When the first hot Jupiters were detected about a generation ago, they were generally thought to be “oddballs” because we do not have anything like them in our own Solar System. However, as more and more of these bizarre, exotic, and puffed-up giant worlds were spotted over the last two decades, in orbit around distant stars beyond our own Sun, it began to look like our own Solar System is the true oddity.
Ever since the historic discovery of the first exoplanet in orbit around a Sun-like star, back in 1995, planet-hunting astronomers have been detecting a previously unknown, and well-hidden, treasure trove of weird, wild, and wonderful distant worlds. Some of these remote planets display an almost eerie similarity to the familiar planets inhabiting our own Solar System–while others are so exotic that their existence in nature both surprised and baffled their discoverers.
Hot Jupiters hug their parent-stars so closely that a “year” for them lasts only a few days. One of the most famous hot Jupiters, 51 Pegasi b, discovered in 1995, was the first exoplanet to be discovered circling a main-sequence (hydrogen-burning) star on the Hertzsprung-Russell Diagram of Stellar Evolution. 51 Pegasi b has an orbital period of about 4 days. This initial discovery of a hot Jupiter proved to be a surprise for planet-hunting astronomers who did not think that such close-in, giant, gas-laden worlds could really exist in nature. The mystery surrounding the formation of this very alien form of exoplanet has plagued the astronomical community for more than twenty years.
Even though the discovery of literally thousands of exoplanets has now become “business as usual” for astronomers on the hunt for these remote worlds, this has not always been the case. Indeed, the search for planets belonging to the families of stars beyond our own Sun, historically proved to be extremely challenging–as well as frustrating. At last, back in 1992, the first batch of truly weird exoplanets to be validated were detected in orbit around a very small, dense, and rapidly spinning stellar corpse termed a pulsar. Dr. Alexander Wolszczan of Pennsylvania State University, after carefully observing radio emissions flowing out from a compact millisecond pulsar with the unexciting name of PSR B1257 +12, made the determination that it was being circled by several very exotic little worlds. A pulsar is only about 12 miles in diameter–and it is really the collapsed core of what was once a massive main-sequence star. This strange, dense, and tiny stellar “oddball” is all that is left of a star that has finished burning its necessary supply of hydrogen fuel, and has “died” in the horrific, brilliant, and explosive tantrum of a supernova blast.
51 Pegasi b was discovered three years later by Dr. Michel Mayor and Dr. Didier Queloz of Switzerland’s Geneva Observatory. This discovery was quickly confirmed by a team of American planet-hunting astronomers using the Lick Observatory’s three-meter telescope poised at the summit of Mount Hamilton in California.
Of course, new theories were proposed to explain these “oddball’ hot Jupiters. Some astronomers suggested that these “roasters” were really enormous molten rocks; while still others proposed that they were gas-giant planets that had been born about 100 times further away from their parent-stars. According to this latter theory, hot Jupiters were ruthlessly thrown about 100 times closer to their stellar parents as a result of near-collisions with other sibling worlds. Alternatively, a binary stellar companion of their host star may have been the culprit behind this tragic kick towards their fiery, roiling stellar parent.
One theory put forward suggests that hot Jupiters are born at a distance from their star that is approximately the same as that of our own Solar System’s banded behemoth, Jupiter’s, distance from our Sun. Alas, these ill-fated giant worlds slowly lose energy as a result of their unfortunate dance with the protoplanetary accretion disk, which is a disk of gas and dust surrounding their parent-star, from which planets eventually emerge. The newborn giant planet, as a result, spirals into the well-lit and seething-hot inner regions of its planetary system, coming in from its much colder and very remote place of birth.
Hot Jupiters are likely doomed giants, destined to come to a final, fiery, and truly miserable end within the furious furnaces of their glaring parent-stars. However, until that final, fatal moment, these very unfortunate “roasters” orbit their host stars fast and close.
These puffy “roasters” are actually a mixed bag, displaying some diversity in their attributes. However, these exoplanets do share certain characteristics. All hot Jupiters have very low densities, large masses, brief orbital periods around their parent-stars, and almost circular orbits. Hot Jupiters also are likely to possess extreme and exotic atmospheres because of their brief orbital periods, relatively long days, and tidal locking. mkvmoviesking