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Glossary term: Southern Cross

Description: The Southern Cross is the common name for the southern hemisphere constellation Crux. It has five stars visible to the naked eye forming a long cross, is compact, and easily recognized. Crux covers the smallest area of the celestial sphere of any of the 88 official constellations. The brightest star, alpha Crucis is a triple star system whilst beta Crucis is a Cepheid variable. Crux also contains a stunning open cluster, the Jewel Box (NGC 4755). Crux can be used to help find south and the celestial South Pole. It is represented on the flags of Australia, Brazil, New Zealand, Papua New Guinea, and Samoa.

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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".

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The Southern Cross forms a kite shape in front of the mottled light and dark patches of the Milky Way.

Cen-Lup-Cru-Panorama: Centaurus Carrying the Beast and Riding Along the Milky Way

Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   This image was taken in February 2020 in the Coquimbo Region along the northern coast of Chile. It is one of the best places on Earth for astronomical observations, thanks to its clear skies, lack of light pollution and lack of precipitation, as it is close to the Atacama desert, one of the driest places on our planet. It is no coincidence that many of the most modern professional observatories are located here. The picture shows prominent patterns visible in the southern latitudes, containing rich cultural significance for various Indigenous groups of the southern world. In the bottom of the image towards the right, the Southern Cross is prominent. The orange star at the top of the Southern Cross is called Gacrux (gamma crux). The people in Chile celebrate the beginning of winter at the beginning of May when the constellation Crux is high up in the sky; for them it is a symbol of the start of the cold season. For the festival of the Cruz de Mayo (the Great Cross), they put candles next to crosses in their villages when the constellation Crux is high. As in Christianity, the four endpoints (stars) of the cross symbolise the cardinal virtues. For some indigenous Chileans, they represent the fundamental cultural principles: force, reciprocity, wisdom, and spirituality. Unlike modern constellations that are arrangements of several stars, Indigenous peoples sometimes associate stories with individual stars. In the case of the Southern Cross for example, the Boorong, Djab Wurrung and Jardwadjali peoples of Australia refer to the star Gacrux as Bunya (the ring-tailed possum). From the Southern Cross to the left of the image are two bright stars, these are called the pointer stars (as they point to the Southern Cross). The Djab Wurrung and Jardwadjali people refer to the pointer stars as the Bram-bram-bult brothers, who hunted and killed the giant Emu Tchingal. Alpha Centauri, which is the brighter and whiter of the two pointer stars, is the closest star to the Sun that we can see with our eyes, located just over four light-years away. To the bottom left of the Southern Cross is a dark nebula, which the Indigenous Australians see as the head of the Emu Tchnigal (the Coalsack Nebula). The pointers are located on the neck of the Emu. The image also shows two other IAU constellations, Centaurus (The Centaur) and Lupus (The Wolf), and HII regions of the Eta Carina Nebula (seen in pink).
Credit: Uwe Reichert/IAU OAE

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Over trees with thick trunks, the Milky Way, with several bright objects left and right, is bisected by a wide dark line.

