Messier 71

Observation Notes:

Through the 25 mm eyepiece, this globular cluster was dim and small, but still remarkably grainy. It was also elongated. In the 10 mm eyepiece a number of stars showed at the edges and a few across the face. The shape was irregular, and seemed to make a soft arrowhead pointing WSW. An asterism of 4 stars across the surface points WSW too and leads to another line of 3 stars outside, pointing in the same direction. Not sure, but it looks like there is a detached clump of stars to the north with 3 brighter stars involved.


There has been a lot of confusion as to whether M71 should be considered a loose globular, or a dense open cluster. Not just because it is pretty loose for a globular, but also because it has a high metal content (only M69 has more), and it is fairly small at 27 light years across. Currently, it is considered to be a globular. It is 13,000 light years away, and is approaching at roughly 23 km/sec. M71 was first seen by De Chéseaux in 1746, and then catalogued by Charles Messier in 1780, and then first resolved into stars by William Herschel in 1783.

Subject M71/NGC 6838
Classification Globular Cluster
Position Sagitta [RA: 19:53.8 / Dec: +18:47]*
Size* 7.2′
Brightness* 8.2
Date/Time 10/4/04 – 9:30 PM
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 25 mm (48X); 10 mm (120X)
Seeing 4/10
Transparency Mag 5

* Based on published data.