After the Kepler mission endured some serious difficulties this summer and the full recovery failed, astronomers were forced to change the primary purpose of this famous space observatory. Despite some doubts about the future viability of the project, the Kepler team is even going to make new scientific discoveries. And their goal is rather serious: the team is planning to conduct the search for an entirely new class of exoplanets.

What are those mysterious planets? These objects are approximately Earth-sized exoplanets with one main difference: their orbital period is equal to or even shorter than one day. Yes, this is really a very short duration for any planet-like entity orbiting a star: it is enough to imagine one year flying by in less than 24 hours…

Meanwhile, Brian Jackson from Carnegie Institution for Science in Washington published a paper on arXiv.org, in which he explains this idea. Apparently, the previous astronomical surveys made by Kepler identified more than ten potential exoplanets with very-short orbital period, and it seems that the current remaining functional capabilities of this space observatory are sufficient to accomplish this task.

According to the author, this project could provide some new insights about planets’ formation and evolution, including the new observations of the interactions between planets and stars, or between planets and stellar wind. The evolution of these exoplanets may differ from the planets in our Solar system.

The planets that are located within the radius of 0.1 astronomical unit of their home stars, are not uncommon: there is a large number of identified exoplanets that meet this condition. For example, the Kepler-78b (orbiting the star KIC 8435766) has an orbital period of about 0.355 days or 8.5 hours. Its distance from the star is only three times larger than the radius of the host star, and it is 40 times smaller compared to Mercury’s distance from the Sun. This means, that surface temperature on the Kepler-78b day side may reach ~2,300K and the planet may even contain an atmosphere from rock vapours. It is obvious that more detailed analysis of these planets could provide a lot of valuable information about their chemical composition, and, of course, their origin.

Certainly, the current Kepler’s capabilities are very limited; however, Brian Jackson argues, that this instrument could prove its usefulness by performing a preliminary survey of very short orbital period planets.

By Alius Noreika, Source: Technology.org