Jupiter is well known for its spectacular aurorae, thanks in no small part to the Juno orbiter and recent images taken by the James Webb Space Telescope (JWST). Like Earth, these dazzling displays result from charged solar particles interacting with Jupiter’s magnetic field and atmosphere. Over the years, astronomers have also detected faint aurorae in the atmospheres of Jupiter’s largest moons (aka. the “Galilean Moons“). These are also the result of interaction, in this case, between Jupiter’s magnetic field and particles emanating from the moons’ atmospheres.
Detecting these faint aurorae has always been a challenge because of sunlight reflected from the moons’ surfaces completely washes out their light signatures. In a series of recent papers, a team led by the University of Boston and Caltech (with support from NASA) observed the Galilean Moons as they passed into Jupiter’s shadow. These observations revealed that Io, Europa, Ganymede, and Callisto all experience oxygen-aurorae in their atmospheres. Moreover, these aurorae are deep red and almost 15 times brighter than the familiar green patterns we see on Earth.
Planetary scientists have greatly anticipated using the James Webb Space Telescope’s infrared vision to study Saturn’s enigmatic moon Titan and its atmosphere. The wait is finally over and the results are spectacular. Plus, JWST had a little help from one of its ground-based observatory friends in helping to decode some strange features in the new images. Turns out, JWST had just imaged a rare event on Titan: clouds.
Gravity is a funny force. The gravity of every given object technically impacts every other given object, though, in practice, large distance and small masses make those forces negligible for such interactions. But in some cases, especially when large groups are floating in empty space, gravity can still hold sway over considerable distances. Such is the case with a new pair of brown dwarfs found by astronomers at the Keck Observatory.
Astronomers have spied three more exoplanets. But the discovery might not last long. Each planet is in a separate solar system, and each orbits perilously close to its star. Even worse, all of the stars are dying.
For the first time, a team of astronomers have imaged in real-time as a red supergiant star reached the end of its life. They watched as the star convulsed in its death throes before finally exploding as a supernova.
And their observations contradict previous thinking into how red supergiants behave before they blow up.
Sometimes loud explosions are easier to deal with when you know they’re coming. They are also easier to watch out for. So when astronomers from the University of Warwick found a rare tear-drop shaped star, known as HD265435, they knew they were looking at a potential new supernova waiting to happen. The only caveat – it might not actually happen until 70 million years from now.
One of the unspoken caveats of most exoplanet discovery missions is that they only operate for a few years. Such a short observing window means there are planets with longer orbital periods, usually further out from the star, that those surveys would completely miss. Knowing this would be a problem, a team of astronomers arranged the California Legacy Survey three decades ago in order to monitor as many stars as possible for as long a time as possible. Recently they released their first results, which show solar systems that are surprisingly like our own.
Planet formation is a notoriously difficult thing to observe. Nascent planets are ensconced inside dusty wombs that resist our best observation efforts. But recently, astronomers have made progress in imaging these planetary newborns.
A new study presents the first-ever direct images of twin baby planets forming around their star.