M 20 (OC+N)

Open Cluster + Nebula in Sagittarius
R.A.Dec.SizeMag SBCnt.StTypeDistanceChart
18h 02m 42.8s-22° 58′ 19.3″20.0′8.514.7EN+OCL; 3, 3, 3OC+N----
M 20 DSS plate
Source: POSS-2 UK Schmidt Red (STScI) | Field: 30′ × 30′

Background

M20 is the Trifid Nebula — a striking star-forming region  5,200 light-years away in Sagittarius, combining a bright pink emission nebula, a blue reflection component and three prominent dark dust lanes that divide the bright region into three lobes (giving the name).

My Observing Notes

25-cm (Meade 10-inch LX200, The Coffee Grinder): Although fainter than the nearby M8, gives lovely views — the bright mass of nebulosity bisected by the dark veins (the namesake) is clearly prominent.(Saturday, June 2025)

25-cm (Meade 10-inch LX200, The Coffee Grinder): Revisited with the 35 mm Panoptic. The dark veins bisecting the nebulosity are even more striking with the wider field.(Saturday, August 2025)

44-cm (Club 17.5-inch f/5): Returned to the Lagoon area through the Club's 17.5-inch with a low power eyepiece — the wide-field view is spectacular.(Saturday, September 2025)

References

Charts

M 20 ultra-wide chart
Ultra-wide view (~25° field)
M 20 wide-field chart
Wide-field view with Telrad rings (4°, 2°, 0.5°)
M 20 finderscope view
Finderscope view (9×50 RACI, ~4.4° TFOV)
M 20 eyepiece view
Eyepiece view — 35 mm Panoptic on 12-inch f/5 (1.6° TFOV)