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14/12/2019

Sience & Technology - Astronomy picture of the day : Interstellar Comet 2I/Borisov

2019 December 14
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Interstellar Comet 2I/Borisov 
Image Credit: NASAESA, and D. Jewitt (UCLA) et al.
Explanation: From somewhere else in the Milky Way galaxy, Comet 2I/Borisov is just visiting the Solar System. Discovered by Crimean amateur astronomer Gennady Borisov on August 30, 2019, the first known interstellar comet is captured in these two recent Hubble Space Telescope images. On the left, a distant background galaxy near the line-of-sight to Borisov is blurred as Hubble tracked the speeding comet and dust tail about 327 million kilometers from Earth. At right, 2I/Borisov appears shortly after perihelion, its closest approach to Sun. Borisov's closest approach to our fair planet, a distance of about 290 million kilometers, will come on December 28. Even though Hubble's sharp images don't resolve the comet's nucleus, they do lead to estimates of less than 1 kilometer for its diameter.

12/12/2019

Science & Technology - Astronomy picture of the day : Lines of Time

2019 December 12
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Lines of Time 
Image Credit & CopyrightAnton Komlev
Explanation: In time stars trace lines through the night sky on a rotating planet. Taken over two hours or more, these digitally added consecutive exposures were made with a camera and wide angle lens fixed to a tripod near Orel farm, Primorsky Krai, Russia, planet Earth. The stars trail in concentric arcs around the planet's south celestial pole below the scene's horizon, and north celestial pole off the frame at the upper right. Combined, the many short exposures also bring out the pretty star colours. Bluish trails are from stars hotter than Earth's Sun, while yellowish trails are from cooler stars. A long time ago this tree blossomed, but now reveals the passage of time in the wrinkled and weathered lines of its remains.

05/12/2019

Science & Technology - Astronomy picture of the day : Spiral Galaxy NGC 6744

2019 December 5
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Spiral Galaxy NGC 6744 
Image Credit & CopyrightZhuokai Liu, Jiang Yuhang
Explanation: Beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo and appears as only a faint, extended object in small telescopes. We see the disk of the nearby island universe tilted towards our line of sight in this remarkably detailed galaxy portrait, a telescopic view that spans an area about the angular size of a full moon. In it, the giant galaxy's elongated yellowish core is dominated by the light from old, cool stars. Beyond the core, grand spiral arms are filled with young blue star clusters and speckled with pinkish star forming regions. An extended arm sweeps past a smaller satellite galaxy (NGC 6744A) at the lower right. NGC 6744's galactic companion is reminiscent of the Milky Way's satellite galaxy the Large Magellanic Cloud.

04/12/2019

Science & Technology - Astronomy picture of the day : Electric Night

2019 December 4
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Electric Night 
Image Credit & Copyright: Ivan Pedretti
Explanation: It may appear, at first, like the Galaxy is producing the lightning, but really it's the Earth. The featured nighttime landscape was taken from a southern tip of the Italian Island of Sardinia in early June. The foreground rocks and shrubs are near the famous Capo Spartivento Lighthouse, and the camera is pointed south toward Algeria in Africa. In the distance, across the Mediterranean Sea, a thunderstorm is threatening, with several electric lightning strokes caught together during this 25-second wide-angle exposure. Much farther in the distance, strewn about the sky, are hundreds of stars in the neighborhood of our Sun in the Milky Way Galaxy. Furthest away, and slanting down from the upper left, are billions of stars that together compose the central band of our Milky Way.

30/11/2019

Science & Technology - Astronomy picture of the day : A Cold River to Orion

2018 November 30
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A Cold River to Orion 
Image Credit & CopyrightJuris Sennikovs
Explanation: Ice is forming on the river Lielupe as it flows through the landscape in this winter's night scene. Even in motion the frigid water still reflects a starry sky, though. The well planned, Orion-centered panorama looks toward the south, taken in three exposures from a bridge near the village of Stalgene, Latvia, planet Earth. Drifting pancakes of ice leave streaks in the long exposures, while familiar stars of Orion and the northern winter night appear above and below the horizon. Village lights along the horizon include skyward beams from the local community church. This image was a first place winner in the 2018 StarSpace astrophotography competition.

25/11/2019

Science & Technology - Astronomy picture of the day : NGC 6995: The Bat Nebula

2019 November 25
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NGC 6995: The Bat Nebula 
Image Credit & Copyright: Josep Drudis
Explanation: Do you see the bat? It haunts this cosmic close-up of the eastern Veil NebulaThe Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape and covers nearly 3 degrees on the sky toward the constellation of the Swan (Cygnus), the Bat Nebula, NGC 6995, spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's estimated distance, a reassuring 1,400 light-years from planet Earth. In the composite of image data recorded through broad and narrow band filters, emission from hydrogen atoms in the remnant is shown in red with strong emission from oxygen and nitrogen atoms shown in hues of blue. Of course, in the western part of the Veil lies another seasonal apparition: the Witch's Broom Nebula.

22/11/2019

Science & Technology - Astronomy picture of the day : Orion Rising

2019 November 22
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Orion Rising 
Image Credit & Copyright: Vitalij Kopa
Explanation: Looking toward the east in the early hours of a September morning this single exposure made with tripod and camera captured a simple visual experience. Rising above the tree-lined slope are familiar stars in planet Earth's northern night and the constellation Orion the Hunter. Brighter stars marking the celestial Hunter's shoulder (Betelgeuse), foot (Rigel), belt, and sword are clearly reflected in the calm waters from northern Latvia's Vitrupe river. Of course, winter is coming to planet Earth's northern hemisphere. By then Orion and this beautiful starry vista will be seen rising in early evening skies.

20/11/2019

Ciência & Tecnologia - Saude/Medecina : Fornos de microondas, perigo ?

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Science & Technology - Astronomy picture of the day : Arp 273: Battling Galaxies from Hubble

2019 November 20
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Arp 273: Battling Galaxies from Hubble 
Image Credit: NASAESAHubbleProcessing & Copyright: Rudy Pohl
Explanation: What's happening to these spiral galaxies? Although details remain uncertain, there sure seems to be a titanic battle going on. The upper galaxy is labelled UGC 1810 by itself, but together with its collisional partners is known as Arp 273. The overall shape of the UGC 1810 -- in particular its blue outer ring -- is likely a result of wild and violent gravitational interactions. The blue color of the outer ring at the top is caused by massive stars that are blue hot and have formed only in the past few million years. The inner part of the upper galaxy -- itself an older spiral galaxy -- appears redder and threaded with cool filamentary dust. A few bright stars appear well in the foreground, unrelated to colliding galaxies, while several far-distant galaxies are visible in the background. Arp 273 lies about 300 million light years away toward the constellation of Andromeda. Quite likely, UGC 1810 will devour its galactic sidekicks over the next billion years and settle into a classic spiral form.

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