Monument Valley
2018-04-11
Fortuitous Flash Candidate for the Farthest Star Yet Seen - Astronomy picture of the day - 2018 April 11
Image Credit: NASA, ESA, & P. Kelly (U. Minnesota) et al.
Explanation: Was this flash the farthest star yet seen? An unexpected flash of light noticed fortuitously on Hubble Space Telescope images may prove to be not only an unusual gravitational lensing event but also an image of a normal star 100 times farther away than any star previously imaged individually. The featured image shows the galaxy cluster on the left complete with many yellowish galaxies, while on the right is an expanded square where a source appeared in 2016 that was not evident in 2011. The spectrum and variability of this source are strangely unlike a supernova, but rather appear more consistent with a normal blue supergiant star magnified by about a factor of 2000 by a confluence of aligned gravitational lenses. Dubbed Icarus, the source is in a galaxy well behind the galaxy cluster and far across the universe -- at redshift 1.5. If the lens interpretation is correct and Icarus is not an exploding star, further observations of it and other similarly magnified stars could give information about the stellar and dark matter content in the galaxy cluster and the universe.
Corriere della Sera - Roma-Barcellona 3-0, l'«impresa impossibile» realizzata ! - Football
Roma ! Non è un miracolo, è di più. I numeri dicono che il Barcellona era imbattuto in Champions (e nella Liga), che aveva la miglior difesa del torneo e che la remuntada la faceva e non la subiva. Batterlo 3-0 sembrava impossibile, ma la sorpresa fa parte del fascino unico del calcio. Quello che era «impossibilissimo» era ridurre Messi e Suarez a due attaccanti di provincia, il primo ammonito per un fallo da terzino su Kolarov e il secondo addirittura per perdita di tempo. Trasformare il Barça in un Crotone, con rispetto parlando per un’altra squadra rossoblù, non era nemmeno nei sogni. E invece è diventato realtà.
Corriere della Sera - Italia
2018-04-10
Dragon Aurora over Norway - Astronomy picture of the day - 2018 April 10
Image Credit & Copyright: Marco Bastoni
Explanation: What's that in the sky? An aurora. A large coronal hole opened last month, a few days before this image was taken, throwing a cloud of fast moving electrons, protons, and ions toward the Earth. Some of this cloud impacted our Earth's magnetosphere and resulted in spectacular auroras being seen at high northern latitudes. Featured here is a particularly photogenic auroral curtain captured above Tromsø Norway. To the astrophotographer, thisshimmering green glow of recombining atmospheric oxygen appeared as a large dragon, but feel free to share what it looks like to you. Although now past Solar Maximum, our Sun continues to show occasional activity creatingimpressive auroras on Earth visible even last week.
2018-04-09
The Sun Unleashed: Monster Filament in Ultraviolet - Astronomy picture of the day - 2018 April 9
Video Credit: NASA GSFC's Scientific Visualization Studio, Solar Dynamics Obs.
Explanation: One of the most spectacular solar sights is an explosive flare. In 2011 June, the Sun unleashed somewhat impressive, medium-sized solar flare as rotation carried active regions of sunpots toward the solar limb. That flare, though, was followed by an astounding gush of magnetized plasma -- a monster filament seen erupting at the Sun's edge in this extreme ultraviolet image from NASA's Solar Dynamics Observatory. Featured here is a time-lapse video of that hours-long event showing darker, cooler plasma raining down across a broad area of the Sun's surface, arcing along otherwise invisible magnetic field lines. An associated coronal mass ejection, a massive cloud of high energy particles, was blasted in the general direction of the Earth,and made a glancing blow to Earth's magnetosphere.
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