-series data available than others.
TESS started by mapping the southern skies and once completed the telescope moved on to map northern skies. Now TESS will once again flip its perspective to study the southern skies more in-depth. As part of the second mission, TESS will take a light sample from each target in view every ten minutes providing more details about each star. Previously light data points were binned at higher intervals, and this new improvement will allow us to study variable stars which pulsate and flare. These detailed observations will reveal many new details about exotic star types. As a prelude to TESS, NASA's Kepler Mission discovered an entirely new class of Binary Stars entitled "Heartbeat Binaries" due to the distinct way this class's starlight was captured by Kepler's photometer and displayed beautifully showing a heartbeat-like pattern.
Delta Scuti Stars as shown below have also been studied by prior planet-hunting missions like Kepler. Delta Scuti stars provide a wonderfully artistic display when light data points are transferred onto data graphs. These studies reveal each star's periodic variability and internal mechanics.
NASA plans to utilize the new ability to capture starlight data at ten-minute intervals to study exotic pulsating stars. TESS is scheduled to complete a 15-month survey of the southern skies and then begin another along the ecliptic plane of TESS's orbit around the sun. TESS will continue to study many new worlds and exotic star systems for years to come.
Detections of exoplanets orbiting other star systems is actually a rather new field of study. The very first extrasolar planetary detection was confirmed in 1992 when radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of a planet orbiting the pulsar star PSR 1257+12. Follow-up observations confirmed this discovery. Today we know there are three planets in this star system. Amazingly these planets are believed to have formed from the remnants of a supernova, in the second round of planetary formation. One theory suggests these planets are the rocky cores of gas giants that survived the supernova event and have now settled into current orbits.
The second exoplanetary confirmation happened roughly 30 years ago with the detection of a giant planet orbiting every 4.2 days around a nearby main-sequence star known as Pegasi 51. This discovery by Michel Mayor and Didier Queloz of the University of Geneva who them a Nobel Prize in Physics. Such efforts are thought to have ushered in the modern era of planet-hunting.
In 1999 Upsilon Andromedae won the title of being the first even known main-sequence star with multiple planets. Located 44 light-years from the earth this system is actually a Binary Star with an F Type Maine sequence star orbited by a smaller red dwarf star. Today we know Upsilon Andromedae has four planets b, c, d, and e. It was not only the first-ever known main-sequence star discovered with multiple planets but also the first-ever binary star discovered with multiple planets!
Today the James Webb telescope is also being built with the ability to study the atmospheric compositions of these planets while finding new ones. The James Webb telescope is scheduled to be launched in 2021; it will be the most powerful and complex space telescope ever launched into space.