Caption: Mention honorable au concours d'astrophotographie 2022 de l'UAI OAE, catégorie Images fixes de motifs célestes. Prise en mars 2016 dans le parc national de Bromo-Tengger-Semeru, sur l'île de Java, en Indonésie, cette image montre l'arc de la Voie lactée et de nombreuses constellations importantes, y compris la plupart des étoiles les plus brillantes du ciel nocturne. Dans le coin inférieur gauche, nous voyons alpha et bêta du Centaure, le premier plus bas et l'autre plus haut, tous deux situés dans la grande constellation du Centaure. Ils pointent vers la Croix du Sud, dont le grand axe pointe vers le pôle sud, qui se trouve à peu près à l'horizon car l'île de Java est presque à l'équateur. La Croix du Sud est presque entièrement obscurcie par les nuages, et seules les quatre étoiles brillantes sont visibles sur la photo. L'astérisme de la fausse croix (composé des étoiles d'Argo, le navire) est clairement visible un peu plus loin dans la Voie lactée, ce qui peut prêter à confusion. La tache rosée entre la vraie et la fausse croix est la nébuleuse de la Carène, située à environ 8500 années-lumière de la Terre, dans la constellation de la Carène, et invisible à l'œil nu. Dans la constellation de la Carène se trouve également Canopus, la deuxième étoile la plus brillante du ciel nocturne, visible juste en dessous de la galaxie et au-dessus de la route au sol. Sirius, l'étoile la plus brillante du ciel nocturne, est encore plus brillante. Sirius se trouve dans la constellation Canis Major, le Grand Chien, l'un des chiens qui suivent Orion, le Chasseur, représenté dans la moitié droite de cette image, juste au-dessus des nuages à l'horizon. La ceinture d'Orion, composée de trois étoiles brillantes, pointe vers Sirius en haut à gauche et vers Aldébaran en bas à droite, juste au-dessus de l'horizon. Orion contient certaines des étoiles les plus brillantes du ciel, ce qui en fait la constellation la plus colorée, car elle abrite Rigel, l'étoile bleuâtre brillante située sous la galaxie vers la droite, et Bételgeuse, l'étoile rougeâtre brillante située plus haut et à droite de Rigel. Entre elles se trouvent les trois étoiles qui forment la ceinture d'Orion, un astérisme célèbre. Juste à côté de la ceinture se trouve la Grande Nébuleuse d'Orion, une région de formation d'étoiles dont le centre brillant est visible à l'œil nu et également sur cette image. Au-dessus de Bételgeuse, mais de l'autre côté de la galaxie, nous voyons l'étoile brillante Procyon, dont le nom signifie littéralement "Avant le chien". D'un point de vue mythologique, elle est souvent considérée comme un petit astérisme à une étoile accompagnant Orion, et transformé en la constellation moderne de Canis Minor. Dans le coin supérieur droit, l'amas d'étoiles de la Ruche, dans la constellation du Cancer, est facilement reconnaissable. En dessous, on trouve la constellation des Gémeaux avec les étoiles Pollux et Castor, qui ne sont pas très visibles sur cette image. En revanche, la brillante étoile blanche Capella de la constellation du Cocher, le Chariot, brille à travers les nuages au milieu à droite de l'image. Une certaine pollution lumineuse est visible le long de la route.
Credit: Giorgia Hofer/IAU OAE

Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   Taken in Romania in August 2012, this image shows two of the most recognisable constellations in the sky, Orion and Taurus. Orion, the Hunter, is found near the horizon. The most prominent star visible in this image is Betelgeuse, while the asterism of Orion’s belt is formed by three aligned bright stars. Just above Orion we can find Taurus, one of the constellations of the Zodiac. As the Zodiac is inherited from Babylon, The Bull of Heaven represents a mighty but dangerous creature that was defeated by King Gilgamesh and his friend Enkidu. They cut the Bull in half and sacrificed the animal to the gods in order to protect their people. Taurus is also home to the star cluster Pleiades, also known as the Seven Sisters. Two planets are visible: Venus, the bright spot near the fence, and Jupiter, the bright spot at the top, next to the Bull’s face. Different cultures have included the stars of these constellations in their own mythology. The Romanians, for instance, after Christianisation identified four other constellations using some of the stars of Orion and others surrounding it. One such constellation is called Trisfetitele (the Three Saints), which is associated with the three stars comprising Orion's Belt, representing the Three Hierarchs Basil, Gregory and John. This same asterism is also called Three Wise Men, Kings from the East or just Three Kings — all of these names being rooted in the Christian religion. The agricultural calendar, in contrast, led farmers to define two other constellations, the Little Plough and the Sickle. Both are seen in the southern half of the Orion rectangle; the Little Plough is drawn by connecting the southern quadrilateral with Orion’s left shoulder, and the Sickle is formed by connecting Orion’s left foot (Rigel) with the belt stars, forming an arch and completing the form of a hoe. In the cultural calendar, these constellations were used to announce the harvest of wheat/grain. Finally, the fourth Romanian constellation is the Great Auger, where Orion’s belt represents the handle of the auger, and Betelgeuse is the tip, facing towards Pollux in Gemini. This constellation is associated with treasure, as Romanian peasants believe that the Auger points to the treasure when they approach the end of the world. Most of the official star names in Orion are Arabic; Mintaka (meaning “belt”) is at the waist; Alnitak (meaning “girdle”) and Alnilam (meaning “string”) are at the belt; and Rigel (meaning foot) is at the left foot. The star on the left shoulder is named Bellatrix, the Latin term for a female warrior. The star at the right leg is called Saiph, for the sword or sabre of the Arabic Orion.
Credit: Alex Conu/IAU OAE

