Brocchi's Cluster, aka The Coathanger Asterism |
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| I made an exception from my "shoot open
clusters and asterisms during a dominant Moon phase" rule when I
shot this target. This object was shot during a few nights of a
favorable Moon phase before my main targets for the nights were
too low for me to shoot. This is Brocchi's Cluster (aka Collinder 399, Cr 399 or Al Sufi's Cluster) in Vulpecula, and is identified as an asterism of 10 stars. Six of the stars appear in a row, across almost 1.5 degrees of the night sky. The cluster is in the constellation Vulpecula, near the border with Sagitta. Its distinctive shape has given it the nickname of the Coathanger. None these ten stars are believed to be gravitationally bound to each other, thus they are not classified as a star cluster (Source: Wikipedia). This object is easily found with binoculars even from a light-polluted site, and I have more than once enjoyed viewing this object (and will also confess that I may have forgotten how to find it), as it does look like the object it is nicknamed after. And as visible, the entire asterism just fits in the field of view of our remote setup. This particular image is presented South Up so the Coathanger appearance stands out. Even with the short total exposure time, some dark nebulae are visible in the final image, along with an open cluster (NGC 6802) and even a small Sharpless object (SH2-83)! Link to Astrobin version. |
| Constellation: Vulpecula |
| When Visible: July - November |
| Distance: 230 - 1100 light-years for individual stars |
| Date: Five nights in August 2026 |
| Location: Starfront Observatories, Rockwood, TX |
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Exposure Details: R = 25 x 1 minutes G = 25 x 1 minutes B = 25 x 1 minutes |
| Equipment Used: Takahashi FSQ-106N on a ZWO AM5N mount. ZWO ASI-2600MM Pro camera with 7 x 50mm filter wheel and Antlia Pro filters. Externally guided with a ZWO ASI224MC camera on a William Optics UniGuide 50 guide scope. |
| Acquisition Software : Nighttime Imaging 'N' Astronomy, PHD2 |
| Processing Software: MaximDL, PixInsight, Photoshop CS5, IrFanView |