|Designation: Caldwell 87, NGC 1261, in constellation of Horologium.|
|Visual magnitude: +8.3|
|Apparent size: 6.8 arc-minutes.|
|Diameter: 105 light years.|
|Distance: 53,000 light years.|
|Exposure: 25 frames @ 107 sec = 44 minutes|
There are about one hundred and fifty globular clusters in orbit around the Milky Way galactic core. Their habitat is the halo outside the spiral disc. They all share a similar resemblance – a spherical collection of stars, tightly bound by their common centre of gravity, with an increasingly dense stellar population towards their centres.
Caldwell 87 is not a particularly bright globular cluster, nor is it especially large. It lies in the southern sky at a considerable distance of 53,000 light years and so is not one of the most conspicuous.
However, having started out on a journey which includes a target of photographing as many Caldwell and Messier objects as I can, it becomes one of those which I can add to the list.
The bright nearby star is HD 20224, magnitude 9.1.
I managed just three imaging sessions during this lunar cycle, all from home. I can’t complain about that but after nearly seven weeks of home isolation already, spending an evening under the stars seems to be a rare treat. Even a night under a moonlit sky tonight or tomorrow would be looking attractive if it were not for the gusty wind.
Annotation from Astrometry.net
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor.|
|840 mm focal length @ f/7 with field flattener.|
|Baader L-Booster UHC-S light pollution filter 2458276.|
|SkyWatcher EQ6-R Pro mount.|
|Camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx)|
|ZWO ASI120 guide camera, using PHD2 software.|