Milky Way over Avenue of Baobabs

Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   This image, taken from the Avenue of Baobabs, Morondava, Madagascar, in July 2017, shows the majestic band of the Milky Way, our home galaxy, together with a rich collection of constellations and asterisms: Crux, Centaurus, Scorpius, Sagittarius and the Teapot asterism. Towards the bottom left of the image we can see the Southern Cross and the pointer stars Alpha (the brighter of the two) and Beta Centauri, which help to distinguish it from similar-looking configurations. Some cultures in Africa associate the Southern Cross with a giraffe, while others associate the constellations with a pride of lions or even with the Tree of Life. Antares, the brightest star in the constellation Scorpius, is the orange-red star straight up from the middle baobab tree. To the Pokomo people from southwestern Kenya, Africa, the Milky Way is associated with the smoke emanating from a campfire lit by ancient people. The various people in South Africa, in contrast, have different star tales; the Khoikhoi from the region around Cape Town explained the colours of the red and white stars as red and white roots that were roasted on a fire and thrown towards the sky together with the ashes of the fire. The Xhosa from further east consider the Milky Way the raised bristle of a huge angry dog, while the Zulu from near Johannesburg interpret it as a stream of spears of their strongest warriors. Polynesian people, who were adept seafarers and navigators, see the constellation Scorpius as a fish hook, and refer to it as the demigod Maui’s Fish Hook. For the Djab Wurrung and the Jardwadjali people, the Southern Cross is part of a Dreamtime Story involving Tchingal, the Bram-bram-bult brothers (the pointer stars), their mother Druk (Delta Crux), and Bunya, the hunter who gets changed into a possum (Gacrux, red star at the top of the Southern Cross). In this image, the planets Saturn (the bright point above Antares) and Jupiter (the bright point at the bottom-right of the image close to the trunk of the baobab tree) are visible. Indigenous cultures have various stories associated with the planets, for example Kamilaroi and Wailan people associate Saturn with wunygal, a small bird. The Boorong people of Western Victoria associate Jupiter with Ginabongbearp, the chief of the old spirits (Nurrumbunguttias), who takes the totemic form of the sulphur-crested white cockatoo.
Credit: Amirreza Kamkar/IAU OAE

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The Milky Way arches over an African grassland. Its diffuse glow is interrupted by a stream of dark patches.

Milky Way Arch over Amboseli National Park

Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   This image was taken in July 2016 from the Amboseli National Park in Kenya, located close to the equator. In Egyptian mythology from northern Africa, the Milky Way was associated with a river sailed by gods and souls. The Zulu in South Africa interpret this pattern of dark and bright clouds of stars as an animal with black and white skin, whereas the South African Khoikhoi and San considered it “The Star’s Road”. In several South African cultures, the arch of the Milky Way is a pathway to the heavens formed by a mother goddess, according to a South African creation myth that was adopted in the 19th century from early ethnological research, but has vanished today. In the middle-right of the image we find the bright red star Antares in the modern constellation of the Scorpion and at the upper-left edge is the white star Vega that is considered a Male Steenbok by the peoples around Cape Town. Indigenous Australians have many names for the Milky Way. The Yolnu people of Arnhem Land in Australia’s Northern Territory refer to the Milky Way as Milnguya, the sky river. One of the prominent patterns in this image is associated with the contrast between the light and dark regions of the Milky Way. These dark regions are cool dense clouds of interstellar dust and gas, which block the light from stars behind them. One of the prominent patterns is that of the Celestial Emu referred to as Tchingal by several Indigenous peoples of south Australia. The head and beak of the emu (the Coalsack Nebula) lie to the bottom-left of the Southern Cross (seen in the far bottom-right of the image), and the body and legs stretch leftward from it. Other indigenous groups associate the dark regions with caves or waterways. The orientation of the emu over the year provides important clues as to when it is time to pick emu eggs, and when the eggs are hatching. In some months, when these clouds of the Milky Way are close to the horizon, they are not considered as emu at all but as two creeping crocodiles. The modern figure of the dark Pipe Nebula is clearly visible above the centre of the Galaxy; the smoke of this pipe reaches the colourful rho Ophiuchi region next to Antares in Scorpius, the orange-red star just above the Milky Way. Antares is referred to by the Boorong people as Djuit, the red-rumped parrot, while the Kokatha people of the Western Desert refer to Antares as Kogolongo, the red-tailed black cockatoo. In addition, some notable constellations can be seen: Cygnus, Aquila, Lyra, Scorpius, Sagittarius, Crux, and Centaurus. The pointer stars, Alpha and Beta Centauri, are occasionally interpreted as The Eyes of the Beast in some South African traditions.
Credit: Amirreza Kamkar/IAU OAE

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The curve of the Milky Way over a road. Bottom left, two bright stars form a line pointing to a kite-shaped stellar assembly

