The Northern Cross is an astronomical asterism in the northern hemisphere of the

celestial sphere In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, ...

, corresponding closely with the constellation Cygnus the swan. It is much larger than the

Southern Cross CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system to ...

and consists of the brightest stars in Cygnus:

Deneb Deneb () is a blue supergiant star in the constellation of Cygnus. It is the brightest star in the constellation and the 19th brightest in the night sky, with an apparent magnitude slightly varying between +1.21 and +1.29. Deneb is one ...

, Sadr, Gienah,

Delta Cygni Delta Cygni is a binary star of a combined third-magnitude in the constellation of Cygnus (constellation), Cygnus. It is also part of the Northern Cross (asterism), Northern Cross Asterism (astronomy), asterism whose brightest star is D ...

and Albireo. The 'head' of the cross, Deneb, is also part of the

Summer Triangle The Summer Triangle is an astronomical asterism in the northern celestial hemisphere. The defining vertices of this imaginary triangle are at Altair, Deneb, and Vega, each of which is the brightest star of its constellation ( Aquila, Cygn ...

asterism. Like the Summer Triangle, the Northern Cross is an indicator of the seasons. Near midnight, the Cross lies virtually overhead at mid-northern

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

s during the summer months; it can also be seen during spring in the early morning to the East. In

autumn Autumn, also known as fall (especially in US & Canada), is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September (Northern Hemisphere) or March ( Southern Hemisphe ...

the cross is visible in the evening to the West until November. It never dips below the horizon at or above 45° north latitude, just grazing the northern horizon at its lowest point at such locations as

Minneapolis Minneapolis is a city in Hennepin County, Minnesota, United States, and its county seat. With a population of 429,954 as of the 2020 United States census, 2020 census, it is the state's List of cities in Minnesota, most populous city. Locat ...

Montréal Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...

and

Turin Turin ( , ; ; , then ) is a city and an important business and cultural centre in northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The city is main ...

. From the southern hemisphere it appears upside down and low in the sky during the

winter Winter is the coldest and darkest season of the year in temperate and polar climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Dif ...

months. In his Sixth Century guide to using the stars for monastic timekeeping, Bishop

Gregory of Tours Gregory of Tours (born ; 30 November – 17 November 594 AD) was a Gallo-Roman historian and Bishop of Tours during the Merovingian period and is known as the "father of French history". He was a prelate in the Merovingian kingdom, encom ...

described a constellation which he called the Greater Cross, which can be identified with stars of the constellation Cygnus. Below the cross he placed lesser constellations which he called Alpha and Omega, which can be identified with part of

Delphinus Delphinus is a small constellation in the Northern Celestial Hemisphere, close to the celestial equator. Its name is the Latin version for the Greek word for dolphin (). It is one of the 48 constellations listed by the 2nd-century astronomer Pt ...

and

Lyra , from ; pronounced: ) is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star ...

. This reflects early medieval iconography, in which a cross is depicted with the letters Alpha and Omega below the arms of the cross. In

Johann Bayer Johann Bayer (; 1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain in 1572. In 1592, aged 20, he began his study of philosophy and law at the University of Ingolstadt, after which he ...

's 17th-century star atlas, the ''Uranometria'', it was suggested that Alpha, Beta and Gamma Cygni formed the pole of the

Christian Cross The Christian cross, seen as representing the crucifixion of Jesus, is a religious symbol, symbol of Christianity. It is related to the crucifix, a cross that includes a ''corpus'' (a representation of Jesus' body, usually three-dimensional) a ...

, while Delta and Epsilon formed the cross beam. The

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are ...

P Cygni P Cygni (34 Cygni) is a variable star in the constellation Cygnus. The designation "P" was originally assigned by Johann Bayer in '' Uranometria'' as a nova. Located about 5,300 light-years (1,560 parsecs) from Earth, it is a hypergian ...

was then considered to be the body of Christ.

Member stars

References

{{Reflist, refs=

External links

Northern Cross: Backbone of Milky Way at EarthSky.orgNorthern Cross: Stars, Constellation, Facts, Myth at Constellation-Guide.com
Asterisms (astronomy) Cygnus (constellation)

Member stars

See also

References

External links