Messier 18


Click image for larger version.

The above sketch is an update to the original to clean it up, scale down fainter stars, and update formatting. The original is shown below.


Observation Notes:

This was a small condensation of stars. In my 32 mm eyepiece, it could fit in the same view with M17. I plotted 10 stars in the main body, but that could be 13 if you count a little further out.

Object Information:

M24 is a loose, poorly populated cluster with an agreed Trumpler type of II3pn. It lies about 4,900 light years away and is about 17 light years in diameter. Its hottest stars are B3 stars, indicating a young cluster that is about 32 million years old.

M24 was discovered by Charles Messier in 1764.

Subject M18 (NGC 6613)
Classification Open Cluster (Type d)
Position* Sagittarius [RA: 18:19:54 / Dec: -17:08:00]
Size* 9.0′
Brightness* 7.5
Date/Time October 22, 2005 – 8:00 PM
(October 23, 2005 – 03:00 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 25 mm (48X)
Conditions Clear, calm
Seeing 3/10 Pickering
Transparency Mag 4.5 NELM (based on 36-Capricornus)
Sources SEDS

*Based on published data.

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