Messier 10 (Ophiuchus)
Fig. 1 - High population of blue stragglers (stars that appear younger than their neighbors): Messier 10 in Ophiuchus, photographed with a 16-inch f/4.5 Dob on an equatorial platform.
| Object name: | Constellation: | Coordinates: | Apparent size: | Visual brightness: |
|---|---|---|---|---|
| Messier 10 (NGC 6254) | Ophiuchus | 16h57m / -04°06' | 20' | 6.6 mag |
The globular cluster Messier 10 (NGC 6254) in the constellation Ophiuchus. Messier 10 is the second brightest globular cluster in Ophiuchus and is estimated to be 14,300 light-years away from Earth. Its spatial diameter is approximately 83 light-years. Messier 10 was discovered by French astronomer Charles Messier in 1764 (source: Wikipedia).
Exposure time: 1h 10min (70x1min) at gain 100 and -10°C, taken on June 25 / 26, 2023, were added for this shot with the Astro Pixel Processor (APP) software and the final image processing was done in Photoshop. Darks, flats, bias and dark flats were used.
Equipment: Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system.
Field of view comparison: image of the moon with the same equipment.
Fig. 2 - Search chart for Messier 10. Copyright 2025 'The Mag-7 Star Atlas Project', www.siaris.net.

