|Object name:||Constellation:||Coordinates:||Apparent size:||Visual brightness:|
|Messier 11 (= NGC 6705)||Scutum||18h51m / -06°16'||14'||5.8 mag|
The open star cluster Messier 11 (NGC 6705, "Wild Duck Cluster") in the constellation Scutum (Shield). The Wild Duck Cluster is one of the richest and most compact of the known open clusters, containing about 2,900 stars. Its age has been estimated to about 250 million years. Its name derives from the brighter stars - all luminous giants - forming a triangle which could resemble a flying flock of ducks (or, from other angles, one swimming duck). Messier 11 is 6,000 light-years from Earth and was discovered by German astronomer Gottfried Kirch in 1681 (source: Wikipedia).
Twenty-four 3-minute exposures (72 minutes total exposure) at gain 100, taken on July 09 / 10, 2021, were added for this shot with Astro Pixel Processor (APP) software and the final image processing was done in Photoshop. Darks, flats, and darkflats were used.
Equipment: Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system.