M71 Globular Cluster in Sagitta

Last night there were a few hours of clear sky so I thought I would do a bit of star gazing. Sometimes I come across more stars than you could shake a stick at. Like this picture I got of M71, a globular clusters of stars in the constellation Sagitta (yes Sagittarius). It is in the direction of a particularly rich area of the Milky Way. As you can see that provides a backdrop of so many stars you hardly tell which ones are in the cluster and which are not. If you double click on this image to see it enlarged the whole picture is stellar.

 

The M71 cluster has about 20,000 stars, is about 13,000 light years away and is estimated to be 27 light years across. Or 90 light years across - apparently it depends on which stars can be deemed to be a part of the cluster and which are apart from it.

 

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Telescope: Celestron C11-A XLT Schmidt Cassegrain OTA

Mount: SkyWatcher EQ6-R Pro

 

Controller: ZWO ASIAIR Plus 256G

Main Camera: ZWO ASI533MC Pro at -10C

Filter: ZWO UV/IR cut filter

Focuser: ZWO EAF

Guide Camera: ZWO ASI174MM Mini guidecam

Guide via: ZWO OAG

 

Stacked from:

Lights 20 at 120 seconds, gain 101, temp -10C

Darks 30 at 120 seconds, gain 101, temp -10C

Flat 30 at 430ms, gain 101, temp -10C

Dark Flat 30 at 430ms gain 101 temp -10C

 

Bortle 4 sky.

Integrated the saved frames in Astro Pixel Processor.

Processed in PixInsight

Added captions in Photoshop CS4

 

 

 

Done