The constellations in tonight’s sky host many familiar star patterns. For northern observers, autumn is the best time of the year to see the Northern Cross in Cygnus and the Great Square of Pegasus. These two bright, large asterisms dominate the evening sky.
For observers in the southern hemisphere, the zodiac constellations Sagittarius and Capricornus are high overhead in the evening, as are the Southern Birds, Phoenix, Grus, Tucana, and Pavo.
The night sky tonight looks different depending on the location. The constellation maps below show the sky at around 10 pm in the mid-northern, equatorial, and mid-southern latitudes.
From locations in the mid-northern latitudes, the Northern Cross appears high overhead in the evening. The cross-shaped asterism is formed by the five brightest stars in the constellation Cygnus (the Swan). All five stars have evolved away from the main sequence and entered the final stages of their life cycles.
The supergiant Deneb sits at the top of the Northern Cross and marks the celestial Swan’s tail. It is part of the brighter and larger Summer Triangle asterism, which it forms with the brighter Vega in the constellation Lyra and Altair in Aquila.
Sadr, another supergiant, lies at the centre of the Cross. It is surrounded by a large diffuse nebula known as Sadr Region or the Gamma Cygni Nebula (IC 1318). Albireo, the faintest of the five stars, marks the bottom of the Northern Cross. It is an orange bright giant that forms a striking contrasting visual double star with its hot blue neighbour Albireo B.
Aljanah and Fawaris, the stars that mark the Swan’s wings, outline the beam of the Northern Cross with Sadr. Aljanah is an orange giant 72.7 light-years away, and Fawaris is a more luminous A-type subgiant 165 light-years away.
The constellation Pegasus is also high above the horizon around 10 pm. It is easily recognizable for the Great Square of Pegasus, a conspicuous asterism that dominates the eastern sky in the early evening and makes its way across the sky during the night. The Square of Pegasus is formed by three bright stars in Pegasus – Algenib, Scheat, and Markab – with Alpheratz in the neighbouring constellation Andromeda.
The zodiac constellations Aries and Pisces rise in the east in the evening. Both constellations can be found using the bright stars of Pegasus and Andromeda.
The Circlet of Pisces is the most recognizable feature of the constellation Pisces. It represents the head of the western fish and appears southeast of the Square of Pegasus. The head of the fainter eastern fish is found near Mirach, the central star in the chain of three bright stars that makes Andromeda easy to identify.
Mirach is commonly used to find two exceptionally bright galaxies: the Andromeda Galaxy (M31) and the Triangulum Galaxy (M33). The latter lies in the small constellation Triangulum, located between Andromeda and the flat triangle formed by the brightest stars of Aries.
The bright Perseus and Auriga rise in the northeastern sky in the evening and are followed by Taurus. Cetus, the fourth largest constellation in the sky, appears on the horizon, directly below Pisces, and fully rises later in the evening.
The northern evening sky is populated by several circumpolar constellations: Ursa Minor, Ursa Major, Draco, Camelopardalis, and Cassiopeia. Ursa Minor, the Smaller Bear, appears directly north, with the handle of the Little Dipper parallel to the horizon. Polaris, the bright star at the end of the Little Dipper’s handle, marks true north.
Ursa Major, the Great Bear, appears close to the horizon in the evening. Its seven bright stars form the Big Dipper, an asterism that can be used to find Polaris and the Little Dipper, as well as many other constellations in the vicinity. Polaris is found by extending a line from the two outer stars of the Big Dipper’s bowl to the north.
The tail of Draco is found between the Big and Little Dippers. The rest of the celestial Dragon winds around the Little Dipper’s bowl in the direction of Hercules and Cygnus.
The faint constellation Canes Venatici (the Hunting Dogs) appears directly below the Big Dipper’s handle. The even fainter Camelopardalis lies between Polaris, Capella, and Mirfak. Lynx can be seen between the head of the Great Bear and Auriga’s hexagon in exceptionally good conditions.
The W of Cassiopeia appears high above the horizon in the evening at this time of the year. The asterism can be used to find the fainter constellation figure of Cepheus, which appears above the W.
The constellations setting in the west around 10 pm include Hercules, Corona Borealis, Boötes, Ophiuchus, and Serpens.
Lyra with the bright Vega appears high in the western sky. Vega can be used to find the fainter stars of Hercules. The Keystone, the most identifiable part of Hercules, lies between Lyra’s luminary and the semi-circle of Corona Borealis, the Northern Crown. The asterism outlines the torso of Hercules and can be used to find the bright globular clusters M13 and M92.
Representing the crown of Ariadne in Greek mythology, Corona Borealis is found along the line of the Great Bear’s tail. Its brightest star Alphecca (Gemma) represents the jewel in the crown.
