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Astronomers have found the first Jupiter-like exoplanet with no clouds or haze. It’s an ideal object for further study with the James Webb Space Telescope.


Can you picture Jupiter without any observable clouds or haze? It isn’t easy since Jupiter’s latitudinal cloud bands and its Great Red Spot are iconic visual features in our Solar System. Those features are caused by upswelling and descending gas, mostly ammonia. After Saturn’s rings, Jupiter’s cloud forms are probably the most recognizable feature in the Solar System.

Now astronomers with the Center for Astrophysics | Harvard & Smithsonian (CfA) have found a planet similar in mass to Jupiter, but with a cloud-free atmosphere.

Axions may be produced thermally inside the cores of neutron stars (NSs), escape the stars due to their feeble interactions with matter, and subsequently convert into x rays in the magnetic fields surrounding the stars. We show that a recently discovered excess of hard x-ray emission in the 2—8 keV energy range from the nearby magnificent seven isolated NSs could be explained by this emission mechanism. These NSs are unique in that they had previously been expected to only produce observable flux in the UV and soft x-ray bands from thermal surface emission at temperatures $\ensuremath{\sim}100\text{ }\text{ }\mathrm{eV}$. No conventional astrophysical explanation of the magnificent seven hard x-ray excess exists at present.

No one has yet managed to travel through time – at least to our knowledge – but the question of whether or not such a feat would be theoretically possible continues to fascinate scientists.

As movies such as The Terminator, Donnie Darko, Back to the Future and many others show, moving around in time creates a lot of problems for the fundamental rules of the Universe: if you go back in time and stop your parents from meeting, for instance, how can you possibly exist in order to go back in time in the first place?

It’s a monumental head-scratcher known as the ‘grandfather paradox’, but in September last year a physics student Germain Tobar, from the University of Queensland in Australia, said he has worked out how to “square the numbers” to make time travel viable without the paradoxes.

Spiral galaxies are one of the most commonly known types of galaxy. Most people think of them as large round disks, and know that our Milky Way is counted among their number. What most people don’t realize is that many spiral galaxies have a type of warping effect that, when you look at them edge on, can make it seem like they are forming a wave. Now scientists, led by Xinlun Chen at the University of Virginia, have studied millions of stars in the Milky Way and begun to develop a picture of a “wave” passing through our own galaxy.

Since humans are not currently able to view the Milky Way in an edge-on orientation, they must resort to more brute force methods to develop models about the what, if any, wave our galaxy has. Luckily, scientists now have the tools to do so, in the form of the Sloan Digital Sky Survey and ESA’s Gaia satellite.

The method the team used was to try to identify and track the motions of as many stars as possible. To do this, they used the Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, which is part of the SDSS. This preliminary data allowed them to look at both the chemical compositions as well as the motions of hundreds of thousands of stars. While this motion data was helpful in starting to form the picture of the Milky Way’s wave, it was not sufficient to complete it.