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14/05/2021
I-PHONE ASTUCES - Recharger l'iPhone 2 fois plus vite
ASTRONOMY - M104: The Sombrero Galaxy
Image Credit & Copyright: Bray Falls
Explanation: A gorgeous spiral galaxy, M104 is famous for its nearly edge-on profile featuring a broad ring of obscuring dust lanes. Seen in silhouette against an extensive central bulge of stars, the swath of cosmic dust lends a broad brimmed hat-like appearance to the galaxy suggesting a more popular moniker, the Sombrero Galaxy. This sharp optical view of the well-known galaxy made from ground-based image data was processed to preserve details often lost in overwhelming glare of M104's bright central bulge. Also known as NGC 4594, the Sombrero galaxy can be seen across the spectrum, and is host to a central supermassive black hole. About 50,000 light-years across and 28 million light-years away, M104 is one of the largest galaxies at the southern edge of the Virgo Galaxy Cluster. Still the colorful spiky foreground stars in this field of view lie well within our own Milky Way galaxy.
PRATIQUE/POURQUOI - Pourquoi l'oignon nous fait-il pleurer ?
13/05/2021
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ASTRONOMY - The Comet, the Whale, and the Hockey Stick
2021 May 13
Image Credit & Copyright: Grand Mesa Observatory, Terry Hancock / Tom Masterson
Explanation: Closest to the Sun on March 1, and closest to planet Earth on April 23, this Comet ATLAS (C/2020 R4) shows a faint greenish coma and short tail in this pretty, telescopic field of view. Captured at its position on May 5, the comet was within the boundaries of northern constellation Canes Venatici (the Hunting Dogs), and near the line-of-sight to intriguing background galaxies popularly known as the Whale and the Hockey Stick. Cetacean in appearance but Milky Way sized, NGC 4631 is a spiral galaxy seen edge-on at the top right, some 25 million light-years away. NGC 4656/7 sports the bent-stick shape of interacting galaxies below and left of NGC 4631. In fact, the distortions and mingling trails of gas detected at other wavelengths suggest the cosmic Whale and Hockey Stick have had close encounters with each other in their distant past. Outbound and only about 7 light-minutes from Earth this Comet ATLAS should revisit the inner solar system in just under 1,000 years.
12/05/2021
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ASTRONOMY - A Meteor and the Gegenschein
2021 May 12
Image Credit: J.C. Casado, StarryEarth, EELabs, TWAN
Explanation: Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles. These dust particles are millimeter sized splinters from asteroids and orbit in the ecliptic plane of the planets. Pictured here from last March is one of the more spectacular pictures of the gegenschein yet taken. The deep exposure of an extremely dark sky over Teide Observatory in Spain's Canary Islands shows the gegenschein as part of extended zodiacal light. Notable background objects include a bright meteor (on the left), the Big Dipper (top right), and Polaris (far right). The meteor nearly points toward Mount Teide, Spain's highest mountain, while the Pyramid solar laboratory is visible on the right. During the day, a phenomenon like the gegenschein called the glory can be seen in reflecting air or clouds opposite the Sun from an airplane.
11/05/2021
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ASTRONOMY - Lightning and Orion Beyond Uluru
2021 May 11
Image Credit & Copyright: Park Liu
Explanation: What's happening behind Uluru? A United Nations World Heritage Site, Uluru is an extraordinary 350-meter high mountain in central Australia that rises sharply from nearly flat surroundings. Composed of sandstone, Uluru has slowly formed over the past 300 million years as softer rock eroded away. In the background of the featured image taken in mid-May, a raging thunderstorm is visible. Far behind both Uluru and the thunderstorm is a star-filled sky highlighted by the constellation of Orion. The Uluru region has been a home to humans for over 22,000 years. Local indigenous people have long noted that when the stars that compose the modern constellation of Orion first appear in the night sky, a hot season involving lightning storms will soon be arriving.
10/05/2021
ASTRONOMY - Star Clusters M35 and NGC 2158
2021 May 10
Image Credit & Copyright: CFHT, Coelum, MegaCam, J.-C. Cuillandre (CFHT) & G. A. Anselmi (Coelum)
Explanation: Clusters of stars can be near or far, young or old, diffuse or compact. The featured image shows two quite contrasting open star clusters in the same field. M35, on the lower left, is relatively nearby at 2800 light years distant, relatively young at 150 million years old, and relatively diffuse, with about 2500 stars spread out over a volume 30 light years across. Bright blue stars frequently distinguish younger open clusters like M35. Contrastingly, NGC 2158, on the upper right, is four times more distant than M35, over 10 times older, and much more compact. NGC 2158's bright blue stars have self-destructed, leaving cluster light to be dominated by older and yellower stars. In general, open star clusters are found in the plane of our Milky Way Galaxy, and contain anywhere from 100 to 10,000 stars -- all of which formed at nearly the same time. Both open clusters M35 and NGC 2158 can be found together with a small telescope toward the constellation of the Twins (Gemini).
BIOMES - La Corse
La Corse, au cœur de l’environnement méditerranéen FuturaSciences
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2021 May 11 Lightning and Orion Beyond Uluru Image Credit & Copyright: Park Liu Explanation: What's happening behind Uluru? A Un...
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Extraordinary Solar Halos Image Credit & Copyright : Magnus Edback Explanation: Welcome to the December Solstice, the first...