The Kite of Boötes begins to set below the horizon around 10 pm. Depending on the geography, Arcturus may or may not be visible. The red giant is the brightest star in the northern celestial hemisphere. It sits at the base of the Kite and is found along the imaginary line curving away from the Big Dipper’s handle.
Ophiuchus, the Serpent Bearer, and Serpens are large but relatively inconspicuous. Ophiuchus is the 11th largest constellation in the sky. It divides Serpens into two parts: Serpens Caput (the Serpent’s Head) and Serpens Cauda (the Serpent’s Tail). Rasalhague, the brightest star in Ophiuchus, shines at magnitude 2.07, while Unukalhai, the luminary of Serpens, has a visual magnitude of 2.623.
Ophiuchus is recognizable because its brightest stars form a large polygon that occupies much of the space between Hercules and Scorpius. Serpens is less conspicuous. Its head lies between Corona Borealis and Ophiuchus and its tail stretches on the other side of the polygon, in the direction of Aquila (the Eagle).
Most constellations appearing above the southern horizon in the evening are relatively faint. Piscis Austrinus (the Southern Fish) can be found using the bright stars of the Great Square of Pegasus. The imaginary line extended through the rightmost stars of the Square across the sky leads to Fomalhaut, the star marking the mouth of the Southern Fish. Fomalhaut is the 18th brightest star in the sky, but the rest of the Southern Fish is much fainter.
The faint V of Capricornus can be found using the Shaft of Aquila, an asterism formed by Altair with its neighbours Alshain and Tarazed. The line of the three stars points toward the right side of the V-shaped figure.
Aquarius can be identified by the Water Jar, a Y-shaped asterism appearing below the imaginary line connecting the southwest corner of the Square of Pegasus and Enif, the brightest star in Pegasus. The faint stars that represent the water flowing from the Water Jar toward the mouth of the Southern Fish (Fomalhaut) are visible on a clear night.
The bright Sagittarius sets in the southwest at this time of the year. The Teapot, a pattern formed by the constellation’s brightest stars, lies in a rich Milky Way field and can be used to find the many deep sky objects located in this region of the sky. These include the Lagoon Nebula (M8), Trifid Nebula (M20), and Omega Nebula (M17) in Sagittarius, and the Eagle Nebula (M16) in Serpens.
Observers in equatorial latitudes see many of the same constellations as those in mid-northern locations, but these constellations do not appear in the same place. Additionally, observers near the equator can see many constellations in the southern sky that are invisible to northern observers.
Pegasus, Aquarius, and Capricornus appear high overhead in the evening. The zodiac constellations are relatively faint and hard to spot from urban areas.
The brightest stars in the three constellations – the supergiants Sadalsuud (Beta Aquarii) and Sadalmelik (Alpha Aquarii) in Aquarius, the giant Deneb Algedi (Delta Capricorni) in Capricornus, and the supergiant Enif (Epsilon Pegasi) in Pegasus – form an asterism called the Lightning Bolt. The zig-zag pattern begins with Enif near the Great Square of Pegasus and ends with Deneb Algedi in Capricornus. It makes it easy to identify the luminaries of the two fainter constellations.
Cepheus, the King, lies directly north around 10 pm. The constellation is easy to recognize because its brightest stars form the pattern of a stick house that appears just above the brighter W of Cassiopeia.
Cassiopeia, the Queen, and Perseus appear east of Cepheus. Both constellations contain bright asterisms that make them easy to identify. The brightest stars of Cassiopeia form a W in the sky and Perseus is dominated by a pattern called the Segment of Perseus, which includes Mirfak, the constellation’s brightest star.
The faint Lacerta (the Lizard) is visible between Cepheus and Pegasus on a clear night. Draco, Hercules, and the constellations of the Summer Triangle (Lyra, Aquila, and Cygnus) appear in the northwest.
The most prominent constellation rising in the east around 10 pm is Cetus, the fourth largest constellation in the sky. Representing the Sea Monster from the myth of Andromeda in Greek mythology, Cetus occupies much of the space between Pisces and Eridanus. Its brightest stars, the orange giant Diphda (Beta Ceti) and red giant Menkar (Alpha Ceti), lie at opposite ends of the constellation. Menkar appears in the Sea Monster’s head and Diphda in its tail.
Eridanus, the sixth largest of the 88 modern constellations, represents the celestial River. It stretches from Rigel in Orion all the way to the far southern sky, where Achernar, the ninth brightest star in the sky, marks its end.
Pisces appears higher in the sky. It can be found using the Square of Pegasus and the chain formed by the three brightest stars in Andromeda.
The constellations setting directly west in the evening are Ophiuchus and Serpens. Rasalhague, the brightest star in Ophiuchus, can be found about halfway between Vega in Lyra and Antares in Scorpius. Rasalhague marks the head of Ophiuchus and is the northernmost star in the large polygonal constellation figure of the Serpent Bearer.