Most Brightest Stars of the Sky

Caption: Honourable mention in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   Taken in March 2016 in Bromo-Tengger-Semeru National Park, Java Island, Indonesia, this image shows the arch of the Milky Way and many prominent constellations, including many of the brightest stars in the night sky. In the lower-left corner, we see Rigil Kentaurus and Hadar, the first one lower and the other higher up, both located in the large constellation Centaurus. As pointers they point towards Crux, the Southern Cross, whose long axis points towards the southern pole, which is located roughly at the horizon because the Island of Java is almost at the equator. Crux is almost entirely obscured by clouds, with only the four bright stars visible in the photograph. Confusingly, the asterism of the False Cross (consisting of stars in Argo, The Ship) is clearly prominent a bit further up the Milky Way. The pinkish spot between the true and the False Cross is the Carina Nebula, located about 8500 light-years from Earth, in the constellation Carina, and invisible to the unaided eye. In Carina we can also find Canopus, the second-brightest star in the night sky, seen just below the Galaxy and above the road on the ground. Even brighter is Sirius, the brightest star in the night sky. Sirius lies in the constellation Canis Major, The Great Dog, one of the dogs that follow Orion, the Hunter, who is depicted in the right half of this image, just above the clouds at the horizon. Orion’s Belt of three bright stars points to Sirius in the upper left and to Aldebaran in the lower right, just above the horizon. Orion contains some of the brightest stars in the sky, making it the most colourful constellation as it hosts Rigel, the bright bluish star below the Galaxy toward the right, and Betelgeuse, the reddish bright star higher up and to the right of Rigel. Between them we find the three stars that comprise the belt of Orion, a famous asterism. Just next to the belt we find the Great Orion Nebula, a star-forming region whose bright centre is visible to the unaided eye and also in this image. Above Betelgeuse but on the opposite side of the Galaxy, we see the bright star Procyon, whose name means literally “Before the Dog”. It is mythologically often considered a tiny one-star dog asterism accompanying Orion, and transformed into the modern constellation of Canis Minor. In the upper-right corner, the Beehive Star Cluster in the constellation Cancer is easily recognisable. Below it, we find the constellation Gemini with the stars Pollux and Castor, which are not prominent in this image. In contrast, the bright white star Capella in the constellation Auriga, the Charioteer, shines through the clouds at the middle-right edge of the image. Some light pollution is visible along the road.
Credit: Giorgia Hofer/IAU OAE

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The Milky Way over a cloudy landscape. A triangle of bright objects is visible on the left of the image.

Equatorial Milky Way

Caption: Honourable mention in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns: Equatorial Milky Way   Taken in Bromo-Tengger-Semeru National Park, Java Island, Indonesia, in March 2016, this image captures regions of the southern Milky Way and, at its left edge, the two planets Mars and Saturn. Mars appears orange and is similar in colour to the star Antares, whose Greek name — anti Ares — references this. Saturn is a little bit fainter than Mars, but clearly visible among the stars of Ophiuchus, above the Pipe Nebula and forming an isosceles triangle with Mars and Antares. Mars is on the top and Saturn is vertically below. Visible to the naked eye, both planets have significance in many cultures around the world. In Roman mythology Mars is the god of war and fertility, and Saturn the god of sowing and agriculture. Its Greek equivalent, the god Kronos, is also considered the regent of completion. Indigenous Australians, including the Kamilaroi and Wailan people, associate Saturn with “wunygal”, a small bird. Mars is called Iherm-penh (something burnt in flames) by the Anmatyerre people of the Central Desert, while the Kokatha people of the Western Desert associate Mars and the star Anatres with the red-tailed black cockatoo (Kogolongo). In the middle of this photograph, the most famous southern constellations are clearly recognisable: the Southern Cross (Crux), the pointer stars, Alpha and Beta Centauri, the dark Coalsack Nebula and the red Eta Carina Nebula, which is not visible to the unaided eye but is prominent in modern photographs. In the 19th century, the star eta Carinae had been the second-brightest star in the sky for some time, but since it varies irregularly, it has hardly been recognisable in recent decades, and its future visibility is unpredictable. Triangulum Australe is visible between the pointer stars and the Scorpion, and in the constellation of Centaurus, the bright globular star cluster Omega Centauri is clearly displayed. It was considered a “nebulous star” since antiquity and, thus, was listed in star catalogues for at least 2000 years. Only within the last century did astronomers discover that globular star clusters are in the halo of our galaxy and that this one consists of roughly 10 million stars. The dark regions in the Milky Way, which are cool, dense clouds of dust and gas, form the head and body of the Celestial Emu Tchingal. Together with the Southern Cross and the pointer stars, they appear in the Dreamtime stories of many Indigenous Australians. One story associated with the Djab Wurrung and the Jardwadjali people is part of a Dreamtime Story involving Tchingal, the Bram-bram-bult brothers (the pointer stars), their mother Druk (Delta Crux), and Bunya the hunter, who gets transformed into a possum (Gacrux, the red star at the top of the Southern Cross).
Credit: Giorgia Hofer/IAU OAE

