Links I found useful as I worked on the program
Astronomical League's page for the Globular Cluster Program Astronomical League YouTube video on the Globular Cluster Program Globular Clusters that defined the class (click on the image to get full size pic of object) Messier Globular Clusters (click on the image to get full size pic of object)Shapley-Sawyer Concentration Class Descriptions
| Class | Description |
|---|---|
| I | High concentration of stars towards the center (M75) |
| II | Dense central concentration of core stars (M80) |
| III | Strong inner concentration of core stars (M54) |
| IV | Intermediately rich concentration of core stars (M15) |
| V | Intermediate concentration of core stars (M13) |
| VI | Intermediately mild concentration of core stars (M3) |
| VII | Intermediately loose concentration of core stars (M22) |
| VIII | Rather loose concentration of core stars (M14) |
| IX | Loose concentration of core stars (M12) |
| X | Very loose concentration of core stars (M68) |
| XI | Almost no concentration of core stars (M55) |
| XII | No concentration of core stars (Palomar 12) |
The Pin
Summary in Astronomical League Program Order
Completed 50 observations one of which was a challenge object
Recorded Observations in the order that they were made
Transparency is the truncated magnitude of the dimmest star I can see. Seeing is rated from 1 to 5 with 1 being perfect. I rarely attempt making observations unless conditions are pretty good. So there is not much variation in reported conditions.Telescope used - Celestron 8" Nexstar Evolution
Eye Pieces used
Explore Scientific 24mm for 85x, Delos 14mm for 145x, Delos 10mm for 200x, Delos 8mm for 256xAL#49 (M79) NGC1904 - Shapley-Sawyer Class V
AL#67 M3 (NGC5272) - Shapley-Sawyer Class VI
Challenge Object - AL#59 NGC 4147 - Shapley-Sawyer Class IX
Includes a sketch of the star field where the cluster is located and another sketch showing the cluster in the eyepiece.
| This is a challenge object where the AL program guide says magnitude 9.9, SkySafari says magnitude 10.3 and Wikipedia says magnitude 10.7. At 85x I can barely see the cluster as a dim fuzzy patch and made a sketch showing the cluster in its star field. At 145x and the view was pretty much the same with no new detail noted. At 203x the fuzzy patch seemed to be elongated and I made a detailed sketch. There was some brightness near the bottom (South West) of the cluster - which seemed to come and go due to seeing. Overall, the cluster was fairly nebulous almost like an elliptical galaxy - I could not resolve any individual stars. The brightness I observed seemed to be about a third of the width of the fuzzy patch. Based on the comparison pictures of the program guide and descriptions I thought it matched "Class IV - Intermediately rich concentration of core stars" and I estimated this to be a class IV cluster since the brightness appeared to be pretty concentrated. |
Starfield sketch at 85x (using my 24mm ES68 eyepiece) showing where the cluster is located
Cluster detail sketch at 203x (using my Delos 10mm eyepiece)
AL#64 M53 (NGC5024) - Shapley-Sawyer Class V
AL#77 NGC5904 M5 - Shapley-Sawyer Class V
AL#92 M13 (NGC6205) - Shapley-Sawyer Class V
AL#106 M92 (NGC 6341) - Shapley-Sawyer Class IV
| Observed from Chippokes State Park during the Back Bay Amateur Astronomer's Spring East Coast Star Party. M92 although smaller than M13 it is pretty close in apperance to M13 so I spent some time going back and forth between the two. At 85x the cluster is located in a very nice field of stars and is quite beautiful with many stars resolved. I can resolve stars across the face of the cluster except at the very center. Appears uniformly round, no noticable dark lanes. At 203x it is still beautiful although tonight I am not getting that 3D sensation I sometimes get from it and M13. |
AL#94 M12 (NGC 6218) - Shapley-Sawyer Class IX
AL#85 M4 (NGC 6121) - Shapley-Sawyer Class IX
AL#84 M80 (NGC 6093) - Shapley-Sawyer Class II
AL#173 M56 (NGC 6779) - Shapley-Sawyer Class X
AL#90 M107 (NGC 6171) - Shapley-Sawyer Class X
AL#96 M10 (NGC 6254) - Shapley-Sawyer Class VIII
AL#111 M10 (NGC 6356) - Shapley-Sawyer Class II
AL#163 M22 (NGC 6656) - Shapley-Sawyer Class VII
AL#99 M62 (NGC 6266) - Shapley-Sawyer Class IV
AL#100 M19 (NGC 6273) - Shapley-Sawyer Class VIII
AL#185 M15 (NGC 7078) - Shapley-Sawyer Class IV
AL#186 M2 (NGC 7089) - Shapley-Sawyer Class II
AL#125 M14 (NGC 6402) - Shapley-Sawyer Class VIII
AL#147 NGC 6544 - Shapley-Sawyer Class IV
AL#108 M9 (NGC 6333) - Shapley-Sawyer Class VIII
AL#158 M28 (NGC 6626) - Shapley-Sawyer Class IV
AL#157 NGC 6624 - Shapley-Sawyer Class VI
AL#159 M59 (NGC 6637) - Shapley-Sawyer Class V
AL#187 M30 (NGC 7099) - Shapley-Sawyer Class Not Available
AL#132 NGC 6441 - Shapley-Sawyer Class III
AL#165 M70 (NGC 6681) - Shapley-Sawyer Class V
AL#167 M54 (NGC 6715) - Shapley-Sawyer Class III
AL#177 M55 (NGC 6809) - Shapley-Sawyer Class XI
AL#182 NGC 6934 - Shapley-Sawyer Class VIII
AL#180 M71 (NGC 6838) - Shapley-Sawyer Class X
AL#181 M75 (NGC 6864) - Shapley-Sawyer Class I
AL#166 NGC 6712 - Shapley-Sawyer Class IX
AL#169 NGC 6723 - Shapley-Sawyer Class VII
AL#162 NGC 6652 - Shapley-Sawyer Class VI
AL#33 NGC 288 - Shapley-Sawyer Class X
AL#155 NGC 6569 - Shapley-Sawyer Class VIII
AL#183 NGC 6981 (M72) - Shapley-Sawyer Class IX
AL#148 NGC 6541 - Shapley-Sawyer Class III
AL#149 NGC 6553 - Shapley-Sawyer Class XI
AL#141 NGC 6522 - Shapley-Sawyer Class VI
AL#48 NGC 1851, C73 - Shapley-Sawyer Class II
AL#62 M78 NGC 4590 - Shapley-Sawyer Class X AL number mislisted on sheet. It should be AL# 62
AL#74 NGC 5824 - Shapley-Sawyer Class I
AL#81 NGC 5986 - Shapley-Sawyer Class VII
AL#101 NGC 6284 - Shapley-Sawyer Class IX
AL#103 NGC 6293 - Shapley-Sawyer Class IV
AL#104 NGC 6304 - Shapley-Sawyer Class VI
AL#105 NGC 6316 - Shapley-Sawyer Class III
This page last updated on 7/12/2025 2:38:05 PM. If you have comments or suggestions, email me at webmaster@jscheetz.com