Brightest supernova ever would banish the night for weeks
Friday, January 15, 2016, 1:29 PM - A mysterious object is powering a supernova so bright, it would banish our nights for weeks. Pluto's atmosphere shines in latest imagery. NASA gives us their latest and best views of dwarf planet Ceres. It's Science Pics of the Week!
Mystery of the Brightest Supernova Ever
Imagine an explosion going off in our night sky that instantly banished the darkness, and shone like a second Sun in the sky for weeks.
If a supernova that occurred in a distant galaxy, roughly 3.8 billion years ago had actually happened much more recently and in our own Milky Way galaxy instead, that's exactly what we'd be seeing right now.
According to astronomers working with the All Sky Automated Survey for Supernovae (ASAS-SN) collaboration, supernova ASASSN-15lh was first detected here on Earth in June 2015, and it has proved to be the brightest supernova ever seen - more than twice as bright as the previous brightest, some 570 billion times brighter than our Sun, and around 20 times brighter than everything in the Milky Way galaxy combined.
ASASSN-15lh's host galaxy before the explosion, taken by the Dark Energy Camera (DECam) on the left, and the supernova by the Las Cumbres Observatory Global Telescope Network (LCOGT) 1-meter telescope network on the right. Credit: The Dark Energy Survey, B. Shappee and the ASAS-SN team
What could be powering an explosion this bright? The supernova is so bright that the astronomers can't actually see the source, so they don't know for sure.
They have an idea of what it might be though - a rare kind of supernova remnant, just 16 kilometres across, known as a magnetar. A magnetar is a neutron star - the leftover remnant of a massive star that explodes at the end of its lifespan - that generates an exceptionally powerful magnetic field. This powerful magnetic field makes the stellar remnant especially bright in x-rays and gamma rays, and this radiation makes the expanding cloud of gas and dust from the supernova shine brightly as well.
"If it really is a magnetar, it's as if nature took everything we know about magnetars and turned it up to 11," Krzysztof Stanek, co-principal investigator of the project, invoked Spinal Tap in an Ohio State University press release.
Best Look Yet at Pluto's Hazy Atmosphere
One of the latest downloads from NASA's New Horizons spacecraft is shown above - the highest resolution look so far at the blue-hued haze in Pluto's atmosphere.
According to NASA:
Scientists believe the haze is a photochemical smog resulting from the action of sunlight on methane and other molecules in Pluto’s atmosphere, producing a complex mixture of hydrocarbons such as acetylene and ethylene. These hydrocarbons accumulate into small particles, a fraction of a micrometer in size, and scatter sunlight to make the bright blue haze seen in this image.
As they settle down through the atmosphere, the haze particles form numerous intricate, horizontal layers, some extending for hundreds of miles around Pluto. The haze layers extend to altitudes of over 120 miles (200 kilometers).
Adding to the stark beauty of this image are mountains on Pluto’s limb (on the right, near the 4 o’clock position), surface features just within the limb to the right, and crepuscular rays (dark finger-like shadows to the left) extending from Pluto’s topographic features.
As better and better imagery gets downlinked from New Horizons, we are being treated to incredible new views of this fascinating distant world. Stay tuned for more!
Best Views of the Cratered Surface of Ceres
Speaking of "best looks yet from NASA", their Dawn spacecraft has been sending back new images snapped during its Low-Altitude Mapping Orbit (LAMO), and the view is pretty amazing.
Click on the above images to see the full versions.
What about Occator Crater and its mysterious bright spots? We're still waiting for the LAMO view of those!
Watch again: Slug-life on Pluto? Probably not...