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The curve of the Milky Way bisected on the left by a huge dark arch. Below appear two bright, diffuse patches.

The Milky Way Over Anglers Reach

Caption: Winner in the 2022 IAU OAE Astrophotography Contest, category Still images of celestial patterns.   The Milky Way and several astronomical objects are seen in this image taken from the southern hemisphere, in Anglers Reach, Australia, in April 2022. On the bottom-left side we can identify the constellation Scorpius with its brightest star, Antares, the reddish spot just above the arc. Some prominent but small southern constellations can also be seen: the dominating bright stars in the middle-left of the image in the Milky Way are the four bright stars of Crux (the Southern Cross) and to its left the two pointer stars, alpha and beta Centauri. Crux points towards the southern celestial pole, which is not marked by a bright star, and The pointer stars point towards Crux, distinguishing it from the asterism of the False Cross in the constellation Argo. Crux features on the national flags of Australia, Brazil, Papua New Guinea, Samoa and New Zealand. As Crux lies in the brightest parts of the Milky Way, the dark cloud of the famous Coalsack Nebula is prominent next to the bright stars. It forms one of the dark constellations in South American, South African and Australian indigenous cultures. The huge Australian dark constellation of the Emu is almost completely above the horizon in this image, stretching from its head in the Coal Sack to the horizon. In Greek antiquity, the stars of Crux also belonged to the constellation Centaurus, a hybrid creature with a human torso and head attached to a horse body with four legs. The Greek centaur represents Chiron, the wise teacher of all Greek heroes. Its brightest star is Rigil Kentaurus (Alpha Centauri), the front hoof of the centaur. Just below it, we find the small constellation Triangulum Australe. The triple star system of Alpha Centauri is our Sun’s nearest stellar neighbour. Along the Milky Way in the middle-right of the picture we find the huge constellation Argo, the Ship. The smaller ancient constellation Argo was extended by Dutch navigators around 1600, and the number of stars in this constellation was then so big that the 18th-century French mathematician Lacaille needed to introduce subtitles for Argo in his star catalogue. In doing so, he invented the constellations Puppis, Carina and Vela. In Carina, the Keel of the ship, this reddish photograph clearly displays the Carina Nebula. At the right edge of the image we can spot the brightest star in the night sky, Sirius, while the second brightest star, Canopus, the rudder of Argo, the Ship, dominates the area under the arch of the Milky Way. Also below the Milky Way arc, we can see the Large Magellanic Cloud and the Small Magellanic Cloud, which are small satellite galaxies of our own Galaxy.
Credit: Lucy Yunxi Hu/IAU OAE

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The Milky Way appears as a diagonal stripe bottom left to top right. It becomes more horizontal as the video progresses.

Southern Sky Over La Silla

Caption: This video shows the Milky Way’s sprawling brilliance across the celestial expanse. Among the stars’ grand theatre, the Southern Cross constellation claims its place in the scene, distinguished by its distinctive cross shape as seen in the top of this video and slightly to the right just over the Milky Way, slowly disappearing as the video progresses. This celestial marker, a prominent feature in the southern hemisphere, holds cultural and navigational significance, having served as a navigational guidepost for centuries. Accompanying the Milky Way’s grandeur are the two Magellanic clouds, celestial companions seen dancing in the distant sky. The Carina Nebula adds its ethereal glow to the cosmic panorama, painting a radiant hue against the darkness. In the midst of this celestial ballet, a gentle green hue envelops the atmosphere, a phenomenon known as airglow, adding a touch of subtle luminescence to the night sky. The terrestrial also makes an appearance, with planes flying overhead and vehicles driving between observatory buildings. This time-lapse, taken from the La Silla Observatory in Chile, is a window to the captivating dance of stars, offering a glimpse into the awe-inspiring beauty of our galaxy and the celestial landmarks that grace the southern sky.
Credit: José Rodrigues/IAU OAE (CC BY 4.0)

