The constellation of Serpens, the east segment known as Serpens Cauda (its tail) in the northern summer sky, with parts of Ophiuchus at right and Scutum at left. The Serpens-Ophiuchus Double Cluster is at left, made of NGC 6633 (right) and IC 4756 (left). The binocular cluster IC 4665 is above greenish Beta Ophiuchi (Cebalrai) at centre. Blue Rasalhague and orange Rasalgethi are at top right. To the left (east) of Cebalrai at centre is the V-shaped asterism known as Taurus Poniatowski or the “Little Bull,” a group that resembles the Hyades in Taurus. The group was named for the King of Poland, Stanislaus Poniatowski in 1777 by Marcin Poczobutt. The constellation pattern was never accepted but the asterism, now in Ophiuchus, is a fine one for binoculars. This is a stack of 4 x 1-minute exposures with the 50mm Sigma lens at f/2.8 and Canon 6D at ISO 1600, plus an additional 1 min exposure through the Kenko Softon filter to add the star glows. All tracked on the MSM SiFo Tracker from China. Taken from home July 24, 2019.
This is an impressive area of sky rich in bright and dark nebulas and open star clusters in Sagittarius and Serpens. This is closeup of the Small Sagittarius Starcloud, aka Messier 24, at bottom right, with the field extending north to include the nebulas M17, the Swan Nebula, and M16 at top right, the Eagle Nebula. Between M17 and M24 is the small star cluster M18. Patches of red and blue nebulosity at bottom right below M24 are IC 1283 and the blue reflection nebulas NGC 6589 and 6590. The prominent dark nebula at the right (west) edge of the Starcloud is Barnard 92 with its lone star embedded in it, with smaller B93 above it. At the left are the star clusters M25 (bottom) and NGC 6645, with the large dark nebula B312 above. This is a stack of 3 x 6-minute exposures with the William Optics RedCat 51mm astrograph at f/5 and the Canon EOS Ra at ISO 800 with LENR on as it was the warmest night of the summer, August 17, 2020. Aligned, stacked and mean combined in Photoshop. Autoguided with the ZWO ASIAir and ASI120MM guide camera with the RedCat on the Astro-Physics Mach1 mount. No filters employed here. Clouds thwarted more exposures.
The trio of large open clusters ideal for binoculars grouped in Ophiuchus and Serpens — with IC 4756 at left in Serpens, NGC 6633 in Ophiuchus to the right of IC 4756, and IC 4665 at right of frame above the bright star Beta Ophiuchi, or Cebalrai, in Ophiuchus. The pair of NGC 6633 and IC 4756 are also known as the S-O Double Cluster, for their home in Serpens and Ophiuchus. They are an obvious sight when scanning the west side of the summer Milky Way. Below Cebalrai is the large asterism known as Taurus Poniatowski or the “Little Bull,” a group that resembles the Hyades in Taurus. The group was named for the King of Poland, Stanislaus Poniatowski in 1777 by Marcin Poczobutt. The constellation pattern was never accepted but the asterism, now in Ophiuchus, is a fine one for binoculars. This is a stack of 9 x 2-minute exposures at f/2.8 with the 85mm Rokinon lens and Canon 6D MkII at ISO 800, plus a single exposure with the Kenko Softon filter blended in to add the star glows.
