Swordfish (constellation)
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Swordfish constellation |
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|---|---|
  |
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| Latin name | Dorado |
| Latin genitive | Doradus |
| Abbreviation | Dor |
| Right ascension | 03 h 53 m 17 s to 06 h 35 m 45 s |
| declination | −70 ° 06 ′ 15 ″ to −48 ° 40 ′ 12 ″ |
| surface | 179,173 deg² rank 72 |
| Completely visible | 19.9 ° N to 90 ° S |
| Observation time for Central Europe | Not visible |
| Number of stars brighter than 3 mag | 0 |
| Brightest star (size) | Doradus (3.27) |
| Meteor streams |
no |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
The swordfish ( Latin Xiphias and Dorado ) is a small constellation in the southern sky. In it lies the southern pole of the ecliptic and the large Magellanic Cloud .
description
The swordfish is an inconspicuous constellation consisting of several stars that are arranged in a line . It's easy to find because it's southwest of Canopus , the second brightest star in the sky.
The greater part of the conspicuous Large Magellanic Cloud , a companion of our galaxy, is located in the swordfish .
Because of its southern location, it can not be seen from Europe .
Due to the precession, the south celestial pole moves once around the south pole of the ecliptic , which lies in this constellation, in around 25,800 years . The south celestial pole thus always remains close to this constellation because it has orbited it over the course of thousands of years. Therefore, in contrast to many other southern constellations, such as. B. Southern Cross, Toucan or Peacock will not rise in Europe even in millennia.
history
The swordfish is one of the twelve constellations introduced by Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman at the end of the 16th century . Originally the constellation was called "Goldfish" and was depicted on a Dutch celestial globe that has since disappeared . Johann Bayer took it in his 1603 published sky atlas Uranometria .
Celestial objects
Stars
| B. | F. | Names or other designations | size | Lj | Spectral class |
|---|---|---|---|---|---|
| α | 3.30 m | 200 | A0 III | ||
| β | 3.5 to 4.1 m | 8000 | F8 Ia | ||
| γ | 4.26 m | 70 | F3 V | ||
| δ | 4.34 m | ||||
| 36 | 4.65 m | ||||
| ζ | 4.71 m | ||||
| θ | 4.81 m | ||||
| η 2 | 5.01 m | ||||
| ν | 5.06 m | ||||
| ε | 5.10 m | ||||
| λ | 5.14 m | ||||
| κ | 5.28 m | ||||
| 28 | 5.34 m | ||||
| π 2 | 5.37 m | ||||
| π 1 | 5.56 m | ||||
| η 1 | 5.72 m | ||||
| AB Doradus | 6.93 m | 48.74 | K2 Vk + M5 V + M5.5 V + M8 |
α Doradus , the brightest star in the swordfish, is 200 light years away. It belongs to the spectral class A0 III.
Variable stars
| star | size | period | Type |
|---|---|---|---|
| β | 3.5 m - 4.1 m | 9,842 days | Cepheid |
| γ | 4.25 m | two sinusoidal changes at 17.6 and 18.2 hours | Gamma Doradus (prototype) |
β Doradus is a variable star of the Cepheid type . Its brightness changes with a period of 9.842 days. Although it is 8,000 light years away, it can be clearly seen with the naked eye. This makes it one of the most luminous stars in the sky.
γ Doradus (Gamma Doradus, HR 1338) is the prototype for variable stars, the brightness of which fluctuates due to non-radial pulsations of the surface and which are referred to as Gamma Doradus stars . In addition, it shows some inexplicable fluctuations in its brightness.
NGC and other objects
| NGC | other | size | Type | Surname |
|---|---|---|---|---|
| LMC | 5 m | Galaxy | Large Magellanic Cloud | |
| 1549 | 9.8 m | Galaxy | ||
| 1553 | 9.4 m | Galaxy | ||
| 1566 | 9.7 m | Galaxy | ||
| 1672 | 9.7 m | Galaxy | ||
| 1755 | Globular clusters | |||
| 1763 | Emission nebula | |||
| 1820 | Open star cluster | |||
| 1850 | Globular clusters | |||
| 1854 | Globular clusters | |||
| 1866 | 9.7 m | Globular clusters | ||
| 1869 | Open star cluster | |||
| 1901 | Open star cluster | |||
| 1910 | Open star cluster | |||
| 1936 | Emission nebula | |||
| 1978 | Open star cluster | |||
| 2002 | Open star cluster | |||
| 2027 | Open star cluster | |||
| 2032 | Emission nebula | |||
| 2070 | 5.4 m | Emission nebula | Tarantula mist | |
| 2157 | Open star cluster | |||
| 2164 | Globular clusters | |||
| N44 | Emission nebula | |||
| N159 | H-II area |
Large Magellanic Cloud
The Large Magellanic Cloud (English: Large Magellanic Cloud , LMC) is the brightest and largest nebulous object in the night sky. It has an extension of 5 ° by 6 °. It is a smaller companion galaxy to our Milky Way galaxy around 160,000 light years away. It contains several star clusters and nebulae that can already be observed with small telescopes , such as the well-known tarantula nebula . The Magellanic Cloud is a fantastic sight in prism binoculars or telescopes. In 1987 a supernova flared up there , the closest to earth in 383 years.
The Tarantula Nebula (NGC 2070) is an emission nebula in the Large Magellanic Cloud and thus also 160,000 light years away. It has 5,000 times the luminosity of the Orion Nebula and is the largest known object of its kind in the universe. In the smaller telescope it can be seen as a misty spot. Structures that are reminiscent of a spider and gave the nebula its name become visible in larger instruments. It contains large star clusters such as R136 and Hodge 301 , which illuminate the gas nebula from within. R136a1 in the cluster R136 is the brightest and most massive of all stars known to be stable.
In the constellation Swordfish there are also the much more distant galaxies NGC 1549 , NGC 1553 , NGC 1566 and NGC 1672 .
See also
Web links
Individual evidence
- ^ Joannis Keill introductiones ad veram physicam et veram astronomiam , MDCCXXV (1725), p.257
- ^ Davidis Gregorii astronomiae physicae & geometricae elementa. Secunda Editio revisa & correcta , Genevae (in the nominative Geneva, German Geneva), M. DCC. XXVI. (1726), p.239
- ↑ Elementa physicae conscripta in usus academicos a Petro van Musschenbroek , Bassani, MDCCLXXXI (1781), p.304