| Description | M20 was discovered by Messier (eighth so far) and recorded on June 5, 1764: "Cluster of stars, a little above the Ecliptic, between the bow of Sagittarius & the right foot of Ophiuchus..' His description is completed at the end of his entry for M21 (same date) where he comments: "The stars of both these clusters [M20 & M21] are of 8-9 magnitude, enveloped in nebulosity." <--> The Trifid Nebula is a bright spot, low on the Southern Horizon, just above the Lagoon Nebula... It is connected by a band of HII gas to the Lagoon, although it's unclear whether Messier could see this. Collectively, these make up one of the most active star forming regions in our part of the Milky Way, eclipsed only by the Orion complex. Trifid, btw, means "3-lobed" which is an obvious name when you examine the "bulb" and appear to be an illusion established by strands of dark nebulae stretched across the HII bubble. The blueish "cap" is a reflection nebula. I hadn't planned on observing this object, but it was a partly cloudy night and the southern horizon was the clearest. The Trifid was quite low, around 20° when the observation started, but far enough west to miss the tall trees on my property which are closer to the meridian. Transparency was mediocre, with a rising moon illuminating the sky. But I was able to capture this fairly quickly, with my camera set to Bin 2 and using the L-eNhance dual band filter. The bright edge at the bottom of the image is the start of the Lagoon Nebula (M8). |
