| Object: M28 (NGC 6626) | Date: 2018 August 1 |
| Type: Globular cluster | |
| Constellation: Sagittarius | Time & altitude: 21.25 UT 14º |
| Catalogue data: | Seeing (5 high): 2/5 |
| R.A: 18h 25m | Transparency (5 high): 2/5 |
| Dec: -24º 52 | Telescope: 0.5m f4.1 Dob. |
| Magnitude 6.9 | Eyepiece 8mm Ethos x260 |
| Size (mins) 11 | Filters: None |
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Notes: Observed at culmination but low altitude even so. Many aircraft contrails are making the sky milky and there’s a lot of turbulence after another sunny day. Checking my sketch with Megastar, the faintest star I have recorded is 12th mag. so that’s about 3 magnitudes of extinction. The perceived diameter is about 2 arc minutes, much smaller than the catalogue value. The central 1 arc minute of the cluster is evenly illuminated, there is no peak to a bright nucleus. I’ve only got resolution into stars outside this central area. There is a bar of stars running NE-SW across the centre of the cluster. |
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