The Serpent’s head, which has fallen below the horizon by 10 pm, lies between Corona Borealis and the Scorpion’s claws, and its tail is found in the area between Antares and Altair.
The bright zodiac constellations Sagittarius and Scorpius are visible in the southwestern sky. They are easy to identify because they are dominated by prominent asterisms, the Teapot in Sagittarius and the Fish Hook in Scorpius.
The constellations are popular targets for backyard astronomers because they are home to some of the best-known nebulae and star clusters in the sky. Sagittarius hosts the Lagoon Nebula, the Trifid Nebula, the Omega Nebula, the globular cluster Messier 22 (the Sagittarius Cluster), and the open cluster Messier 25, while Scorpius contains the bright open clusters Messier 6 (the Butterfly Cluster) and Messier 7 (Ptolemy’s Cluster). Scorpius is also home to the red supergiant Antares, the 15th brightest star in the sky.
The fainter Scutum, the home of the Wild Duck Cluster (Messier 11), lies between the Teapot and the tail of Aquila (the Eagle). Aquila, recognizable for its bird-like pattern, hosts Altair, the 12th brightest star in the sky. Altair forms an asterism known as the Shaft of Aquila (or Family of Aquila) with the two fainter stars flanking it, Alshain and Tarazed. It is also part of the larger Summer Triangle along with Deneb and Vega. The Summer Triangle is visible high in the northwestern sky in the evening.
The southern evening sky is dominated by the Southern Birds, Grus (the Crane), Phoenix (the Phoenix), Tucana (the Toucan), and Pavo (the Peacock). The constellations are not particularly conspicuous but three of them host navigational stars. Grus is home to the hot blue main sequence star Alnair (Alpha Gruis), Pavo contains the hotter and more luminous Peacock (Alpha Pavonis), and Phoenix hosts the orange giant Ankaa (Alpha Phoenicis).
Achernar, another exceptionally hot and luminous navigational star, marks the southern end of Eridanus (the River) in the southeastern sky. The faint Octans, the home to Polaris Australis (the South Star) and the south celestial pole, appears directly above the southern horizon.
The constellations that appear high overhead around 10 pm for observers in the southern hemisphere are Capricornus, Sagittarius, Piscis Austrinus, Grus, Indus, and Microscopium.
Piscis Austrinus, the Southern Fish, is the only one of these constellations that contains a first-magnitude star. Fomalhaut, the constellation’s luminary, is an A-type main sequence star that shines at magnitude 1.16 from a distance of 25.13 light-years. It is one of the hottest stars in the solar neighbourhood. It has a circumstellar disk of dust that has earned it the nickname the Eye of Sauron. Fomalhaut is the brightest star along the imaginary line extended from the western side of the Great Square of Pegasus.
The bright stars of Sagittarius form the Teapot, an asterism that appears on the Milky Way’s band. On a very clear night, the Milky Way appears as steam coming from the Teapot.
The neighbouring zodiac constellation Capricornus is much fainter. Its main star pattern is a large faint V that appears roughly halfway between the Square of Pegasus and the Fish Hook of Scorpius.
The southern constellations Grus (the Crane) and Indus (the Indian) appear high above the horizon in the evening. Grus was once considered to be part of Piscis Austrinus and can be found directly south of Fomalhaut. It is home to Alnair, one of the 58 bright stars selected for use in celestial navigation.
The fainter Indus appears west of Grus, near the feet of the Archer. Its brightest star, Alpha Indi (the Persian), is an orange giant with an apparent magnitude of 3.11. The constellation also hosts Epsilon Indi, one of the nearest visible stars to Earth. The star lies only 11.867 light-years away.
Microscopium, one of the smallest and faintest constellations in the sky, is found between Indus and Capricornus. The constellation’s brightest star, the variable yellow giant Gamma Microscopii, shines at magnitude 4.68 and is a challenging target from light-polluted areas.
The constellations of the Summer Triangle are visible in the northern and northwestern sky from most locations in the southern hemisphere in the evening. Aquila (the Eagle) with the bright Altair appears higher in the northwestern sky while Cygnus (the Swan) with the supergiant Deneb and Lyra with the bright Vega stay close to the horizon. The Northern Cross in Cygnus appears upside down. Albireo, the visual double star at the bottom of the Cross, can be used to find the smaller and fainter Vulpecula (the Fox), the home of the Dumbbell Nebula (Messier 27).
The small but distinctive Sagitta (the Arrow) and Delphinus (the Dolphin) appear in the same area of the sky, between the Swan’s wing and the Eagle’s head.
The brighter and larger constellation Pegasus appears in the northeastern sky. The constellation’s luminary, the supergiant Enif, can be used to find the fainter Equuleus (the Little Horse), which lies between Enif and Aquila’s wing.
