Shield (constellation)
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Constellation shield |
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| Latin name | Scutum |
| Latin genitive | Scuti |
| Abbreviation | Sct |
| Right ascension | 18 h 21 m 36 s to 18 h 59 m 10 s |
| declination | −15 ° 56 ′ 37 ″ to −3 ° 50 ′ 01 ″ |
| surface | 109.114 deg² rank 84 |
| Completely visible | 74.6 ° N to 90 ° S |
| Observation time for Central Europe | summer |
| Number of stars brighter than 3 mag | 0 |
| Brightest star (size) | α Scuti (3.85) |
| Meteor streams | |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
 The constellation shield as it can be seen with the naked eye |
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The shield ( Sobieskischer Schild , Latin Scutum ) is a constellation near the celestial equator .
description
The shield is a small, inconspicuous constellation south of the eagle (Aquila). It lies in the star-rich Milky Way , so there are several foggy objects in the shield, such as two open star clusters and a globular cluster .
history
The constellation was first listed in 1690 in the work Firmamentum Sobiescianum by Johannes Hevelius and is dedicated to the Polish King Jan III. Dedicated to Sobieski (1629–1696), who liberated the city of Vienna from the Turkish besiegers in 1683 at the Battle of Kahlenberg . It symbolizes the shield that the king wore in battle and so the original name was Scutum Sobiescianum ("Shield of Sobieski").
Of several proposed constellations that referred to people of modern times, apart from the shield, only the telescope , with which Lacaille honored the inventors of the telescope, has found its way into the list of 88 modernly recognized constellations.
Celestial objects
Stars
| B. | Designations | size | Distance / Lj | Spectral class |
|---|---|---|---|---|
| α | 3.85 m | 174 | K2 III | |
| β | 4.22 m | 690 | G5 II. | |
| ζ | 4.68 m | 191 | K0 III | |
| γ | 4.70 m | 292 | A1 IV / V | |
| δ | 4.60 to 4.79 m | approx. 200 | F2 IIIp | |
| η | 4.83 m | 207 | K1 III | |
| ε | 4.88 m | 523 | G8 II | |
| Struve 2325 | 5.72 m | |||
| R. | 4.4 to 8.2 m | 2500 | G7 Ib |
The brightest star in the shield is α Scuti, a 174 light-years away star of the spectral class K2 with 20 times the diameter and 130 times the luminosity of our sun .
Multiple stars
| system | Sizes | distance |
|---|---|---|
| δ | 4.72v / 9.2 / 12.2 | |
| Struve 2325 | 5.8 / 9.1 |
δ Scuti is a multiple star system about 200 light years away , consisting of three stars.
Variable stars
| star | size | period | Type |
|---|---|---|---|
| δ | 4.60 to 4.79 m | 4.67 hours | Short-periodically variable |
| R. | 4.4 to 8.2 m | 140 to 146 days | RV Tauri star |
The main star of the system δ Scuti is the namesake of a group of short -period pulsation - variable stars , the Delta Scuti stars . Its brightness changes over a period of 4 hours and 40 minutes from 4.60 to 4.79 m . The star has about twice the mass and 15 times the luminosity of our sun. Spectroscopic studies show that its shell is rich in heavy elements.
R Scuti is a semi-regular pulsation-variable star of the RV-Tauri type, 2500 light-years away . In these stars, shallow and deep brightness minima alternate.
Messier and NGC objects
| Messier (M) | NGC | other | size | Type | Surname |
|---|---|---|---|---|---|
| 11 | 6705 | 5.8 m | Open star cluster | Wild Duck Nebula | |
| 26th | 6694 | 8.0 m | Open star cluster | ||
| 6712 | 8.5 m | Globular clusters |
In the shield there are two open star clusters that the French astronomer and comet hunter Charles Messier added to his catalog of foggy objects ( Messier catalog ).
The M 11 , 5,700 light years away, is one of the most prominent open star clusters in the night sky. It can already be seen in prism binoculars , and over 400 stars can be seen in a medium-sized telescope . Since its shape is reminiscent of a flying duck, it is also called "Wild Duck Nebula" (wild duck nebula).
M 26 is an open star cluster 5,000 light years away. It is less impressive than M 11. 15 to 20 stars are visible in the telescope.
NGC 6712 is a globular cluster 20,000 light years away . To resolve it into single stars, however, you need a larger telescope.
