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ETX-105PE troubleshooting,
Green Laser Pointer, SQM-L, DSO observing

Posted: 11 November 2014

As I reported on my 4 November 2014 session report, I had a never-before-experienced problem with the AutoStar #497 on my ETX-105PE. For some reason the AutoStar seemed to be using Spring alignment stars even though my site settings (date, time, location) were all correct. It was only when I switched to using Universal Time (with the proper UT offset of 0h) that the alignment stars were correctly chosen. On the morning of 10 November I did some troubleshooting indoors but could not determine the cause. In local time mode, the AutoStar was about 10 hours off. I swapped to another AutoStar #497 and it also experienced the same problem. Changed the second AutoStar to use UT and it worked properly. Changed it back to use local time and it worked correctly this time. Powered off the ETX and powered it back on to check that the non-volatile RAM was retaining the correct site settings; it was. The alignment stars were correctly chosen. But since I swapped the AutoStar on the ETX I would need to do a TRAIN DRIVES to configure the AutoStar to this ETX (also needed to do a CALIBRATE MOTOR, which was done). Rather than do the TRAIN DRIVES in the daytime on a distant terrestrial object, I decided to do it shortly after opening the observatory on the next session and would use Polaris for the TRAIN DRIVES operation. I could then confirm that GOTOs were all correct.

Opened: Monday, 10 November 2014, 1806 MST
Temperature: 70°F
Session: 746
Conditions: Clear

Set up the ETX-105PE on the observatory patio:


Did an Automatic Align; stars correctly chosen and placed near red-dot finder. Align was successful. Did a GOTO Polaris; it was placed near the center of the 26mm eyepiece field-of-view (FOV). Did the TRAIN DRIVES on Polaris. Then did a GOTO Mars; it was placed near the edge of the FOV. Did a GOTO M13 in Hercules; it was placed near the center of the FOV. 1832 MST: completed the ETX tests and I'm now satisfied that whatever caused the problem on the 4th has been resolved.

1843 MST: powered on the 8" LX200-ACF. Then began testing a just received Green Laser Pointer which was donated by OPT to the Oracle Dark Skies Committee in recognition of Oracle State Park being designated as an "International Dark Sky Park" by the International Dark-Sky Association.


It worked great from my dark sky site. This handheld photograph, taken with my D7000 DSLR, f/5, 3 seconds, ISO 3200, shows the constellations of Andromeda and Pegasus with the laser pointer beam of light:


The laser pointer will be used at star parties at Oracle State Park. Thanks OPT!

1858 MST: viewed NGC125 (open cluster) in the constellation of Cassiopeia, 83X. Then added the f/6.3 focal reducer and William Optics Binoviewers. Began viewing open clusters in Cassiopeia: NGC129, NGC225, NGC457 (3D effect very nice), NGC559, M103, NGC654, NGC659, NGC663, M52, and NGC7789.

1928 MST: viewed the Double Cluster, focal reducer + Binoviewers. Simply lovely, with a nice 3D effect (fainter stars seemed further away than brighter stars).

Then did some tests with a Unihedron SQM-L light meter that was recently purchased by Oracle State Park for ongoing night sky quality measurements at the Park. There was some slight variability in measurements with the two light meters (one on loan from NOAO and the new one). Will do more tests over the coming nights.

1956 MST: viewed M45 (Pleiades), focal reducer + Binoviewers. Great view with all stars inside the FOV and extending across nearly the entire FOV. There were some hints of nebulosity visible. Some wind was now blowing.

2006 MST: slewed to Cygnus and began doing some DSO observing, focal reducer + Binoviewers. Viewed NGC6819 (Foxhead Cluster, open cluster; faint but pretty), NGC6888 (Crescent Nebula; hint of nebulosity), and M29 (open cluster). At 2012 MST, while viewing M29, saw two polar orbiting satellites pass through the FOV. Continued to observe Cygnus DSOs: NGC6960 (Veil Nebula; faint nebulosity), NGC6992 (nebula; easily seen), and M39 (open cluster). Returned to NGC6992 and added a 1.25" O-III filter to the Binoviewers. View of the nebula was slightly improved. But the filter did not help with seeing NGC6960 (Veil) and NGC6888 (Crescent).

2033 MST: viewed M57 (Ring Nebula), focal reducer + Binoviewers + O-III filter. No improvement with the filter; the Ring Nebula was better without the filter.

Tried for M1 (Crab Nebula). It was visible with the focal reducer + Binoviewers but was too low for good viewing.

Did observing of open clusters in Auriga, focal reducer + Binoviewers: NGC1664, NGC1857, NGC1893, NGC1907, M38, M36, and M37.

2053 MST: eastern sky beginning to brighten due to soon-to-rise waning gibbous moon. 2059 MST: quick look at M37 (open cluster), 83X.

Closed: Monday, 10 November 2014, 2111 MST
Temperature: 59°F

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