Light Pillars over Whitefish Bay

What’s happening in the sky? Unusual lights appeared last week to hover above Whitefish Bay on the eastern edge of Lake Superior between the USA and Canada. Unsure of the cause, the Michigan-based astrophotographer switched camera lenses — from fisheye to telephoto — and soon realized he was seeing light pillars: vertical lines of light over a ground source that reflect from falling ice crystals. As the ground temperature was above freezing, the flat crystals likely melted as they approached the ground, creating a lower end to the vertical light pillars. The red ground lights originated from wind turbines on Ile Parisienne, a Canadian Island visible across the bay. [via NASA] https://ift.tt/2PkGsYR
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Hyperion: Largest Known Galaxy Proto Supercluster

How did galaxies form in the early universe? To help find out, astronomers surveyed a patch of dark night sky with the Very Large Telescope array in Chile to find and count galaxies that formed when our universe was very young. Analysis of the distribution of some distant galaxies (redshifts near 2.5) found an enormous conglomeration of galaxies that spanned 300 million light years and contained about 5,000 times the mass of our Milky Way Galaxy. Dubbed Hyperion, it is currently the largest and most massive proto-supercluster yet discovered in the early universe. A proto-supercluster is a group of young galaxies that is gravitationally collapsing to create a supercluster, which itself a group of several galaxy clusters, which itself is a group of hundreds of galaxies, which itself is a group of billions of stars. In the featured visualization, massive galaxies are depicted in white, while regions containing a large amount of smaller galaxies are shaded blue. Identifying and understanding such large groups of early galaxies contributes to humanity’s understanding of the composition and evolution of the universe as a whole. [via NASA] https://ift.tt/2O1dngi

Halo of the Cat s Eye

Not a Falcon 9 rocket launch after sunset, the Cat’s Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this composited picture, processed to reveal an enormous but extremely faint halo of gaseous material, over three light-years across. Made with data from ground- and space-based telescopes it shows the extended emission which surrounds the brighter, familiar planetary nebula. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. But only more recently have some planetaries been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star’s evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the outer filamentary portions of this halo to be 50,000 to 90,000 years old. [via NASA] https://ift.tt/2J867hR

Summer to Winter Milky Way

Taken near local midnight, this autumn night’s panorama follows the arch of the Milky Way across the northern horizon from the High Fens, Eifel Nature Park at the border of Belgium and Germany. Shift your gaze across the wetlands from west to east (left to right) and you can watch stars once more prominent in northern summer give way to those that will soon dominate northern winter nights. Setting, wanderer Mars is brightest at the far left, still shinning against almost overwhelming city lights along the southwestern horizon. Bright stars Altair, Deneb, and Vega form the northern sky’s summer triangle, straddling the Milky Way left of center. Part of the winter hexagon Capella and Aldebaran, along with the beautiful Pleiades star cluster shine across the northeastern sky. The line-of-sight along the hikers boardwalk leads almost directly toward the Big Dipper, an all season asterism from these northern latitudes. Follow the Big Dipper’s pointer stars to Polaris and the north celestial pole nearly centered above it. Andromeda, the other large galaxy in the skyscape, is near the top of the frame. [via NASA] https://ift.tt/2NP5Ml4

Cherenkov Telescope at Sunset

On October 10, a new telescope reflected the light of the setting Sun. With dark horizon above and sunset colors below, its segmented mirror inverts an image of the beautiful evening sky in this snapshot from the Roque del Los Muchachos Observatory on the Canary Island of La Palma. The mirror segments cover a 23 meter diameter and are mounted in the open structure of the Large Scale Telescope 1, inaugurated as the first component of the Cherenkov Telescope Array (CTA). Most ground-based telescopes are hindered by the atmosphere that blurs, scatters, and absorbs light. But cherenkov telescopes are designed to detect very high energy gamma rays and actually require the atmosphere to operate. As the gamma rays impact the upper atmosphere they produce air showers of high-energy particles. A large, fast camera at the common focus images the brief flashes of optical light, called Cherenkov light, created by the air shower particles. The flashes reveal the incoming gamma ray timing, direction, and energy. Ultimately more than 100 Cherenkov telescopes are planned for the CTA at locations in both northern and southern hemispheres on planet Earth. [via NASA] https://ift.tt/2AggvBy

Jupiter in Ultraviolet from Hubble

Jupiter looks a bit different in ultraviolet light. To better interpret Jupiter’s cloud motions and to help NASA’s robotic Juno spacecraft understand the planetary context of the small fields that it sees, the Hubble Space Telescope is being directed to regularly image the entire Jovian giant. The colors of Jupiter being monitored go beyond the normal human visual range to include both ultraviolet and infrared light. Featured from 2017, Jupiter appears different in near ultraviolet light, partly because the amount of sunlight reflected back is distinct, giving differing cloud heights and latitudes discrepant brightnesses. In the near UV, Jupiter’s poles appear relatively dark, as does its Great Red Spot and a smaller (optically) white oval to the right. The String of Pearl storms farther to the right, however, are brightest in near ultraviolet, and so here appear (false-color) pink. Jupiter’s largest moon Ganymede appears on the upper left. Juno continues on its looping 53-day orbits around Jupiter, while Earth-orbiting Hubble is now recovering from the loss of a stabilizing gyroscope. [via NASA] https://ift.tt/2OpUXec

Orion in Red and Blue

When did Orion become so flashy? This colorful rendition of part of the constellation of Orion comes from red light emitted by hydrogen and sulfur (SII), and blue-green light emitted by oxygen (OIII). Hues on the featured image were then digitally reassigned to be indicative of their elemental origins — but also striking to the human eye. The breathtaking composite was painstakingly composed from hundreds of images which took nearly 200 hours to collect. Pictured, Barnard’s Loop, across the image bottom, appears to cradle interstellar constructs including the intricate Orion Nebula seen just right of center. The Flame Nebula can also be quickly located, but it takes a careful eye to identify the slight indentation of the dark Horsehead Nebula. As to Orion’s flashiness — a leading explanation for the origin of Barnard’s Loop is a supernova blast that occurred about two million years ago. [via NASA] https://ift.tt/2OpgeF4