Science Pics of the Week: A surprising triple-sunrise planet

The triple-sunrises of super-Jupiter world HD 131399Ab. Credit: ESO/L. Calçada/M. Kornmesser

Friday, July 8, 2016, 4:41 PM - Astronomers discover a planet that they didn't think could exist,  Dawn discovers sunless craters on Ceres, and Super Typhoon Nepartak's mesmerizing crawl across the Pacific. It's Science Pics of the Week!

First-ever triple-sun planet

Move aside, Tatooine. You were remarkable for awhile, with your double sunrises and sunsets, but astronomers just discovered a planet that goes beyond that.

HD 131399Ab - a gas giant roughly four times more massive than Jupiter, located around 320 light years from Earth - is in a wide orbit around a bright blue-white star, taking 550 Earth years to go around once. Remarkably, in a first, this planet and its star are locked in a dance with two other stars, as shown in the video below.

The fact that this planet is able to stay in this orbit, even as the two other stellar companions tug on it as it circles its parent star, is a surprise. While a planet orbiting around three closely-grouped stars would not be particularly unusual, it was thought that the configuration seen with the HD 131399 system would be a highly unstable arrangement, with the planet being flung out of the star system after only a very short time. HD 131399Ab has managed to hang on to its orbit for about 16 million years, though. That's quite young, for a planet, so who knows what may happen as the system ages. For now, though, it stands out among the planetary systems we've found so far.

Even more remarkable, the planet is large enough, and at the moment, far away enough from any of its stellar family members, that it was directly imaged from the ground, using the European Southern Observatory's SPHERE imager on the Very Large Telescope (VLT) in Chile.

The HD 131399 trinary star system, as seen in infrared light by the ESO's Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) imager, with exoplanet HD 131399Ab. Credit: ESO/K. Wagner et al.

According to the astronomers, more observations of the system will be needed to lock down the exact orbits of all the members of this distant star system, but from what they can see based on their current observations, the orbit does appear to be stable.

"It is not clear how this planet ended up on its wide orbit in this extreme system, and we can't say yet what this means for our broader understanding of the types of planetary systems, but it shows that there is more variety out there than many would have deemed possible," concludes Kevin Wagner. "What we do know is that planets in multi-star systems have been studied far less often, but are potentially just as numerous as planets in single-star systems."

There may be ice-filled craters at Ceres' poles

Look up at the face of our cratered Moon, and you will notice that the craters get more and more shadowed the closer to the north and south pole they are. As NASA's Dawn spacecraft has been orbiting Ceres, in the asteroid belt, it has noticed the same thing at this dwarf planet's polar regions.

As the video states, ice may have been accumulating in these dark craters for billions of years.

If this ice can be detected and studied, it may yield up answers to what the early solar system was like, and how the inner solar system evolved over time.

'Perfect' storm Nepartak

Super Typhoon Nepartak cut a swath of destruction through Taiwan on Friday, and will soon make landfall in eastern China. In its early days out at sea, however, the storm displayed a rare magnificence, at least from the safety of space.

Below is a time-lapse animation of visible images taken by Japan's Himawari-8 satellite on July 6, 2016.

The Himawari-8 satellite shows Super Typhoon #Nepartak churning through the Pacific Ocean. https://t.co/IXX2nuFNhM pic.twitter.com/iOBt2wfCNP

— NOAA Satellites (@NOAASatellites) July 6, 2016

Himawari's infrared view of the storm is possibly even better, though, as shown in the false-colour animation below.

#Nepartak's last 30 hours, every 150 seconds #Himawari IR pic.twitter.com/Ds6NsHSNff

— Dan Lindsey (@DanLindsey77) July 6, 2016

Meanwhile, the high-resolution imagery taken by Himawari allows us to gaze straight down the eye of the storm, to see what's going on inside that swirling vortex, and even the structure of the clouds in the eyewall.

Here's the full-day loop showing the cool cloud structures inside #Nepartak's eye - #Himawari 500-m VIS, 2.5-min pic.twitter.com/BtINtcxI1V

— Dan Lindsey (@DanLindsey77) July 7, 2016

Incredible!

While we can't dismiss the impacts of these storms on those in their path, imagery such as this allows atmospheric scientists to observe and study these storms in remarkable detail. This helps to increase our knowledge of how these storms form, move and dissipate, which improves our ability to forecast their formation, track and impact.

Imagery like this will soon be available over the western hemisphere, thanks to NASA and NOAA's GOES-R satellite, which is launching in November 2016.

Sources: ESO | NASA Goddard | Andrew Freedman/Mashable | Dan Lindsey | NASA/NOAA