Hot Jupiters are giant exoplanets – even more massive than Jupiter – but they orbit closer to their star than Mercury. When they were first discovered, hot Jupiters were considered oddballs, since we don’t have anything like them in our own Solar System. But they appear to be common in our galaxy. As exoplanets go, they are fairly easy to detect, but because we don’t have up-close experience with them, there are still many unknowns.
A new study used archival data from the Hubble and Spitzer space telescopes to study this class of giant gas exoplanets, and undertook one of the largest surveys ever of exoplanet atmospheres. The researchers said they employed high performance computers to analyses the atmospheres of 25 hot Jupiters using data from about 1,000 hours of telescope observations. Their findings, published in the Astrophysical Journal Supplement Series, help to answer several long-standing questions about hot Jupiters.
Among the thousands of known exoplanets, there are some that are very odd. Take, for example, the exoplanet known as WASP-103b. It’s a large planet with a mass about 1.5 times that of Jupiter, but 103b is so close to its star it makes a complete orbit every 22 hours. At this proximity, many astronomers wonder if the world is on the edge of being ripped apart by tidal forces. But a new study shows us that something much more interesting is going on.
Most exoplanets are found using a technique known as the transit method, where the exoplanet passes in front of its star, causing the star to dim slightly. It takes several transits to confirm an exoplanet, so it’s not surprising that most known exoplanets have a fairly short orbital period. Months or days rather than years. There’s also an observational bias in that most known stars are red dwarfs, so it’s usually not surprising that we’ve found yet another exoplanet closely orbiting a red dwarf star. But sometimes what we find is so extreme, it really is surprising.
The Colorado Ultraviolet Transit Experiment (aptly nicknamed CUTE) is a new, NASA-funded mission that aims to study the atmospheres of massive, superheated exoplanets – known as hot Jupiters – around distant stars. The miniaturized satellite, built by the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, is set to launch this Monday, September 27th on an Atlas V rocket.
Researchers at the Flatiron Institute’s Center for Computational Astrophysics published a paper last week that just might explain a mysterious gap in planet sizes beyond our solar system. Planets between 1.5 and 2 times Earth’s radius are strikingly rare. This new research suggests that the reason might be because planets slightly larger than this, called mini-Neptunes, lose their atmospheres over time, shrinking to become ‘super-Earths’ only slightly larger than our home planet. These changing planets only briefly have a radius the right size to fill the gap, quickly shrinking beyond it. The implication for planetary science is exciting, as it affirms that planets are not static objects, but evolving and dynamic worlds.
The molecule hydroxyl (HO) is common on Earth, but astronomers have not yet determined how abundant it is on other worlds. For the first time, astronomers have conclusively detected it in the atmosphere of an ultra-hot Jupiter, WASP-33b.
The search for exoplanets has revealed types of planets that are nothing like the worlds in our own Solar System. One such type is the hot-Jupiter. They’re gas giants like Jupiter that orbit their host star very closely. That proximity raises their temperatures to extreme heights.
Hot-Jupiters can be hot enough to vaporize metals, making their atmospheres un-Earthlike. A team of astronomers examining one exoplanet has found 7 different gaseous metals in its atmosphere.
The discovery of over 4000 planets (4,171 confirmed and counting!) beyond our Solar System has revolutionized the field of astronomy. Unfortunately, one of the downsides of all these discoveries is how it has shaken up theories about how our Solar System formed. In the past, astronomers thought that the eight planets (or nine, or over one hundred, depending on your point of view) formed where they are currently located.
However, the discovery of gas giants that orbit close to their stars (aka. “Hot Jupiters”) has confounded this thinking. But according to a recent NASA-supported study, the recent discovery of a young gas giant could offer clues as to how Jupiter-like planets form and whether or not they migrate. This discovery was made possible thanks to the Spitzer Space Telescope, which continues to reveal things about our Universe even in retirement.
Thanks to the success of the Kepler mission, we know that there are multitudes of exoplanets of a type called “Hot Jupiters.” These are gas giants that orbit so close to their stars that they reach extremely high temperatures. They also have exotic atmospheres, and those atmospheres contain a lot of strangeness, like clouds made of aluminum oxide, and titanium rain.
A team of astronomers has created a cloud atlas for Hot Jupiters, detailing which type of clouds and atmospheres we’ll see when we observe different Hot Jupiters.