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Good Friday – Crucifix at the parish- and pilgrimage church Kefermarkt, Upper Austria



This group is popular in the northern spring. Famous as the Leo Triplet, the three magnificent galaxies gather in one field of view. Crowd pleasers when imaged with even modest telescopes, they can be introduced individually as NGC 3628 (left), M66 (bottom right), and M65 (top). All three are large spiral galaxies but they tend to look dissimilar because their galactic disks are tilted at different angles to our line of sight. NGC 3628, also known as the Hamburger Galaxy, is temptingly seen edge-on, with obscuring dust lanes cutting across its puffy galactic plane. The disks of M66 and M65 are both inclined enough to show off their spiral structure. Gravitational interactions between galaxies in the group have left telltale signs, including the tidal tails and warped, inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous view of the region spans almost two degrees (four full moons) on the sky. The field covers about a million light-years at the trio's estimated distance of 30 million light-years. Of course the spiky foreground stars lie within our own Milky Way.


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Theseustempel in the Volksgarten, Vienna, Austria



One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear. The detailed telescopic view reveals M81's bright yellow nucleus, blue spiral arms, pink starforming regions, and sweeping cosmic dust lanes. Some dust lanes actually run through the galactic disk (left of center), contrary to other prominent spiral features though. The errant dust lanes may be the lingering result of a close encounter between M81 and its smaller companion galaxy, M82. Scrutiny of variable stars in M81 has yielded one of the best determined distances for an external galaxy -- 11.8 million light-years.


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Opera Theatre, Yerevan, Armenia. The building, designed by the Armenian architect Alexander Tamanian, was officially opened in 1933 and consists of two concert halls: the Aram Khatchaturian concert hall with 1,400 seats and the Alexander Spendiaryan Opera and Ballet National Theatre with 1,200 seats.



Strange shapes and textures can be found in neighborhood of the Cone Nebula. The unusual shapes originate from fine interstellar dust reacting in complex ways with the energetic light and hot gas being expelled by the young stars. The brightest star on the right of the featured picture is S Mon, while the region just below it has been nicknamed the Fox Fur Nebula for its color and structure. The blue glow directly surrounding S Mon results from reflection, where neighboring dust reflects light from the bright star. The red glow that encompasses the whole region results not only from dust reflection but also emission from hydrogen gas ionized by starlight. S Mon is part of a young open cluster of stars named NGC 2264, located about 2500 light years away toward the constellation of the Unicorn (Monoceros). Even though it points right at S Mon, details of the origin of the mysterious geometric Cone Nebula, visible on the far left, remain a mystery.


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Do you see the dolphin-shaped cloud on Jupiter? The cloud was visible last year during perijove 16, the sixteenth time that NASA's robotic spacecraft Juno passed near Jupiter since it arrived in mid-2016. During each perijove, Juno passes near a slightly different part of Jupiter's cloud tops. The dolphin shape may be surprising but is not scientifically significant -- clouds on Jupiter and Earth are constantly shifting and can temporarily mimic many familiar shapes. The cloud appears in Jupiter's South Temperate Belt (STB), a band of dark and dropping clouds that rings the planet and also contains Oval BA, dubbed Red Spot Jr. The featured image was digitally processed to enhance color and contrast. Juno's next swoop near Jupiter -- perijove 20 -- will occur on late May.


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Groenerei, Bruges, Belgium


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Flemish winged triptych at the Church of the Teutonic Order in Vienna, Austria. Panel paintings and woodcarvings by anonymous masters; polychromy of the woodcarvings by Jan van Wavere, Mechelen, signed 1520. This altarpiece was originally made for St. Mary's Church, Gdańsk, and came to Vienna in 1864.


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The Theatine Church of St. Cajetan (German: Theatinerkirche St. Kajetan) is a Catholic church in Munich. Built from 1663 to 1690, it was founded by Elector Ferdinand Maria and his wife, Henriette Adelaide of Savoy, as a gesture of thanks for the birth of the long-awaited heir to the Bavarian crown, Prince Max Emanuel, in 1662. Now administered by the Dominican Friars, it is also known as the Dominican Priory of St. Cajetan.



The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is the most famous. At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young, O-type stars. Stars in the energetic cluster, cataloged as NGC 2244, are only a few million years young, while the central cavity in the Rosette Nebula, is about 50 light-years in diameter. The nebula can be seen with a small telescope toward the constellation of Monoceros, the Unicorn. This natural appearing telescopic portrait of the Rosette Nebula was made using broadband and narrowband filters, because sometimes roses aren't red.



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Birdhouses on Sidney Spit (part of Gulf Islands National Park Reserve), Sidney Island, British Columbia, Canada.



What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas. The first image was released yesterday and resolved the area around the black hole at the center of galaxy M87 on a scale below that expected for its event horizon. Pictured, the dark central region is not the event horizon, but rather the black hole's shadow -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gas near the event horizon, by strong gravitational lensing deflections, and by the black hole's spin. In resolving this black hole's shadow, the Event Horizon Telescope (ETH) bolstered evidence that Einstein's gravity works even in extreme regions, and gave clear evidence that M87 has a central spinning black hole of about 6 billion solar masses. The EHT is not done -- future observations will be geared toward even higher resolution, better tracking of variability, and exploring the immediate vicinity of the black hole in the center of our Milky Way Galaxy.


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Bottom view of one of the iwans of the Agha Bozorg Mosque, a historical mosque in Kashan, Iran. The mosque, located in the center of the city, was built in the late 18th century by master-mimar Ustad Haj Sa'ban-ali. The mosque has of two large iwans, one in front of the mihrab and the other by the entrance, and a courtyard in the middle.


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Sulfur-salt formation with hot spring at Dallol volcano in the Danakil Depression (Afar Region of Ethiopia).



Sometimes Saturn disappears. It doesn't really go away, though, it just disappears from view when our Moon moves in front. Such a Saturnian eclipse was visible along a small swath of Earth -- from Brazil to Sri Lanka -- near the end of last month. The featured color image is a digital fusion of the clearest images captured by successive videos of the event taken in red, green, and blue, and taken separately for Saturn and the comparative bright Moon. The exposures were taken from South Africa just before occultation -- and also just before sunrise. When Saturn re-appeared on the other side of the Moon almost two hours later, the Sun had risen. This year, eclipses of Saturn by the Moon occur almost monthly, but, unfortunately, are visible only to those with the right location and with clear and dark skies.

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Dome of Salzburg Cathedral, federal state of Salzburg, Austria


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The Falcon 9 rocket on the launch pad of the Vandenberg Air Force Base on January 16, 2016, the day before the launch of the Jason-3 satellite.



If Scorpius looked this good to the unaided eye, humans might remember it better. Scorpius more typically appears as a few bright stars in a well-known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, color filters, and a digital image processor. To bring out detail, the featured image not only involved long duration exposures taken in several colors, but one exposure in a very specific red color emitted by hydrogen. The resulting image shows many breathtaking features. Vertically across the image left is part of the plane of our Milky Way Galaxy. Visible there are vast clouds of bright stars and long filaments of dark dust. Jutting out diagonally from the Milky Way in the image center are dark dust bands known as the Dark River. This river connects to several bright stars on the right that are part of Scorpius' head and claws, and include the bright star Antares. Above and right of Antares is an even brighter planet: Jupiter. Numerous red emission nebulas and blue reflection nebulas are visible throughout the image. Scorpius appears prominently in southern skies after sunset during the middle of the year.


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