Cassiopeia Observatory logo

Two Messier Catalog Open Star Clusters

Posted: 24 June 2017

Open: Friday, 23 June 2017, 1930 MST
Temperature: 89°F
Session: 1128
Conditions: Mostly clear

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
Binoviewers 20mm eyepiece
1.6X Barlow Lens

D7200 DSLR

The new air conditioner is doing its job. The temperature inside the observatory seems to stay below the outside air temperature during the hottest time of the day. Wayne Parker at SkyShed Observatories said I should add a 3/4" foam backer rod tube to the gap between the dome and walls after closing the dome to mitigate the overworking of the air conditioner. The purpose of the rod is to keep cool air inside the POD. I will pick up a 20' section on my next trip to Home Depot. Until then I plan to just turn off the AC unit at night and back on in the morning during this current heat wave.

1936 MST: AC OFF (manually).

1938 MST: sunset.

1942 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Jupiter, 102X. The Great Red Spot and the four Galilean Moons were visible. The view was great. Switched to the William Optics Binoviewers. At 122X and 195X the view of Jupiter was awesome through the Binoviewers.

Having the air conditioner running during the hot daytime has dramatically reduced the telescope cool-down time, making for incredible views through the 12" telescope immediately after opening the observatory.

2011 MST: viewed Saturn, low and through a tree, Binoviewers 122X. Not a good view (yet).

I then did some planning for imaging some Deep Sky Objects (DSOs) for my Messier Catalog photo album update. Decided to image M18 and M21 open star clusters this night. Prepared the D7200 DSLR for imaging.

2032 MST: viewed Saturn again, which was now out from behind the tree but was still too low for good viewing. Using the Binoviewers at 122X Cassini Division and three moons were visible. 2100 MST: the view of Saturn was a little better as it rose higher in the sky.

Viewed Omega Centauri (globular cluster), Binoviewers 122X, very low in the southern sky. Unfortunately, it was way too low (near setting from my location) for a good view.

2108 MST: viewed M57 (Ring Nebula, planetary nebula), Binoviewers 122X. Wow, what a view! The Ring was a glowing green object.

2110 MST: the first of two Kissing Bugs seen this night was terminated.

SYNCed the AutoStar on the star Antares and then viewed the globular cluster M4, Binoviewers 122X. Another nice view.

2124 MST: viewed the open clusters M18 and M21, Binoviewers 122X.

Mounted the D7200 DSLR at prime focus + focal reducer, focused on the star Antares, and locked the primary mirror using the mirror lock bolt. I used a small socket wrench to tighten and loosen the bolt. This was more convenient than using my fingers, which is what I had been doing for the past year. Glad I though of it!

Returned to M21. 2137 MST: StarLock ON.

Took these photos, StarLock autoguided, 30 seconds, ISO 1600, White Balance 3570K:

M21 Open Star Cluster

M18 Open Star Cluster

2149 MST: StarLock OFF. Ended imaging as seeing had begun to deteriorate.

Viewed Saturn, now higher in the sky, Binoviewers 122X and 195X. Nice view. Four moons were visible now.

2202 MST: Kissing Bug #2 terminated.

2207 MST: final look at Saturn, 102X.

2208 MST: LX600 OFF.

Close: Friday, 23 June 2017, 2220 MST
Temperature: 82°F
Session Length: 2h 50m
Conditions: Clear

Comments are welcome using Email. Twitter users can use the button below to tweet this report to your followers. Thanks.

Previous report

Cassiopeia Observatory Home Page

Back to Top

Copyright ©2017 Michael L. Weasner /