Two new "hot Jupiter" exoplanets have been discovered by a team of Chilean astronomers through the analysis of data gathered from NASA's Kepler spacecraft during its K2 mission profile. The planets - EPIC210957318b and EPIC212110888b - are gas giants that possess many similar characteristics as Jupiter, the solar system's biggest planet, and possess orbital periods of less than 10 days.
Approximately 250 transiting hot Jupiter exoplanets have been found to date, with most of the discoveries stemming from ground-based photometric surveys. However, the two new findings were made using a space telescope, which shows the potential for using such technology to detect massive new exoworlds.
Using photometric data from two of K2's observation campaigns, the team discovered that both stars exhibited strong periodic signals - every four and three days, respectively.
"Both of these systems were selected as strong Jovian planetary candidates based on their transit properties (depths, shapes and durations), and due to the lack of evident out of transit variations," the authors wrote.
After observing these findings, the team took advantage of three separate stabilized spectrographs on La Silla Observatory telescopes in order to acquire high-resolution spectra of the two massive exoplanets. These telescopes were of particular use for their ability to analyze the radial velocity variation of the exoplanets stemming from the gravitational pull generated by orbiting planets.
The smaller of the two planets, EPIC210957318b, is located approximately 970 light years from the Earth and orbits a parent star that is much like our sun. The orbit takes place every 4.1 days, and the exoplanet possesses a mass that lies somewhere between Saturn and Jupiter, with the team approximating its size as around 0.65 Jupiter masses.
Conversely, EPIC212110888b possesses a mass around 1.63 times that of Jupiter and orbits its host star every three days. It is slightly more massive than the sun and lies approximately 1,270 light years away from Earth.
The team believes that both planets are candidates for follow-up studies and possess orbital and physical properties typical of known hot Jupiters.
"The low density of EPIC210957318b combined with the relatively small radius of its host star implies a scale height of 340 kilometers and a transmission spectroscopic signal of 744 parts-per-million (assuming a hydrogen gas-dominated atmosphere and a signal of five scale-heights), which means that this system is a good target to be observed via transmission spectroscopy to characterize its atmosphere," the team concluded.
The findings were released on March 5 on the arXiv server.
