Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   This spectacular image shows a range of prominent constellations visible in the night sky over the desert of inner Mongolia, taken in August 2019. The yellowish star in the bottom left side is Arcturus, one of the brightest stars in the night sky, and the brightest in the constellation Boötes. The handle of the Big Dipper points towards this bright star and the Dipper is also visible above Boötes. The Northern Dipper (Bei Dou) is a traditional Chinese constellation. It is considered a chariot in which the Judges for Nobility are sitting. Arcturus is considered a single-star asterism, named the Horn, which forms part of the Chinese super-constellation for the spring, the Azure Dragon of the East. The front of the Northern Dipper points towards the star at the top of the photograph which is now called Polaris, the northern Pole Star. In ancient China, there was no bright star at the pole, so the stars in the nearest vicinity of the pole were considered to belong to the emperor and his family in the constellation the Purple Forbidden Palace. At least as early as mediaeval times, Polaris was considered part of the constellation of the Great Emperor of Heaven. Corona Borealis is also visible in the top right corner of this image, although not in its completeness. It is called the Coiled Thong in China. With its characteristic semi-circular shape, this is one of the smaller constellations of the 88 modern ones, but also can be traced back at least three or four millennia through the Roman “Crown”, the Greek wedding “Wreath”, and the Babylonian “Asterism of Dignity”. The modern name literally means “Northern Crown” in Latin. At the upper-right edge of the image, we find the part of the modern constellation Cassiopeia that is considered the Flying Corridor and an Auxiliary Road in ancient China. The W-shape of Cassiopeia is cut off by the edge of the photograph but the constellations to its south and southeast, Andromeda and Perseus, are clearly recognisable. Prominently we see the Andromeda galaxy, the most distant object that is visible to the unaided eye. It is located at the outermost outliers of the band of the Milky Way, which could explain why it has not been mentioned explicitly in ancient star catalogues, as it was mistakenly thought to be part of the Milky Way. The photograph also shows clearly reddish parts of the Milky Way that don’t appear bright to the naked eye, and also open clusters that are formed from the same molecular cloud, i.e., groups of stars with similar ages. This region is part of many big and small asterisms in traditional Chinese uranology.
Credit: Likai Lin/IAU OAE

Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   As Earth moves around the Sun, the positions of the stars in the night sky appear to change over the course of the year. This is well exemplified in this mosaic, with images taken in all four seasons throughout 2020 in the region of Veneto, Italy, showing the apparent motion of the Ursa Minor and Ursa Major constellations. Ursa Minor, the Little Bear, is a constellation of the northern hemisphere, and it contains the northern celestial pole, in our current epoch marked by a bright star called Polaris or the Pole Star. For centuries Polaris has been used for navigation in the northern hemisphere, as it has been almost at the exact pole position for roughly 200 years. In the Middle Ages and antiquity, there was no pole star; the celestial north pole lay in a dark region and the Greeks considered the “Little She-Bear” as a companion of the “Great She-Bear”, which is more easily recognizable. The brightest stars of these constellations were alternatively also considered as chariots by the Greeks, as written in Aratus’s famous didactic poem from the 3rd century before the common era. The most famous asterism in Ursa Major, composed of seven stars, has different names across the (northern) world. While considered as a chariot by the Greeks, it is “The Northern Dipper” in China, and “The Seven Oxen” for the ancient Romans. It was also the navigational purpose that led to the name The Great She-Bear, Ursa Major; for the Greeks, travelling towards the direction of the horizon above which Ursa Major appears meant moving towards the land of the bears (northern Europe). An animal is clearly recognizable when taking into account all the fainter stars in the vicinity of the seven bright ones. They considered it a female bear because Greek mythology connects this animal with the nymph Callisto, whose story describes the initiation rituals for women. In the top left, we see an image taken on a spring evening, while the image below shows the same portion of the sky on a summer evening. Going counterclockwise, we see the sky during autumn in the bottom right image, while the top right finally shows this portion of the sky in the winter. Note that the relative positions of Ursa Minor and the Big Dipper don’t change, but all stars appear to be moved in a circle around Polaris. This star pointing due north lies at the point where Earth’s rotational axis intersects the celestial sphere. The shift of constellations throughout the year is therefore a globe-clock or a globe-calendar, used by ancient civilizations to measure the year, and to predict the changes of seasons. It helps to establish, for instance, the best time for sowing and sailing as winds change with the seasons.
Credit: Giorgia Hofer/IAU OAE

Caption: 这段延时摄影记录了2020年7月拍摄的三帧画面中标志性的北斗七星的轨迹。影像在意大利的三个地点拍摄：拉瓦雷多三峰（Tre Cime di Lavaredo）奥隆佐迪卡多雷、里特山（Monte Rite）奇比亚纳迪卡多雷，以及拉佐牧场（Casera Razzo）维戈迪卡多雷。这场视觉奥德赛展示了北斗七星的迷人轨迹，并在夜空中绘制出天体画卷。它不仅描绘了这个著名星群的轨迹，还捕捉到2020年7月照亮天空的罕见新智彗星 C/2020 F3 这一非凡的天文事件，为我们的夜空增添了光彩。
Credit: 乔尔贾·霍弗/国际天文学联合会教育办公室 (CC BY 4.0)

