Cassiopeia Observatory

ETX-105PE & 8" LX200-ACF Observing,
Planets & Moon Imaging
Posted: 11 March 2012

I opened Cassiopeia Observatory on Saturday, 10 March 2012, at 1740 MST, 71°F. At 1749 MST, viewed Venus at 77X in the 8" LX200-ACF. I again set up my ETX-105PE outside of the observatory:

At 1803 MST, I set up the D7000 DSLR at prime focus + 3X TeleXtender on the 8" telescope for a video recording of Venus, 1/320sec, ISO 5000. Seeing was not very good; it was very difficult to focus on Venus. This is a cropped frame from the video:

I then began trying to view Mercury, and at 1820 MST, shortly before sunset, I got it at 77X. I SYNCed on this location, mounted the camera at prime focus + 3X TeleXtender, slewed to Venus for a focus test, and then back to Mercury's RA/DEC. Unfortunately, I was not able to see Mercury in the camera viewfinder and get it into the camera FOV until 1848 MST. It was now very low and really blurring out. I did a video recording at 1/200sec, ISO 5000. This is a cropped frame from the video and at the same scale as the Venus image:

At 1848 MST, I returned to observing with the 8" telescope. Viewed Mercury at 206X. I then had to replace the battery in the observatory digital thermometer; first time since getting it 8 August 2009. Next, I SYNCed on the star Aldebaran to correct the earlier SYNC on Mercury's position. I then viewed Jupiter, 77X and 206X, at 1908 MST. Then slewed to Mars, low in the east, and used 77X and 133X. Mars was still too low for good viewing and no details were visible.

Beginning at 1915 MST, I began the ETX-105PE Auto Align. After centering the first alignment star, Sirius, the 2nd alignment star, Capella, was just at the edge of the 26mm (56X) eyepiece FOV. After completing the alignment, all objects were nearly centered at 56X. I spent the next 35 minutes using the ETX-105PE at 56X. I viewed Mercury, Venus, and Jupiter. Since I had not done it in a long time, I checked the collimation using the star Betelgeuse; it was good. Then viewed Mars; the view was pretty good at 56X. The North Polar Cap was barely visible but the "sunrise cloud" was clearly seen. A dark surface area was also visible. I then began some DSO observing with the ETX-105PE: M42, M45, M31, Double Cluster, and M51. I tried to view M66 but it was currently in the tree. I put the ETX to sleep and returned to the 8" at 1950 MST.

I viewed Mars at 133X. Seeing was still not very good; I added the moon filter which helped. I looked up from inside the observatory; the Winter Milky Way was very pretty, running from Cassiopeia in the northwest, overhead, and down past Canis Major in the south. At 2005 MST, using 133X + moon filter, I could now see Utopia, Mare Cimmerian, and Mare Tyrrhenum on Mars.

At 2015 MST, I began some DSO observing with the 8" at 77X. Viewed the Leo Triplet of galaxies (M65, M66, and NGC3628). All were in the FOV at 77X. Then went to M51, the Whirlpool Galaxy.

At 2100 MST, I went back to using the ETX-105PE. Viewed Mars, then the Leo Triplet of Galaxies. All three galaxies were visible in the ETX at 56X and in the same FOV. I then viewed M51 again, now a little higher in the sky, followed by M81 and M82. Both M81 and M82 were in the same FOV at 56X. At 2110 MST, viewed Comet C/2009 P1 (Garradd) in the ETX-105PE. A nice coma was visible at 56X.

I returned to the 8" and viewed M81 and M82; both galaxies viewable in the same FOV at 77X. At 2120 MST, I viewed Comet Garradd in the 8" at 77X. The nucleus and coma were easily seen and there was a hint of a tail visible using averted vision. Since the moon would be rising shortly, I deferred comet imaging to the next session.

At 2135 MST, the eastern sky was beginning to brighten from the rising waning gibbous moon. I returned to Mars, 206X + moon filter. Syrtis Major was coming into view. I decided to try some more Mars imaging. I mounted the D7000 DSLR at prime focus + 3X TeleXtender and did a focus test on the star Regulus using the Bahtinov Mask. I did a series of video recordings at various shutter speeds and ISO settings. This Mars image is a stack of 881 frames, 1/320sec, ISO 3200, cropped, and upscaled 200%:

At 2202 MST, I resumed Mars observing, 206X + moon filter. Mars was looking very good now. At 2210 MST, switched to 364X (no moon filter). The view was good during moments of steady seeing. I tried using 1091X and 619X but the seeing was not quite good enough for that much magnification on the 8". But at 400X, the view of Mars was impressive at times.

At 2242 MST, the moon was rising over the hill but was still behind a tree. Saturn was visible but behind the same tree. Took a quick look at Saturn, 77X, at 2307 MST, through the tree branches. I set up for some video recording test exposures with the D7000 DSLR at 8" prime focus + 3X TeleXtender. Used 1/200sec and 1/125sec at ISO 6400. Unfortunately, they were too underexposed.

At 2320 MST, I went back to the ETX-105PE and viewed Saturn at 56X. Then viewed the moon at 56X in the ETX. Next, I mounted the D7000 at prime focus of the ETX-105PE and took some images of the moon. This is a 1/500sec, ISO 800, exposure:

At 2334 MST, returned to the 8" telescope and viewed Saturn at 206X and 364X. Good views. Then did some lunar observing at 364X, 206X, 133X, and 77X. Began closing up at 2347 MST.