Circle (constellation)
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Constellation circle |
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|---|---|
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| Latin name | Circinus |
| Latin genitive | Circini |
| Abbreviation | Cir |
| Right ascension | 13 h 38 m 43 s to 15 h 30 m 22 s |
| declination | −70 ° 37 ′ 28 ″ to −55 ° 26 ′ 11 ″ |
| surface | 93.353 deg² rank 85 |
| Completely visible | 19.6 ° N to 90 ° S |
| Observation time for Central Europe | Not observable |
| Number of stars brighter than 3 mag | 0 |
| Brightest star (size) | Alpha Circini (3.19) |
| Meteor streams |
no |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
The circle (in the first name French compas - Latin / technical language Circinus ) is a constellation of the southern sky .
description
The circle is an inconspicuous constellation consisting of a group of stars, only one of which reaches the 3rd magnitude .
The bright ribbon of the Milky Way runs through the constellation . It cannot be observed from Europe.
history
The "circle" is one of the constellations introduced by the French astronomer Nicolas Louis de Lacaille in the 18th century .
Celestial objects
Stars
| star | Surname | size | Distance ( Lj ) | Spectral class |
|---|---|---|---|---|
| α | 3.19 m | 50 | F0 | |
| β | 4.07 m | 80 | A3 V | |
| γ | 4.08 m | 500 | A5 V | |
| ε | 4.85 m | |||
| δ | 5.04 m | 2500 | O9 + B1 | |
| θ | 5.08 m | |||
| η | 5.16 m | |||
| ζ | 6.09 m |
β Circini is a spectral class A3 star 80 light years away .
Double stars
| system | Sizes | distance |
|---|---|---|
| α | 3.4 m / 8.6 m | 16 " |
| δ | 5.1 m / 5.7 m | 243 " |
α Circini, the brightest star in the circle, is a binary star system . The system can be broken down into single stars with a smaller telescope .
δ Circini is an extremely bright binary star system 2500 light years away. It consists of two equally bright stars of the spectral classes O9 and B1. The system has a long distance of 243 arc seconds from the earth and can already be recognized as a double star in prism binoculars .
NGC objects
| NGC | other | size | Type | Surname |
|---|---|---|---|---|
| 5315 | 9.8 m | Planetary nebula | ||
| 5823 | 7.9 m | Open star cluster |
In the circle you can find the open star cluster NGC 5823 and the Circinus Galaxy (ESO 97-G13).
See also
Web links
Individual evidence
- ↑ The first description of the observation is published in: Sur les étoiles nébuleuses du ciel Austral , in: Memoires Academie Royale des Sciences 1755, 194-199, here 198 (No. III.9), digital copies at Google Books : [1] , [ 2] , [3] , [4] , [5] , [6] ; engl. Transl. , Additional overview ; Reviews of the observations followed, among other things. a. von Dunlop 1828, Auwer 1862 a. on cf. the reviews: [7] , [8] . Description of the single stars assigned to the constellation of Lacaille also in: Lacaille: A catalog of 9766 stars in the southern hemisphere , pp. 147.151-153 (No. 5846, 6012, 6059, 6093) ( digitized from Google Books). The introduction of the constellations then in: l'Abbé De La Caille: Table des ascensions droites et des déclinaisons apparentes des Étoiles australes renfermées dans le tropique du Capricorne, observées au cap de Bonne-espérance, dans l'intervalle du 6 Août 1751, au 18 Juillet 1752 , in: Mémoires Académie Royale des Sciences pour 1752, Paris 1756, 539-592, there 589 and in the star map ( Planisphère contenant les Constellations Célestes ) after p. 590, digitized by the BNF Paris. While the French names are used here, Lacaille uses Latinized names in the second edition: NL de Lacaille: Coelum australe stelliferum , Paris 1763, digitized at ETH Zurich and on Google Books , excerpt from the illustration at the BNF. The star map was adopted (with the French star names) in the widespread star atlas by Jean Nicolas Fortin ( Atlas Céleste , Paris 1776, digitized at Google Books, excerpt ; excerpts from the Paris 1795 edition: [9] , [10] ) and also used by Denis Diderot / Jean-Baptiste le Rond d'Alembert : Recueil de Planches de l'Encyclopédie par ordre de matieres , t. 7 p. 3, Paris - Liège 1789.