An unknown, unseen “planetary mass object” may lurk in the outer reaches of our solar system, according to new research on the orbits of minor planets to be published in the Astronomical Journal. This object would be different from — and much closer than — the so-called Planet Nine, a planet whose existence yet awaits confirmation.
Cool dwarf stars are hot targets for exoplanet hunting right now. The discoveries of planets in the habitable zones of the TRAPPIST-1 and LHS 1140 systems, for example, suggest that Earth-sized worlds might circle billions of red dwarf stars, the most common type of star in our galaxy. But, like our own sun, many of these stars erupt with intense flares. Are red dwarfs really as friendly to life as they appear, or do these flares make the surfaces of any orbiting planets inhospitable?
A newly discovered Jupiter-like world is so hot, it’s being vaporized by its own star. With a dayside temperature of more than 7,800 degrees Fahrenheit, KELT-9b is a planet that is hotter than most stars. But its blue A-type star, called KELT-9, is even hotter — in fact, it is probably unraveling the planet through evaporation.