Cassiopeia Observatory logo

ETX-70AT Observing, 8" LX200-ACF DSO Observing

Posted: 11 February 2012

I opened the observatory on Friday, 10 February, at 1806 MST, 73°F. The sky was clear and since the moon would not rise until later, I set up the ETX-70AT for some wide field observing once twilight ended:


I used the 8" LX200-ACF to view Venus at 77X at 1813 MST. Uranus, which had a close conjunction with Venus on the previous night, was not visible yet. At 1820 MST, viewed Jupiter at 77X, 133X, and 206X; four moons were visible. I then returned to Venus. At 1825 MST, slewed to Uranus, which was now visible well away from Venus.

At 1840 MST, I powered on the ETX-70AT and started an Easy Align. While it was slewing to the first alignment star, there was a Motor Unit Fault error. Since this can happen when battery power is low, I did a CALIBRATE MOTOR, which will sometimes cure the problem (unless the battery power is very low). Started the Easy Align again and got another Motor Fault Error. I opened the battery compartment and took out the battery holder. Oops, one of the AA batteries had leaked. I went back to the house, removed the batteries, cleaned the holder, and inserted fresh AA batteries. At 1853 MST, I was back at the ETX. Powered it on and did an Easy Align. Whew, all was well this time. I did a GOTO M42 in Orion and then began waiting for twilight to end.

I monitored the western sky to see when the Zodiacal Light would become visible. It was faintly seen at 1908 MST. The Zodiacal Light was a slightly tilted, tall, narrow, "isosceles triangle" of faint light going from the horizon in the west up to Venus, continuing on to Jupiter, where it faded out.

At 1928 MST, viewed M42 in the 8" at 77X. I then started observing with the ETX-70AT using the standard 25mm eyepiece (14X). Viewed M42, M31, M45, M44, and the Double Cluster. I tried for the Flame Nebula but did not see it. I was able to see some faint nebulosity where the Horsehead Nebula is located but did not see the Horsehead itself. (I did not expect to see the Horsehead with such a small aperture telescope.) I then took a tour along the Winter Milky Way from Canis Major to near Auriga. The views of the star fields in the ETX-70AT were very nice. I ended ETX observing at 2007 MST.

2020 MST; back to Jupiter in the 8" telescope. Beginning at 2030 MST, I used Observer Pro on the iPhone to check for currently visible DSOs. I would find an interesting one in Observer Pro and then attempt to view it at 77X in the 8" telescope. If the object looked good, I added it to my imaging list for future sessions. Observed the following DSOs:

NGC1600: galaxy, faint
NGC1501: planetary nebula, large but faint
NGC1569: galaxy, small, faint, but interesting
NGC1637: galaxy, faint but large
NGC1535: planetary nebula, small (previously imaged)
NGC2261: Hubble's Variable Nebula, small but nice
NGC2217: galaxy, small, faint, but interesting

I ended DSO hunting at 2140 MST. Returned to Jupiter but it was too low for good viewing. I then went to Mars and viewed it at 77X and 206X. It was too low for good viewing, but the North Polar Ice Cap was visible.

The eastern sky was beginning to brighten due to the rising waning gibbous moon. And the neighbor to the north did his part to contribute to the worldwide light pollution problem by turning on his nuisance floodlights. I took a quick look at M42 and then began closing up for the night.

Closed the observatory at 2206 MST, 52°F.


Go to the previous report.

Return to the Cassiopeia Observatory Welcome Page.

Copyright ©2012 Michael L. Weasner /