M19
Globular Cluster in Ophiuchus
About
A globular cluster in Ophiuchus, about 28,700 light-years away and only about 6,500 light-years from the Galactic Centre. It looks unusually flattened, but dust dimming its eastern edge accounts for part of that; in infrared it looks almost round.
Imaging tips
- About 14′ across: roughly 1,730–2,890 mm on APS-C, or 2,650–4,420 mm on full frame, to span a third to half of the frame.
- Globular clusters have no emission to isolate, so broadband colour is the choice; one remote 20-inch reflector gathered 45 minutes of luminance and 2 h 15 min of RGB.
- It stays low from the north: peak altitude is about 14° from 50°N, so expect haze and poor seeing; the deep example found used a southern-hemisphere remote scope at 3 hours.
- Best in May and June.
Facts
- Size
- 14′
- Magnitude
- 6.8
- Coordinates
- RA 17h 2.6m, Dec −26° 16′
- Framing, APS-C
- 1730–2890 mm
- Framing, full frame
- 2650–4420 mm
- Best months
- May, Jun
- Peak altitude
- 14° from 50°N, 29° from 35°N