Messier 70

Observation Notes:

This is one of 3 globular clusters I observed at the base of the Sagittaruis teapot on 10/3/04. (The others were M69 and M54. M70 appeared as a small globular cluster with a soft distribution of luminosity, with a distinct but soft core. The 120X view seemed to show one resolved star dead center. The E edge seemed to have a sharper drop-off in brightness than the rest. The low power 37X view showed a line of 4 stars to the SSE.


Slightly larger and slightly brighter than its neighbor M69, M70 is about the same distance--29,300 light years--and is 68 light years in diameter. The core of M70 is extremely dense and is noted to have undergone a core collapse at some point in its history. It is moving away from us at the rapid clip of 200 km/sec. Charles Messier described it in 1780 as a "nebula without star." William Herschel was the first to resolve the cluster into stars and described it as "a miniature of M3". Comet Hale-Bopp was discovered near M70 in 1995 as Alan Hale and Thomas Bopp were observing the cluster.

SubjectM70/NGC 6681
ClassificationGlobular Cluster
PositionSagittarius [RA: 18:43.2 / Dec: -32:18]*
Date/Time10/3/04 - 8:40 PM
Observing Loc.Flagstaff, AZ - Home
InstrumentOrion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag.32 mm (37X); 10 mm (120X)
TransparencyMag 4.5

* Based on published data.

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This page contains a single entry by Jeremy Perez published on October 3, 2004 8:40 PM.

Messier 6 - Butterfly Cluster was the previous entry in this blog.

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