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08/07/2019

Science & Technology - Astronomy picture of the day : The Galactic Center in Radio from MeerKAT

2019 July 8
See Explanation.
Moving the cursor over the image will bring up an annotated version.
Clicking on the image will bring up the highest resolution version
available.
The Galactic Center in Radio from MeerKAT 
Image Credit: MeerKATSARAO
Explanation: What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio, the galactic center can be imaged and shows itself to be quite an interesting and active place. The featured picture shows the inaugural image of the MeerKAT array of 64 radio dishes just completed in South Africa. Spanning four times the angular size of the Moon (2 degrees), the image is impressively vast, deep, and detailed. Many known sources are shown in clear detail, including many with a prefix of Sgr, since the Galactic Center is in the direction of the constellation Sagittarius. In our Galaxy's Center lies Sgr A, found here just to the right of the image center, which houses the Milky Way's central supermassive black hole. Other sources in the image are not as well understood, including the Arc, just to the left of Sgr A, and numerous filamentary threads. Goals for MeerKAT include searching for radio emission from neutral hydrogen emitted in a much younger universe and brief but distant radio flashes.

Music - Live - Video - Verdi / Angela Gheorghiu (Soprano) and Roberto Alagna : La Traviata - Brindisi,

"La Traviata - Brindisi" 


During the Prom at the Palace event held to celebrate the Queen's Golden Jubilee, 2002.

07/07/2019

Science & Technology - Astronomy picture of the day : Crescent Saturn

2019 July 7
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Crescent Saturn 
Image Credit: NASAESASSICassini Imaging Team
Explanation: Saturn never shows a crescent phase -- from Earth. But when viewed from beyond, the majestic giant planet can show an unfamiliar diminutive sliver. This image of crescent Saturn in natural color was taken by the robotic Cassini spacecraft in 2007. The featured image captures Saturn's majestic rings from the side of the ring plane opposite the Sun -- the unilluminated side -- another vista not visible from Earth. Pictured are many of Saturn's photogenic wonders, including the subtle colors of cloud bands, the complex shadows of the rings on the planet, and the shadow of the planet on the rings. A careful eye will find the moons Mimas (2 o'clock) and Janus (4 o'clock), but the real challenge is to find Pandora (8 o'clock). Saturn is now nearly opposite from the Sun in the Earth's sky and so can be seen in the evening starting just after sunset for the rest of the night.

05/07/2019

Science & Technology - Astronomy picture of the day : La Silla Eclipse Sequence

2019 July 5
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La Silla Eclipse Sequence 
Image Credit & CopyrightPetr Horálek
Explanation: The road to the high mountaintop La Silla Observatory in the Chilean Atacama Desert also led in to the path of July 2nd's total solar eclipse. Recorded at regular intervals before and after the total eclipse phase, the frames in this composite sequence include the moment the Moon's dark shadow fell across some of planet Earth's advanced large telescopes. The dreamlike view looks west toward the setting Sun and the approaching Moon shadow. In fact La Silla was a little north of the shadow track's center line, so the region's stunning, clear skies are slightly brighter to the north (right) in the scene.

02/07/2019

Science & Technologie - Avions du futur : L'avion supersonique silencieux de Lockheed Martin

L'avion supersonique silencieux de Lockheed Martin
Sur ce supersonique imaginé par Lockheed Martin, les ailes forment un V assez prononcé et les moteurs sont installés au-dessus. Cette disposition devrait empêcher, ou réduire fortement, le « bang », cet énorme bruit qui suit un avion se déplaçant plus vite que les ondes sonores, franchissant ainsi le mur du son. Un tel avion pourrait donc voler en supersonique au-dessus des continents. 
© Lockheed Martin

Science & Technologie - Santé/Médecine : Pourquoi notre corps souffre pendant la canicule

Jolie femme en maillot de bain noir sur Maldives photo libre de droitsElle fait suer et alourdit nos jambes. Elle nous prive d'appétit, elle nous fatigue et parfois elle tue... Pourquoi la chaleur est-elle aussi méchante ? Les explications.
Tanguy de l'Espinay

Science & Technology - Astronomy picture of the day : NGC 1566: The Spanish Dancer Spiral Galaxy

2019 July 2
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NGC 1566: The Spanish Dancer Spiral Galaxy 
Image Credit: NASAESAHubbleProcessing & Copyright: Leo Shatz
Explanation: If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe containing billions of stars and situated about 40 million light-years away toward the constellation of the Dolphinfish (Dorado),NGC 1566 presents a gorgeous face-on view. Classified as a grand design spiral, NGC 1566's shows two prominent and graceful spiral arms that are traced by bright blue star clusters and dark cosmic dust lanes. Numerous Hubble Space Telescope images of NGC 1566 have been taken to study star formationsupernovas, and the spiral's unusually active center. Some of these images, stored online in the Hubble Legacy Archive, were freely downloaded, combined, and digitally processed by an industrious amateur to create the featured image. NGC 1566's flaring center makes the spiral one of the closest and brightest Seyfert galaxies, likely housing a central supermassive black holewreaking havoc on surrounding stars and gas.

01/07/2019

Science & Technology - Astronomy picture of the day : The Big Corona

2019 July 1
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The Big Corona 
Image Credit & Copyright: P. Horálek, Z. Hoder, M. Druckmüller, P. Aniol, S. Habbal / Solar Wind Sherpas
Explanation: Most photographs don't adequately portray the magnificence of the Sun's corona. Seeing the corona first-hand during a total solar eclipse is unparalleled. The human eye can adapt to see coronal features and extent that average cameras usually cannot. Welcome, however, to the digital age. The featured central image digitally combined short and long exposures that were processed to highlight faint and extended features in the corona of the total solar eclipse that occurred in August of 2017. Clearly visible are intricate layers and glowing caustics of an ever changing mixture of hot gas and magnetic fields in the Sun's corona. Looping prominences appear bright pink just past the Sun'slimb. Faint details on the night side of the New Moon can even be made out, illuminated by sunlight reflected from the dayside of the Full Earth. Images taken seconds before and after the total eclipse show glimpses of the background Sun known as Baily's Beads and Diamond Ring. Tomorrow, a new total solar eclipse will be visible from parts of South America.

Science & Technologie - Santé/Médecine - Video : Les chiffres de notre corps

Les chiffres de notre corps

ASTRONOMIE - LES PLUS BEAUX ASTRES DE LA VOIE LACTéE - Antiope : l’astéroïde double

Découvert en 1866, (90) Antiope est un astéroïde qui possède la caractéristique d'être binaire . Cela signifie qu'il est constitué ...