Capricorn (constellation)
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Capricorn constellation |
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| Latin name | Capricornus |
| Latin genitive | Capricorni |
| Abbreviation | Cap |
| Right ascension | 20 h 06 m 46 s to 21 h 59 m 05 s |
| declination | −27 ° 38 ′ 31 ″ to −8 ° 24 ′ 16 ″ |
| surface | 413,947 deg² rank 40 |
| Completely visible | 62.5 ° N to 90 ° S |
| Observation time for Central Europe | Summer autumn |
| Number of stars brighter than 3 mag | 1 |
| Brightest star (size) | Deneb Algedi (2.73) |
| Meteor streams | |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
The Capricorn ( Latin Capricornus , astronomical sign ♑) is a constellation of the ecliptic .
description
The Capricorn (also goat fish, therefore often depicted with a fish tail (see picture)) is an inconspicuous constellation between Aquarius and Sagittarius . Only two of its stars reach the 3rd magnitude . The brightest star in the constellation is called Deneb Algedi .
history
Capricorn is one of the 48 constellations of ancient Greek astronomy that were already described by Ptolemy .
The constellation is one of the signs of the zodiac because the ecliptic runs through it. The sun stays in Capricorn from January 20th to February 16th of each year.
In ancient times, the sun passed the lowest point of its orbit in Capricorn and marked the winter solstice . The latitude of 23 ° 26 'south is still called the Tropic of Capricorn today, as the sun is at its zenith at the winter solstice at this latitude . In fact, the lowest point of the sun's orbit has shifted into the constellation Sagittarius due to the precession movement of the earth's axis .
On September 23, 1846, Johann Gottfried Galle discovered the eighth planet Neptune near the star δ Capricorni ( Deneb Algedi ) in Capricorn.
mythology
Capricorn is probably one of the oldest constellations. The Babylonians called it "goat fish". A profane explanation for this is that the residents of the Red Sea and the Arabian Sea used the constellation to mark the time when schools of the goat fish ( Parupeneus forsskali ) were to be caught.
Only in Roman times was the constellation renamed Capricorn. Nevertheless, it is still represented today as a being with the upper body of a goat and the lower body of a fish.
The Greek mythology after jumping the bockbeinige god Pan on the run from the monster Typhon made, the hunt for the gods into the sea. Pan wanted to take on the shape of a fish, but he only half succeeded. Typhon then attacked the god Zeus and tore out the tendons on his arms and legs. Pan and Hermes reinstalled Zeus' tendons. The restored Zeus overpowered Typhon and gave Pan in his form as a goat fish in thanks to heaven.
Meteor streams
The radiant of the Alpha Capricornid meteor shower is in Capricorn. The meteor shower can be observed from July 15th to September 11th, with the maximum of 6-14 meteors per hour occurring between August 1st and 2nd.
Celestial objects
Stars
| B. | F. | Names or other designations | like | Lj | Spectral class |
|---|---|---|---|---|---|
| δ | 49 | Delta Capricorni , Deneb Algedi, Scheddi | 2.81-3.05 | 39 | kA5hF0mF2 III |
| β 1 | 9 | Beta 1 Capricorni , Dabih, Giedi, Sadalzabih | 3.21 | 330 | K0 II + A5: n |
| α 2 | 6th | Alpha 2 Capricorni , Algedi, Secunda Giedi | 3.74 | 106 | G8.5 III-IV |
| γ | 40 | Gamma Capricorni , Nashira | 3.77 | 157 | kF0hF1mF2 V |
| ζ | 34 | Zeta Capricorni , Marakk | 3.92 | 385 | G8 III + DA2 |
| θ | 23 | Theta Capricorni , Dorsum | 4.08 | 162 | A1 V |
| ω | 18th | Omega Capricorni , Baten Algiedi | 4.22 | 840 | K4 III |
| ψ | 16 | Psi Capricorni , Pazan | 4.23 | 48 | F5 V |
| α 1 | 5 | Alpha 1 Capricorni , Prima Giedi | 4.41 | 570 | G3 Ib |
| ι | 32 | Iota Capricorni | 4.44 | 197 | G8 III |
| ε | 39 | Epsilon Capricorni , Kastra | 4.45 | 1055 | B3 V |
| 24 | 4.61 | 455 | K5 / M0 III | ||
| b | 36 | 4.66 | 170 | K0 III | |
| ν | 8th | Ny Capricorni , Alshat | 4.75 | 253 | B9 IV |
| ρ | 11 | 4.85 | 99 | F2 V | |
| κ | 43 | 4.88 | 294 | G8 III | |
| η | 22nd | Eta Capricorni , Armus | 4.90 | 161 | A5 V + F2 V |
| π | 10 | Pi Capricorni , Okul | 5.07 | 545 | B3.5V |
| μ | 51 | My Capricorni | 5.17 | 87 | F2 V |
| τ | 14th | 5.20 | 1140 | B7 III | |
| υ | 15th | 5.23 | 580 | M1 III | |
| c | 46 | 5.26 | 790 | G8 II-III | |
| χ | 25th | 5.32 | 180 | A0 V | |
| φ | 28 | 5.33 | 640 | K0 II / III | |
| σ | 7th | 5.44 | 1120 | K2 III | |
| λ | 48 | 5.58 | 282 | A0 V | |
| ξ | 2 | 5.95 | 90 | F7 V |
θ Capricorni ( dorsum , Latin for "back"), a white main sequence star , is 162 light years away. The star rotates unusually fast.
