Hot Jupiter exoplanets are huge gas-giant worlds akin to our own Solar System’s Jupiter. Unlike our Jupiter, however, hot Jupiters don’t live in the cooler outer regions of their planetary systems, but rather hug their searing-hot, fiery, glaring parent celebrities quickly and close in”roasting” orbits. In September 2014, a group of planet-hunting astronomers announced their discovery of yet another bizarre alien planetary system, in which a fascinating duo of Jupiter-sized exoplanets are observed–every orbiting a distinct leading twin of a binary-star system.
The majority of the known exoplanets circle solitary stars, like our own lonely Sun. But many stars are members of binary systems–twin stars that were born from the exact natal cloud of dust and gas. Now, for the first time, two twin stars composing a binary system are both seen to sponsor a sexy Jupiter exoplanet.
The bizarre discoveries, circling the stellar sisters WASP-94A and WASP-94B, were made by a team of British, Belgian, and Swiss astronomers.
A new survey, known as the WASP-South survey, led by astronomers from Keele University in Staffordshire, UK, found small dips in the light emanating from WASP-94A, indicating a planet like Jupiter was passing in front of (transiting) the fiery, brilliant surface of its parent-star. Swiss astronomers then demonstrated the presence of planets circling both WASP-94A and then its twin stellar sister WASP-94B. Dr. Marion Neveu-VanMalle of Geneva University in Switzerland, who wrote the statement paper, commented at a September 30, 2014 University of Keele Press Release that”We observed the other star by accident, and found a planet around that one too!”
Hot Jupiters hug their stellar parents carefully, circling them in hellish orbits–with a”year” lasting only a couple of days. However, hot Jupiters are in fact rare denizens of the planetary zoo–thus making it extremely improbable that two hot Jupiters would be spotted by chance, inhabiting the identical stellar system. Maybe WASP-94 is unique, and just happens to have the correct conditions for giving birth to these rare sexy Jupiter exoplanets? If this turns out to be true, WASP-94 might be a crucial method for understanding why hot Jupiters somehow manage to circle their leading parents in such fast, close, and”roasting” orbits.
The presence of these enormous, gaseous Jupiter-like exoplanets, orbiting so close to their stars, has presented a long-standing mystery. This is because gas-giant planets cannot be born hugging their parent-stars–it is much too hot there for them to form.
The very first exoplanet to be discovered orbiting a main-sequence (hydrogen burning) Sun-like celebrity proved to be a hot Jupiter. This discovery shocked planet-hunting astronomers who did not think that such close-in, giant, gaseous worlds could exist. This puzzle has plagued the planetary science community for the last twenty years.
An exoplanet is an alien world that doesn’t orbit our Solar System’s Sun, but rather circles a distant, different star, stellar remnant, or brown dwarf (failed star). As of September 29, 2014, more than 1800 exoplanets have been detected–with 1822 planets dwelling in 1137 planetary systems, including 467 multiple planetary systems. In addition, you will find free-floating”orphan” planets that are not gravitationally bound to any star in any way, but float through interstellar space, tragically bereft of the companionship of a stellar parent or planetary siblings of their own. After, these gloomy planetary”orphans” were part of a system, but they were likely cruelly evicted from the gravitational bullying of sister planets which hurled them in the cold, dark space between stars.
The highly effective Kepler Space Telescope has spotted a few thousand potential exoplanets, of which about 11% might prove to be false-positives. Planetary scientists estimate that there are likely, in the very least, 1 planet on average per celebrity dwelling in our starlit, spiral Milky Way Galaxy. Maybe 1 in 5 stars like our own Sun sport an”Earth-sized” planet in the habitable zone. The habitable zone surrounding a star is that comfortable”Goldilocks” region where the temperatures are”just right” for water to exist in its life-sustaining liquid stage. Where liquid water exists, Bat Poop as we understand it can also possibly exist.
Even though the discovery of so many alien worlds has become almost commonplace–“business as usual” for planet-hunting astronomers–that has not always been the case. In actuality, the hunt for planets beyond our own Solar System historically been shown to be a rather frustrating, difficult, and long pursuit. Finally, back in 1992, the very first batch of eccentric exoplanets were successfully seen in orbit around a compact, small, wildly spinning stellar relic known as a pulsar. Dr. Alexander Wolszczan of Pennsylvania State University, after carefully analyzing radio emissions coming from a compact millisecond pulsar, called PSR B1257+12, determined that it was being circled by several very bizarre planets. A pulsar is a small oddball of about 12 miles, therefore, in diameter. It is actually the collapsed core of what was once a enormous main-sequence star that, after having burnt its mandatory supply of hydrogen gas, blew itself to smithereens in the fiery anger of a supernova blast.
The historical discovery was made by Dr. Michel Mayor and Dr. Didier Queloz of Switzerland’s Geneva Observatory.
This hot-Jupiter world, that clung closely to its searing-hot parent star, was the first of its baffling type to bewilder astronomers. 51 Peg b, which orbits its star 51 Pegasi every 4.2 days, is a mere 4,300,000 miles from its stellar parent. However, the existing theories of planet formation with that era indicated that giant Jupiter-like planets could only be born at substantially greater distances from their stars. So, what was the enormous, gaseous 51 Peg b doing orbiting its star in such a close-in orbit?
51 Peg b proved to be only the tip of the iceberg–it was the first discovery of an entirely new and unforeseen class of exoplanets. Ever since the discovery of 51 Peg b twenty years back, many other hot Jupiters have been discovered by planet-hunting astronomers looking for distant worlds beyond our own Sun’s family.
New theories were invented to describe hot Jupiters. Some astronomers thought that these”roasters” were basically huge molten rocks; while others suggested that they were gas-giant planets which were really born 100 times further away from their stars–and were shot back towards their parent-star as a result of near-collisions with other sister planets, or maybe even a companion star of their very own stellar parent.
One theory suggests that hot Jupiters are born at a distance like Jupiter’s average distance from our Sun, then gradually lose energy as a result of interactions with the disc of gas and dust (protoplanetary accretion disc ) where they had formed. The newborn giant planet, therefore, spirals to the warm inner regions of its planetary system from its more distant birthplace.
Hot Jupiters may be tragedies in the making, doomed to crash into a fiery death within the raging furnaces of their seething-hot parent-stars. Until that time, however, these unfortunate”roasters” orbit their stars fast and close, in their hell-like orbits.
Hot Jupiter planets have to be born much further out in their systems, where the temperatures are sufficiently cold for ices to freeze out of the protoplanetary disc swirling around the young star–thus forming a new baby world. Something must then occur that moves the planet into a close-in,”roasting” orbit, and one possible mechanism is an interaction with another sister planet or star. Spotting sexy Jupiter planets circling around two sister celebrities composing a binary pair might permit astronomers to study the still-mysterious procedures that move the hot Jupiters inward.
The two stars are rather bright, making it effortless to study their planets, so WASP-94 could be used to detect the compositions of the atmospheres of the exoplanets.”
The WASP survey is the most prosperous hunt for hot Jupiter exoplanets which transit–or float in front of–the glaring face of the parent-stars. The WASP-South survey instrument searches the sky every clear night, scanning literally thousands and thousands of sparkling stars for transits.