- Snake ( tail)
The shield ( shield Sobieskischer, latin scutum ) is a constellation near the celestial equator.
The shield is a small, inconspicuous constellation south of the Eagle (Aquila ). It is in the starry Milky Way, so you can find the sign more nebulous objects, such as two open clusters and globular clusters.
The constellation was first listed in 1690 in the work Firmamentum Sobiescianum Johannes Hevelius and the Polish king Jan III. Sobieski (1629-1696) dedicated to the at the Battle of Kahlenberg Vienna liberated in 1683 by the Turkish occupiers. It symbolizes the shield, which the king wore in battle, and that was the original name Scutum Sobiescii ( " Shield of Sobieski "). It is not the only constellation that refers to a person of the modern age, as Lacaille has paid tribute to the inventor of the telescope in the constellation Telescopium.
The brightest star in the shield is α Scuti, a 174 light-years distant star of spectral type K2 with 20 times the diameter and the 130fachen luminosity of our sun.
δ Scuti is about 200 light years distant multiple star system consisting of three stars.
The main star of the system δ Scuti is the namesake of a group of short-period pulsating variables stars, the Delta Scuti stars. Its brightness varies over 4 hours and 40 minutes between 4.60 to 4.79 m. The star has about twice the mass and the luminosity of our sun 15 times. Spectroscopic studies show that its envelope is rich in heavy elements.
R Scuti is a 2500 light years distant semi- regularly pulsationsveränderlicher RV Tauri -type star. In these stars is shallow and deep Helligkeitsminima alternate.
Messier and NGC objects
In the shield are two open clusters are the French astronomer and comet hunter Charles Messier in his catalog of nebulous objects ( Messier catalog) recorded.
The 5,700 light-years away, M11 is one of the most prominent open clusters in the night sky. It is already apparent in the prism binoculars in a middle telescope are about 400 stars visible. Since its shape is reminiscent of a flying duck, it is also called "Wild Duck Nebula " ( wild ducks fog).
M 26 is an open cluster in 5,000 light -years away. He is less impressive than M 11 In a telescope are 15 to 20 stars visible.
NGC 6712 is a 20,000 light-years distant globular clusters. To resolve it into individual stars but you need a larger telescope.