Science & Technology - Astronomy picture of the day - 2019 January 13 : "Tycho's Supernova Remnant in X-ray"

"Tycho's Supernova Remnant in X-ray"  

Image Credit: NASA / CXC / F.J. Lu (Chinese Academy of Sciences) et al.

Explanation: What star created this huge puffball? What's pictured is the hot expanding nebula of Tycho's supernova remnant, the result of a stellar explosion first recorded over 400 years ago by the famous astronomer Tycho Brahe. The featured image is a composite of three X-ray colors taken by the orbiting Chandra X-ray Observatory. The expanding gas cloud is extremely hot, while slightly different expansion speeds have given the cloud a puffy appearance. Although the star that created SN 1572, is likely completely gone, a star dubbed Tycho G, too dim to be discerned here, is thought to be a companion. Finding progenitor remnants of Tycho's supernova is particularly important because the supernova is of Type Ia, an important rung in the distance ladder that calibrates the scale of the visible universe. The peak brightness of Type Ia supernovas is thought to be well understood, making them quite valuable in exploring the relationship between faintness and farness in the distant universe.

Science & Technology - Astronomy picture of the day, 2019 January 12 - Milky Way Falls

Milky Way Falls 

Image Credit & Copyright: Yuri Beletsky (Carnegie Las Campanas Observatory, TWAN)

Explanation: It can be the driest place on planet Earth, but water still flows in Chile's Atacama desert, high in the mountains. After discovering this small creek with running water, the photographer returned to the site to watch the Milky Way rise in the dark southern skies, calculating the moment when Milky Way and precious flowing water would meet. In the panoramic night skyscape, stars and nebulae immersed in the glow along the Milky Way itself also shared that moment with the Milky Way's satellite galaxies the Large and Small Magellanic clouds above the horizon at the right. Bright star Beta Centauri is poised at the very top of the waterfall. Above it lies the dark expanse of theCoalsack nebula and the stars of the Southern Cross.

Music live - Video - Ennio Morricone - Katica Illényi & Győr Philharmonic Orchestra : "Once Upon a Time in the West"

"Once Upon a Time in the West"

Science - Astronomy picture of the day - 2019 January 11 : Partial Eclipse over Beijing

Partial Eclipse over Beijing 
Image Credit & Copyright: Li Zhaoqi

Explanation: On January 6 the New Moon rose in silhouette with the Sun seen from northeastern Asia. Near maximum, the dramatic partial solar eclipse is captured in this telephoto view through hazy skies. In the foreground, the hill top Wanchun pavilion overlooking central Beijing's popular Forbidden City hosts eclipse-watching early morning risers. This was the first of five, three solar and two lunar, eclipses for 2019. Next up is a total lunar eclipse during this month's Full Perigee Moon. At night on January 21, that celestial shadow play will be visible from the hemisphere of planet Earth that includes the Americas, Europe, and western Africa.

Science & Technologie - Astronomy picture of the day - 2019 January 10 - Vela Supernova Remnant Mosaic

Vela Supernova Remnant Mosaic  
Image Credit & Copyright: Robert Gendler, Roberto Colombari, Digitized Sky Survey (POSS II)

Explanation: The plane of our Milky Way Galaxy runs through this complex and beautiful skyscape. Seen toward colorful stars near the northwestern edge of the constellation Vela (the Sails), the 16 degree wide, 200 frame mosaic is centered on the glowing filaments of the Vela Supernova Remnant, the expanding debris cloud from the death explosion of a massive star. Light from the supernova explosion that created the Vela remnant reached Earth about 11,000 years ago. In addition to the shocked filaments of glowing gas, the cosmic catastrophe also left behind an incredibly dense, rotating stellar core, the Vela Pulsar. Some 800 light-years distant, the Vela remnant is likely embedded in a larger and older supernova remnant, the Gum Nebula. Objects identified in this broad mosaic include emission and reflection nebulae, star clusters, and the remarkable Pencil Nebula.

Science & Technologie - Boeing dévoile un concept d’ailes d'avion ultra fines

Boeing et la Nasa développent depuis dix ans des ailes d’avions ultra-minces à l’aérodynamique particulièrement soignée. 

