Kepler takes in a haul of over 100 exoplanets
Using data collected by the KeplerSpace Telescope alongside a number of Earth-bound observatories, aninternational team of astronomers has confirmed the existence of overa hundred previously unknown exoplanets discovered in the directionof the Aquarius constellation. Among the throng of newlydiscovered worlds, two potentially habitable exoplanets have beenidentified orbiting a distant dwarf star.
The Kepler Space Telescope has beenresponsible for the confirmed discovery of almost 2,500 exoplanetssince its launch from Cape Canaveral in 2009. Kepler's primarymission was terminated when the loss of a second reaction wheel stripped the telescope of itsability to precisely fix its position in space.
However,engineers were able to develop a system for steadying the telescope that made use of the pressure exerted by sunlight to compensate forthe damaged reaction wheel, allowing it to once again carry out itspurpose.
Havingbeen saved from an early retirement, the resurrected Keplerbegan its K2 mission in June 2014. K2 has beenresponsible for the discovery of hundreds more exoplanets that haverevolutionized our understanding of distant solar systems and howthey came to form.
The initial discovery of the mostrecent batch of exoplanets was made by Kepler as it patiently watchedfor the periodic dimming in the light signature of one of the many M dwarf (also known as red dwarf) stars that fell under its gaze known as K2-72. This dimming is created as anexoplanet passes across a star's surface, blocking a portion of its light.
Follow-up observations were thencarried out by numerous terrestrial telescopes, which captured high-resolution data and spectrographic readings on the planets, allowingthe team to confirm 104 exoplanets out of a possible 197 candidatebodies.
All of the exoplanets discovered in theeffort are estimated to be around 20 to 50 percent larger than ourplanet by diameter. The vast majority of the worlds were deemed to betoo hostile for the creation and evolution of life. However,astronomers did identify four rocky planets orbiting K2-72, two of which mayposses the vital characteristics for harboring life.
K2-72 is situated roughly 181 lightyears from Earth in roughly the same region as the constellationAquarius. Two of the rocky planets in orbit around the star areconsidered to be too hot to be viable candidates for the developmentof extraterrestrial life. However, the two remaining worldsare thought to orbit within the red dwarf's habitable zone.
Onaverage, red dwarfs such as K2-72 are significantly dimmer, and lessthan half of the diameter of our own Sun. Because of this, theirhabitable zone — the region in which a planet can orbit its star andmaintain liquid water on its surface — occupies an area much closer to a red dwarf's surface.
K2-72c,which is thought to be the innermost of the two potentially habitableplanets, is estimated to be around 10 percent warmer than Earth, andcompletes a circuit of its parent star once every 15 Earth days.K2-72e, which is believed to traverse a more distant orbit, isroughly 6 percent colder than our planet, and has a more leisurely 24-day yearly cycle.
According to the team, it is possiblefor life to arise on rocky planets such as K2-72c and K2-72e eventhough they orbit a cool red dwarf star. A recent discovery suggeststhat tidally locked exoplanets, which make up themajority of the worlds detected in orbit around red dwarfs, could berendered habitable by a form of atmospheric climate control process. This revelationpaired with the prevalence of red dwarf stars will make them anattractive target for the next generation of terrestrial and spacebound telescopes.