Caption: 这段延时摄影捕捉了来自国家天体物理研究所 (INAF) 的 64 米撒丁岛射电望远镜 (SRT) 周围的恒星运动，特别是在天球背景下著名的北斗七星。随着飞机飞过和射电望远镜旋转，著名的北斗七星在天空中下沉，镜头也随之移动。恒星的轨迹与射电望远镜的巨大天线之间的和谐互动，为 2019 年 9 月拍摄的宇宙芭蕾谱写了一曲令人着迷的视觉颂歌。
Credit: Antonio Finazzi/IAU OAE (CC BY 4.0)

Caption: 北斗七星优雅地移动于加利福尼亚州莫诺湖超凡脱俗的凝灰岩层之上。延时摄影捕捉了北斗七星穿过北方地平线直至下合的过程。在莫诺湖的纬度（+38°）上，北斗七星的星星几乎都是环极星，除了阿尔凯德（Alkaid）。北极星位于地平线之上38°的位置，正好在视野的右上角之外。月光将大地笼罩在柔和的光晕中，随着月亮落下，光晕逐渐变暗，整个场景陷入黑暗之中。
Credit: Fabrizio Melandri/IAU OAE (CC BY 4.0)

Caption: 这段延时摄影视频捕捉到了来自世界不同角落的两个标志性星座，一段跨越了多个大陆的宇宙之旅正在展开。从中国开始，北斗七星在夜空中熠熠生辉，作为文化叙事中的坚定向导，它的光芒标志着这场漫长的天体征途的开始。北斗七星的勺口二星指向北极星，随着星空的旋转，北极星似乎保持静止不动。在尼泊尔的崇山峻岭中，北斗七星的熟悉感依然存在，在随着地球的自转而不断变化的全景中，它是一个可靠的锚点。来到智利，南十字星点缀着苍穹，象征着南半球的星空。来自智利的画面展现了银河系映衬下的南十字星。在纳米比亚，H.E.S.S.天文台的望远镜出现在视频中。随后，在遮天蔽日的大树下，北斗七星继续在天体中熠熠生辉，与满天繁星交相辉映。利用不同的技术——鱼眼镜头、静态相机和地球运动跟踪，每一帧画面都展现了南十字星在各种不同地景映衬下的壮丽景象。这些以星轨和地球自转为标志的序列，突出了北斗七星和南十字星的永恒存在，架起了跨越南北两个半球的桥梁，沟通了世界文化，连通了天体之美。
Credit: Jianfeng Dai/IAU OAE (CC BY 4.0)

Caption: 2022 年 3 月拍摄的这张照片中，北京故宫矗立在星轨编织的夜空芭蕾之下，见证着古老的天体之间的联系。紫禁城在设计时考虑到了宇宙的排列，呼应了北极星的方位，北极星又叫 Polaris，是长期以来指引航海者的天体之锚，象征着天空的稳定。人们相信皇帝是北极星在人间的化身，是连接天地的桥梁。在这张用智能手机拍摄的和谐的一小时曝光照片中，星星的轨迹描绘了它们夜间穿越苍穹的旅程，它们向北极星汇聚，体现了建筑设计和天体轨迹的精确性。
Credit: Stephanie Ziyi Ye/IAU OAE (CC BY 4.0)

Caption: The constellation Octans along with its bright stars and its surrounding constellations. Octans is surrounded by (going clockwise from the top): Hydrus, Indus, Pavo, Apus, Chameleon and Mensa. Octans is a relatively faint constellation that is notable as it lies at the south celestial pole. While the northern pole star is the relatively bright Polaris, sigma Octans, the southern pole star, is barely visible with the naked eye. Octans lies at the south celestial pole and is thus visible from the whole southern hemisphere with some of the constellation visible from equatorial regions of the northern hemisphere. The constellation is circumpolar for most of the southern hemisphere. It is best viewed in the evening in the northern hemisphere autumn and southern hemisphere spring. This diagram maps an area around the south celestial pole. Here lines of constant right ascension converge. The right ascension values of these lines (in hours) are marked on the x-axis above and below the diagram. The solid circle around the pole marks a line of -80° declination with the larger, incomplete circle to the right marking -70° declination. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

Caption: The constellation Ursa Minor along with its bright stars and its surrounding constellations. Ursa Minor is surrounded by (going clockwise from the top): Cephus, Camelopardalis and Draco. Ursa Minor is notable as its brightest star, Polaris is the northern pole star. Ursa Minor is visible from the entire northern hemisphere with some parts of the constellation being visible from equatorial regions of the southern hemisphere. It is also circumpolar for temperate and arctic regions of the northern hemisphere. Polaris, lying very close the north celestial pole is circumpolar for the whole of the northern hemisphere. The constellation is most visible in the evenings in the northern hemisphere summer and southern hemisphere winter. This diagram maps an area around the north celestial pole. Here lines of constant right ascension converge. The right ascension values (in hours) of these lines are marked on the x-axis above and below the diagram. Some of the lines of constant declination (in degrees) are marked on the y-axis. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope