Constellations > Compass

The compass is a constellation that is located in the southern sky and displays a marine navigation device.

It is one of the constellations created in the 18th century by Nicolas Louis de Lacaille. From the beginning he called it “Pyxis Nautica”, but later shortened to “Compass”. It was formerly part of the largest constellation Argo Ship.

It includes several interesting objects, including the planetary nebula NGC 2818, the open cluster NGC 2627 and the barred spiral galaxy NGC 2613.

Constellation compass

An objectDesignationMeaning of the nameObject typeMagnitude
1Alpha CompassNoBlue giant3.68
2Beta CompassNoYellow supergiant3.95
3Compass GammaNoOrange giant4.03
4Compass KappaNoMultiple star system4.62
5Lambda CompassNoYellow giant4.71
6Theta CompassNoRed giant4.72
7Zeta CompassNoMultiple star system4.86
eightDelta CompassNoMultiple star system4.87

Facts, position and map

With an area of ​​221 square degrees, the constellation Compass is the 65th largest constellation. Covers the second quadrant of the southern hemisphere (SQ2). Can be found at latitudes between + 50 ° and -90 °. Adjacent to Sails, Hydra, Feed and Pump.

Lat. titlePyxis
Right ascensionfrom 8h 22m up to 9h 22m
Declinationfrom -36 ° 45 to -17
Square221 sq. degrees
(65th place)
The brightest stars
(value <3m)
  • No; the brightest
    α Pyx – 3.68m
Meteor showers
  • No
Nearby constellations
  • Hydra
  • Stern
  • Pump
  • Sail
The constellation is visible in latitudes from + 54 ° to -90 °.
The best time to watch is February.

Accommodates 3 stars with planets and no Messier objects or meteor shower. The brightest star is Alpha Compass, with an apparent visual magnitude of 3.68. It is part of the Heavenly Waters group, where the Dove, Dolphin, Eridanus, Korma, Sails, Southern Fish, Small Horse and Keel are also located. view the constellation diagram Compass on the star chart.

Constellation compass


In the years 1751-1752. it was created by the French astronomer Nicolas Louis de Lacaille, when he was studying the southern sky. He named it “Boussole”, after which it was renamed in the Latin manner “Pixis Nautica” (1763). In the end, they decided to shorten and use only “Pyxis” (Compass).

It is a magnetic compass used by mariners on their travels. But you shouldn t compare it with the Compass used by the draftsmen. It is located very close to the three constellations that originally represent the Ship Argo (the ship of the Argonauts). It was Lacaille who decided to divide the large constellation into Carina, Sails and Stern. Therefore, the Compass is sometimes considered the fourth constellation and a particle of the ship. Although it never happened. Ptolemy named the stars from Alpha to Delta Compass, but they were all around the ship s mast.

In 1844, John Herschel proposed to name the constellation Mast and thus make it part of the ship, but he was not supported. After being approved by the International Astronomical Union, the Compass entered the modern 88 constellations.

Main stars

Explore the bright stars of the constellation Compass with a detailed description, photo and characteristics.

Α Compass (Alpha Compass) is a giant (B1.5III) with an apparent visual magnitude of 3.67 and a distance of 880 light years. This is the Beta Cephei variable (brightness changes due to surface ripples).

10 times the solar mass, 6 times the radius, and 10,000 times brighter. Will end its existence in a supernova explosion.

Β Compass (Beta Compass) is a double star (G7Ib-II) with a total apparent magnitude of 3.954 (second in brightness in the constellation) and a distance of 420 light years.

It is a bright giant or yellow supergiant. Exceeds the solar radius 28 times. It is accompanied by a 12.5-magnitude visual companion at a distance of 12.7 arc seconds.

Gamma Compass is an orange giant (K3III) with a visual magnitude of 4.026 and a distance of 209 light years. It is in third place in terms of brightness in the constellation.

Compass T is a binary star, represented by a sun-like star and a white dwarf. Its usual visual magnitude is 15.5, but since it is a recurring nova, it shows magnitude 6.4 during an eruption. Now only 10 new stars are known. Its eruptions were recorded in 1890, 1902, 1920, 1944, 1966 and 2011.

The two stars are close to each other, so the white dwarf takes mass, leading to periodic eruptions. Despite this, the star is gaining mass and it is believed that it will soon explode as a type 1a supernova. This will happen in the next 10 million years. Unfortunately, the forecasts are disappointing. Such an explosion will destroy the ozone layer of our planet and destroy life.

T Compass

T Compass

Kappa Compass is a double star (K4 / K5III) with a total magnitude of 4.62 and a distance of 487 light years. In 2.6 million years, it will approach the Sun by 306 light years and increase in magnitude to 3.34. The main object is the orange giant.

Theta Compass is a red giant (M0III) with a visual magnitude of 4.71 and a distance of 522 light years. It was within 241 light years of the Sun at 5.8 million years ago with an apparent magnitude of 3.12.

Zeta Compass is a multiple star. The bright object is a yellow giant (G5III), located 236 light years away.

Delta Compass is a star system with an apparent magnitude of 4.87 and a distance of 226 light years. The main component is a white subgiant (A3IV).

Celestial objects

NGC 2818 is a planetary nebula covering a radius of 3.25 light years and 10,400 light years distant from us. Formed when a dying star shattered the outer layers. The rest of the core is a white dwarf.

NGC 2818 is a rare case of a planetary nebula in the Milky Way located inside a star cluster. Captured by the Hubble Space Telescope.

NGC 2818 is a rare case of a planetary nebula in the Milky Way located inside a star cluster. Captured by the Hubble Space Telescope.

NGC 2627 is an open cluster with a visual magnitude of 8.4 and a distance of 8,000 light years. Located southwest of Zeta Compass. It contains 40 stars, whose magnitudes are 11-13.

NGC 2613 is a barred spiral galaxy with a “face” view. It is located 60 million light-years from us, and its apparent magnitude reaches 10.6. Reminiscent of the Milky Way.

NGC 2613

NGC 2613

You have the opportunity to study the constellation Compass of the Southern Hemisphere more closely if you use not only our photos, but 3D models and an online telescope. For an independent search, a map of the starry sky is suitable.

Constellations of the spring sky

MarchCancer Dog Lesser Keel Lynx Poop Compass Sails Flying Fish
AprilPump Chameleon Bowl Hydra Lion Little Lion Sextant Ursa Major
MayHounds Dogs Centaurus Hair of Veronica Raven Southern Cross Fly Virgo


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