Pegasus is dominated by the Great Square asterism, formed by three bright Pegasus stars – Markab (Alpha Pegasi), Scheat (Beta Pegasi), and Algenib (Gamma Pegasi) with Alpheratz (Alpha Andromedae), the brightest star in the neighbouring constellation Andromeda.
The Square of Pegasus and the bright stars of Andromeda can be used to find the Great Pegasus Cluster (Messier 15), the Andromeda Galaxy (Messier 31), and the Triangulum Galaxy (Messier 33). The Pegasus stars also make it easy to find the Circlet of Pisces, an asterism outlining the head of the western fish in Pisces constellation, as well as the Water Jar, a Y-shaped pattern representing the water jar held by Aquarius, the Water Bearer.
The eastern sky is dominated by several large but not particularly distinctive constellations. Pisces, the 14th largest constellation in the sky, appears in the northeast. The head of the western fish is high in the sky, while the eastern fish is close to the horizon around 10 pm.
Cetus, the fourth largest of the 88 modern constellations, lies directly east. Its luminary Diphda is found along the imaginary line extended from the Great Square of Pegasus. Traditionally known as Deneb Kaitos (the tail of the Sea Monster), the orange giant star is part of Cetus’ tail. The head of Cetus is outlined by the red giant Menkar, the constellation’s second brightest star, and several fainter stars.
The famous pulsating variable red giant Mira (Omicron Ceti) lies in the neck of the Sea Monster. The bright barred spiral galaxy Messier 77, sometimes called the Squid Galaxy, appears roughly halfway between Mira and Menkar.
The faint Sculptor, the home to the famous Sculptor Galaxy (NGC 253), appears above Cetus. Its brightest star, the variable blue giant Alpha Sculptoris, has an apparent magnitude of 4.3.
Eridanus, the sixth largest constellation in the sky, occupies much of the southeastern sky. No other constellation extends as far in the sky from north to south. Achernar, the brightest star in Eridanus and the ninth brightest star in the sky, marks the constellation’s southern end.
The most prominent constellations in the western sky in the evening are Scorpius and Ophiuchus. Scorpius is one of the most distinctive constellations in the sky. Antares, Shaula and its other bright stars form an asterism known as the Fish Hook. Antares connects the Fish Hook and the Scorpion’s claws, which extend in the direction of the fainter Libra.
Ophiuchus, the 11th largest constellation in the sky, is dominated by a large polygon that splits the fainter Serpens constellation into two parts. The constellation is known for its hot blue stars Rho and Zeta Ophiuchi, as well as for its many bright globular clusters. Those listed in the Messier catalogue include Messier 10, Messier 14, Messier 19, and Messier 107.
The bright Centaurus, the ninth largest constellation in the sky, and the fainter, smaller Lupus (the Wolf) appear in the southwestern sky. Lupus lies between the Scorpion’s claws and the forefeet of the Centaur, represented by the Southern Pointers, Rigil Kentaurus and Hadar (Alpha and Beta Centauri).
Alpha and Beta Centauri point at Gacrux, the star at the top of the Southern Cross. The Southern Cross is formed by the brightest stars of Crux, the smallest constellation in the sky. It appears in the southern-southeastern sky.
Crux is commonly used to find the south celestial pole, which lies just south of the constellation figure of Octans. The South Star, Sigma Octantis, is too faint to be useful in navigation so the bright stars of Crux, Centaurus and Eridanus are used as guides to true south instead. The south celestial pole appears roughly halfway between Hadar and Achernar, near the imaginary line extended through the Southern Cross.
Most constellations appearing directly south are small, faint, and mostly invisible from urban areas. Hydrus, Chamaeleon, and Musca occupy the region between the bright Achernar in Eridanus and Acrux in Crux, while Reticulum, Horologium, Dorado, and Pictor are found between Achernar and Canopus. Volans lies between Canopus and Miaplacidus, the two brightest stars in Carina.
Carina appears low in the southern sky. It is one of the three constellations that formed Argo Navis (the Ship Argo), once the largest constellation in the sky. Carina represents the keel of Argo, while the neighbouring Vela and Puppis outline the sails and stern of the mythical ship.
Canopus, the brightest star in Carina, is the second brightest star in the sky, after Sirius. The bright giant shines at magnitude -0.74 from a distance of 310 light years. Miaplacidus, a white giant, is the 28th brightest star in the sky, and the orange giant Avior is the 40th. All three stars are selected for use in navigation.
Avior is part of the False Cross, an asterism often mistaken for the Southern Cross, while Miaplacidus is one of the stars of the Diamond Cross, a fainter asterism that appears similar to the other two. The true Southern Cross is easily identified as the brightest of the three asterisms that has a fifth star near the centre and two first-magnitude stars (Alpha and Beta Centauri) pointing at it.