μ Capricorni, a white-yellow main sequence star 87 light-years away, shows a fast proper motion in the sky of 312 milli-arcseconds / year. Taking into account its radial motion, the star moves at a speed of 62 km / s relative to the sun .
ν Capricorni ( Alshat , Arabic for "the sheep") is a blue-white subgiant about 253 light years away.
ψ Capricorni ( Pazan , Persian "Capricorn") is a white and yellow main sequence star 48 light years away. It bears some resemblance to the sun.
Multiple stars
| system | like | distance |
|---|---|---|
| δ | 3.0 / 12.7 | 119 ″ |
| β | 3.4 / 6.2 | 205 ″ |
| α 2 | 3.8 / 11.2 | 6.6 ' |
| ζ | 3.9 / 12.5 | 21 ″ |
| ω | 4.2 | |
| α 1 | 4.6 / 9.6 | 44 ″ |
| 24 | 4.6 / 11.7 | 26 ″ |
| ε | 4.7 / 9.5 | 68 ″ |
| ν | 4.8 / 11.8 | 54 ″ |
| ρ | 5.0 / 10.0 | 0.5 ″ |
| η | 5.2 / 6.5 | 0.3 ″ |
| π | 5.2 / 8.8 | 3.2 ″ |
| τ | 5.6 / 6.9 | 0.3 ″ |
| χ | 5.3 / 11.0 | 67 ″ |
| σ | 5.5 / 9.0 | 56 ″ |
| ξ | 5.9 / 12.1 | 72 ″ |
The Capricorn contains some binary star systems that can be resolved into single stars in binoculars or a small telescope .
The second brightest star in Capricorn, β Capricorni ( Dabih , Arabic “slaughter”), is a multiple star system about 330 light years away. Due to the large angular distance, the two main components β 1 and β 2 ( Dabih Maior and Dabih Minor ) can be separated using binoculars. Each of the two main components is itself multiple.
α Capricorni ( Algedi , Arabic “billy goat”) appears as a double star to the naked eye (distance 6.6 '). The stars α 1 and α 2 are not physically bound to each other, but only stand in one direction when viewed from the earth. It is therefore an "optical" double star. Both stars are actually "real" multiple stars, but their companions only become visible in the telescope.
The brighter α 2 is 106 light years away and is a system of four components with a yellow giant star as the main star. The system α 1 is much further away with 570 light years and a system of at least five components with a yellow supergiant as the main star.
ζ Capricorni ( Marakk , Arabic “soft belly”) is a yellow giant star 385 light years away, ω Capricorni ( Baten Algiedi , Arabic “belly of the billy goat”) is a red giant star 840 light years away. Their spectrum shows peculiarities according to which they were classified as barium stars . They are typically orbited by white dwarfs .
η Capricorni ( armus , Latin for "upper arm, shoulder") is a close double star around 160 light years away, the two stars orbiting each other in 28 years. When it was covered by the moon, it was observed for the first time in 1950 that this occurred in two stages.
π Capricorni ( Okul , Latin for "eye") is a multiple star 545 light years away. The main star is a blue-white main sequence star.
Variable stars
| star | like | period | Type |
|---|---|---|---|
| δ | 2.81-3.05 | 1.02277 d | β Per (Algol) |
| γ | 3.77 | α 2 CnV | |
| ι | 4.44 | BY Dra | |
| ε | 4.45 | γ Cas |
δ Capricorni is a multiple system, the main star of which is an eclipsing star of the Algol type , its brightness decreases by 0.2 mag every 24.5 hours. This decrease in brightness is caused by a weaker companion star, which, when viewed from Earth, moves in front of the main star and darkens it every 24.5 hours. δ Cap is the brightest star in Capricorn. The Arabic name Deneb Algedi means "tail of the billy goat".
γ Capricorni ( Nashira , Arabic "spreading (he lucky star)") is a rotationally variable star of the Alpha 2 -Canum-Venaticorum type, it shows magnetic field fluctuations as well as very small brightness fluctuations.
ι Capricorni is a yellow giant star about 200 light years away. It is a rotationally variable BY Draconis- type star .
ε Capricorni ( Kastra , Latin for "camp, barracks") is a blue-white main sequence star about 1055 light years away. It is an irregularly eruptive variable of the Gamma-Cassiopeiae type .
Messier and NGC objects
| Messier (M) | NGC | Surname | like | Type |
|---|---|---|---|---|
| 30th | 7099 | 7.7 | Globular clusters |
In Capricorn there are only a few conspicuous galactic nebulae, star clusters or galaxies, only one globular star cluster was included in his catalog of foggy objects ( Messier catalog ) by the French astronomer and comet hunter Charles Messier .
M 30 is a globular cluster with a distance of about 26,000 light years. Even in binoculars it can be seen as a misty spot. In order to resolve it into single stars at the edge, however, you need a larger telescope.
Special constellations
On July 27, 2018, both the Moon and Mars were in opposition in the constellation Capricorn as the longest lunar eclipse of the 21st century occurred.
Web links
- Cross reference for 49 stars in the constellation.
- Astronomie.de: The Capricorn
- Capricorn constellation A photographic journey through the signs of the zodiac