Caption: Photographié avec un smartphone le 13 décembre 2022, un météore des Géminides a illuminé le ciel au-dessus de la Vallée de la Lune Bleue, Yunnan, en Chine, offrant un spectacle à couper le souffle sur fond de sérénité de la Montagne des Neiges du Dragon de Jade. Réputées pour leur luminosité éblouissante et leurs teintes vives, les Géminides font partie des pluies de météores les plus vibrantes provenant de l'astéroïde 3200 Phaethon. Chaque année, lorsque notre planète traverse la traînée de débris de Phaethon, des fragments de poussière et de roche se vaporisent dans l'atmosphère, créant le phénomène stupéfiant de la pluie de météores des Géminides. Sur cette superbe image du ciel nocturne, les étoiles jumelles des Gémeaux (Castor et Pollux) sont masquées par la silhouette des arbres à gauche. Dans les eaux calmes se reflètent les étoiles de la constellation d'Orion, que l'on voit s'élever vers le centre inférieur de l'image, tandis que Mars, radieuse, conserve son éclat en tant que premier phare céleste de la scène, avant que le lever de la lune ne prenne le relais.
Credit: Jianfeng Dai/IAU OAE (CC BY 4.0)

Caption: The constellation Orion along with its bright stars and surrounding constellations. Orion is surrounded by (going clockwise from the top) Taurus, Eridanus, Lepus, Monoceros and Gemini. Orion’s brightest stars Betelgeuse and Rigel appear at the northern (upper on this diagram) and southern (lower) end of the constellation respectively with the famous three star “belt” in the middle. Orion spans the celestial equator and is thus visible at some time in the year from all of planet Earth. In the most arctic or antarctic regions of the world, some parts of the constellation may not be visible. Orion is most visible in the evenings in the northern hemisphere winter and southern hemisphere summer. The blue line above Orion marks the ecliptic, the path the Sun appears to travel across the sky over the course of a year. The Sun never passes through Orion, but one can occasionally find the other planets of the Solar System and the Moon in Orion. Just south of Orion’s belt lie two Messier objects M42 (the Orion nebula) and M43, marked by green squares. These nebulae along with M78 (here the green square to the left of the belt) are part of the huge Orion Molecular Cloud Complex. This covers most of the constellation and includes regions where these molecular clouds are collapsing to form young starts. The y-axis of this diagram is in degrees of declination and with north as up and the x-axis is in hours of right ascension with east to the left. 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 circle around Betelgeuse indicates that it is a variable star. 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 Taurus along with its bright stars and surrounding constellations. Taurus is surrounded by (going clockwise from the top) Perseus, Aries, Cetus, Eridanus, Orion, Gemini and Auriga. Taurus’s brightest star Aldebaran appears in the middle of the constellation. Taurus lies on the ecliptic (shown here as a blue line), this is the path the Sun appears to take across the sky over the course of a year. The Sun is in Taurus from mid May to late June. The other planets of the Solar System can often be found in Taurus. Taurus lies mostly north of the celestial equator with a small part in the celestial southern hemisphere. The whole constellation is visible at some point in the year to whole planet except for the Antarctic and a small region around the North Pole. Taurus is most visible in the evenings in the northern hemisphere winter and southern hemisphere summer. In the eastern part of Taurus we can find the supernova remnant M1 (commonly known as the Crab Nebula), marked here with a green square. In Taurus’s north-east find one of the sky’s most famous open stars clusters M45 (the Pleiades), marked here with a yellow circle. Many of the stars near Aldebaran (but not) Aldebaran are members of another star cluster, the Hyades. However this cluster is close to the solar system so is too dispersed on the sky to have a Messier object designation like the Pleiades has. The y-axis of this diagram is in degrees of declination and with north as up and the x-axis is in hours of right ascension with east to the left. 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 zodiac constellation Cancer and its surrounding constellations. Starting from the top of the diagram and going clockwise, these are Lynx, Gemini, Canis Minor, Hydra, Leo and Leo Minor. The ecliptic (shown here as a blue line) passes almost exactly through the middle of the constellation, this is the path the Sun appears to take across the sky over the course of a year. The Sun is in Cancer from late July to mid August. The other planets of the Solar System can often be found in Cancer. Cancer lies just north of the celestial equator and is thus visible at some time in the year from all of planet Earth except for the most antarctic regions of the world. Cancer is most visible in the evenings in the northern hemisphere spring and southern hemisphere autumn. Two star clusters are visible in Cancer: M44, an open cluster often called the Beehive Cluster, and M46, a denser open cluster with about four times more stars than M44. These clusters are indicated by yellow circles with a dotted border on the map. The y-axis of this diagram is in degrees of declination and with north as up and the x-axis is in hours of right ascension with east to the left. 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 labelled 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