Décidément, Boeing sait faire preuve d’inventivité quand il s’agit de donner des ailes à ses nouveaux appareils. Après avoir créé des ailes repliables pour son 777X, afin qu’il puisse mieux se faufiler dans les aéroports, il dévoile un concept d’avion à ailes ultra-fines, les ""Transonic Truss-Braced Wings" (TTBW).

Ces ailes ultra-minces de 52 mètres de long (elles aussi pliables) sont soutenues par des mâts. Elles sont destinées à des avions pouvant voler en vol subsonique, jusqu’à Mach 0,8 (980 km/h). Ce design permet d’optimiser l’aérodynamique et de réduire le son émis par l’appareil.

Usine Nouvelle

Science - Astronomy picture of the day - 2019 January 9 - Quadrantids

"Quadrantids"  
Image Credit & Copyright: Daniel López (El Cielo de Canarias)

Explanation: Named for a forgotten constellation, the Quadrantid Meteor Shower is an annual event for planet Earth's northern hemisphere skygazers It usually peaks briefly in the cold, early morning hours of January 4. The shower'sradiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That position is situated near the boundaries of the modern constellations Hercules, Bootes, and Draco. About 30 Quadrantid meteors can be counted in this skyscape composed of digital frames recorded in dark and moonless skies between 2:30am and local dawn. The shower's radiant is rising just to the right of the Canary Island of Tenerife's Teide volcano, and just below the familiar stars of the Big Dipper on the northern sky. A likely source of the dust stream that produces Quadrantid meteors was identified in 2003 as an asteroid. Look carefully and you can also spot a small, telltale greenish coma above the volcanic peak and near the top of the frame. That's the 2018 Christmas visitor to planet Earth's skies, Comet Wirtanen.

Astronomie - Le ciel du 9 janvier 2019

Bienvenue, voici votre carte réglée pour votre lieu d'observation.

Repérez facilement les principales étoiles et planètes, et observez que tout le ciel semble tourner autour de l' étoile polaire ! Ainsi, les astres se lèvent et se couchent, et l'aspect du ciel change au long de la nuit...

Utilisation dehors : imprimez cette carte et placez-la au dessus de votre tête, le repère "Horizon NORD" vers le nord. Comparez au ciel observé !

Pourquoi le ciel change-t-il en permanence ? A cause des mouvements de la Terre: comme la Terre tourne sur elle-même, nous voyons défiler le ciel comme si nous étions sur un manège : tout le ciel paraît tourner au fil des heures, autour d'un point voisin de l'étoile polaire (au centre de la carte). Ceci provoque les "levers" et "couchers" des astres. De plus, la course de la Terre autour du Soleil nous fait découvrir une portion de ciel différente selon la période de l'année.à cause des mouvements des astres eux-mêmes:le Soleil, la Lune, les planètes, ont un mouvement perceptible au fil des jours (ou des semaines) par rapport au fond des étoiles. A l'inverse, les étoiles à l'extérieur de notre système solaire sont tellement lointaines qu'elles paraissent fixes au cours d'une vie humaine.

Stelvision

Astronomy picture of the day - 2019 January 8 - HESS Telescopes Explore the High-Energy Sky

HESS Telescopes Explore the High-Energy Sky  
Video Credit & Copyright: Vikas Chander, H.E.S.S. Collaboration; Music: Emotive Piano by Immersive Music

Explanation: They may look like modern mechanical dinosaurs but they are enormous swiveling eyes that watch the sky. The High Energy Stereoscopic System (H.E.S.S.) Observatory is composed of four 12-meter reflecting-mirror telescopes surrounding a larger telescope housing a 28-meter mirror. They are designed to detect strange flickers of blue light -- Cherenkov radiation --emitted when charged particles move slightly faster than the speed of light in air. This light is emitted when a gamma ray from a distant source strikes a molecule in Earth's atmosphere and starts a charged-particle shower. H.E.S.S. is sensitive to some of the highest energy photons (TeV) crossing the universe. Operating since 2003 in Namibia, H.E.S.S. has searched for dark matter and has discovered over 50 sources emitting high energy radiation including supernova remnants and the centers of galaxies that contain supermassive black holes. Pictured last September, H.E.S.S. telescopes swivel and stare in time-lapse sequences shot in front of our Milky Way Galaxy and the Magellanic Clouds -- as the occasional Earth-orbiting satellite zips by.

Music live - Video - Mozart - Aksel Rykkvin (13 years) : "Laudate Dominum"

"Laudate Dominum"