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The Southern Cross points out the South Celestial Pole, around which the sky appears to rotate

Beautiful Night in the Atacama Desert

Caption: Taken from San Pedro de Atacama, Chile, in June 2023, this time-lapse reveals the celestial ballet that unfolds as the Southern Cross takes its majestic journey across the sky, pointing the way to the South Celestial Pole around which the sky rotates, until it gracefully sets. The star-studded canvas showcases the grandeur of the Milky Way, adorned by the rotating Large and Small Magellanic Clouds swirling around the Southern Celestial Pole. The prominent constellations of Crux, Centaurus, Scorpius, and the former Argo Navis (Carina, Puppis, Vela) are also visible. The spectacle begins just after nightfall, capturing the radiant descent of Canopus, a beacon about to dip below the horizon. Throughout the sequence, there is a subtle presence of passing aeroplanes, fleeting headlights of cars, drifting clouds, and the ethereal airglow. At a stunning moment, a vivid meteor streaked across the sky, a breathtaking fireball briefly igniting the right lower corner around the 41st second mark. As the sequence progresses, the rising moon elegantly illuminates the landscape, casting its glow upon an ancient tree trunk resting on the dry, dusty grounds of the Salar de Atacama. This captivating journey through the night skies concludes before the break of dawn, offering a glimpse into the celestial marvels that are woven into the nocturnal tapestry of San Pedro de Atacama.
Credit: Uwe Reichert/IAU OAE (CC BY 4.0)

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Timelapses of rotating skies behind trees, telescopes, mountains and observatories

The Rotating Planet

Caption: A cosmic journey unfolds across continents in this time-lapse video which captures both iconic constellations from diverse corners of the world. Starting in China, the Big Dipper graces the night sky, a steadfast guide embedded in cultural narratives. Its luminance marks the beginning of this celestial odyssey. The two pointer stars on the end of the Big Dipper point to the North Star (Polaris) which appears to remain stationary as the sky rotates. From Nepal’s lofty peaks, the Big Dipper’s familiarity persists, a reliable fixture in the shifting panorama of the rotating planet. Moving to Chile, the Southern Cross adorns the firmament, emblematic of the southern skies. Frames from Chile showcase this constellation accompanied by the Milky Way Galaxy. In Namibia, a telescope from the H.E.S.S. Observatory appears in the video. Later, nestled beneath sheltering trees, the Big Dipper persists in its celestial prominence, appearing against a canvas of stars. Using varied techniques — fisheye lenses, static cameras, and Earth's movement-tracking — each frame unveils the Cross’s grandeur against diverse landscapes. These sequences — marked by star trails and Earth’s rotation—highlight the enduring presence of the Big Dipper and Southern Cross, bridging cultures and celestial beauty across hemispheres.
Credit: Jianfeng Dai/IAU OAE (CC BY 4.0)

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Related Diagrams


The four bright stars of Crux form a kite shape with the long axis pointing vertically

Crux Constellation Map

Caption: The constellation Crux (commonly known as the Southern Cross or Crux Australis) showing its bright stars and surrounding constellations. The Southern Cross is surrounding by (going clockwise from the top) Centaurus, Carina and Musca. The brightest star is alpha Crucis which appears at the bottom of the constellation's famous kite shape. The Southern Cross is visible from southern and equatorial regions of the world. In more southerly parts of the world it is circumpolar so is always above the horizon. In other parts of the southern hemisphere and in equatorial regions it is most visible in the evenings in the southern hemisphere autumn. The yellow circles show the locations of two open clusters, NGC 4755 (known as the Jewel Box) and NGC 4609. The line joining gamma and alpha Crucis (the third and first brightest stars in the Southern Cross) points in the approximate direction of the South Celestial Pole. This has led to the Southern Cross playing an important role in celestial navigation, allowing navigators from different astronomical traditions to find their bearings. 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.

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