The radii Rp and periods P of KELT-16 b, along with lots of other short-period planets. From Oberst et al. (2017).

There’s a new paper from the KELT Survey and led by Prof. Thomas Oberst from Westminster College announcing the discovery of another exoplanet in a very small orbit, nearly skimming the surface of its host star: KELT-16 b is a highly irradiated, ultra-short period hot Jupiter nearing tidal disruption.

These planets have been something of a puzzle since the first was discovered back in 1995. Like Jupiter, they are mostly made out of hydrogen and helium gas, but unlike Jupiter, they orbit very close to their host star, which probably means they didn’t form where we see them today.

Even among hot Jupiters, though, KELT-16 b is an outlier. It’s one of a handful of hot Jupiters with orbital periods less than 1 day (as compared to Jupiter’s orbital period of 12 years), so whatever processes led to its origin are cranked up to 11 for KELT-16 b and its ultra-short period siblings.

The mystery of its origins aside, its short period means KELT-16 b is probably a good candidate for follow-up observations of its atmosphere, particularly by the James Webb Space Telescope. But tidal interactions with its host star means it may get eaten by its host star in less than a million years, so we need to get those observing proposals submitted soon.