7/18/18 10:15 pm 70 degrees, 50% RH, slight breeze S 3/5 T 4/5
(I could actually see some stars to the East of Saturn – very unusual)
Meade ETX 80 used in GoTo/tracking mode, Orion XT8i used manually Stellarium on the phone.
Baader Hyperion Zoom, Meade 82/5.5, ES 82/6.7, Daytson 2X, 3X barlows, GSO 1.5X 2” barlow element, #12, #21 color filters
- Test the ETX 80 to be sure it is in good working order for Thursday’s outreach event at the Old Westbury Gardens
- Try to see the moons of Saturn with the ETX 80
- Try to see the moons of Saturn with Orion XT8i
- Take another look at Mars
Position challenge - I had my phone open and Stellarium running, zoomed in on Saturn so that it showed me the moons. Position was more of an issue tonight than usual as I was not focused on the planet but on dim things around it. So how a refractor with a diagonal or a Newtonian would present the image would be different from what Stellarium was showing me and I would have to consider that as I tried to identify these little pinpoints of light as moons. A key thing to remember is that refractors flip the image left to right. Newtonian’s flip them top to bottom and left to right.
While writing this report I pulled up a diagram in “Turn left at Orion” which shows how the refractor and the Newtonian flip and turn the image. I kept it open to remind me of this effect to help me confirm my sightings. I think there is a way to have Stellarium change the image to match the scope but I don’t know how to do it. Will have to investigate that.
10:15 pm - Saturn ETX 80 – I have looked at Saturn with the ETX before. Other than a bit of chromatic aberration it puts up a pretty good image. But tonight I was not focused on the planet but on seeing the moons around the planet. Tonight the best images were with Meade 5.5 in 2X barlow, about 145X. Also good was ES 82 6.7 in 3X barlow, about 180X, but detail was better at 145X and I was able to pick up more of the surrounding pinpoints at the lower power.
* Enceladus ?
The seeing was OK and transparency was pretty good. I could actually see some stars to the left (SE) of Saturn which were probably part of Sagittarius. Normally there is nothing or maybe 1 random star, but tonight there maybe 12 dim stars to the left of Saturn. I did not explore them but it caught my attention as it is so unusual.
Titan was pretty distinct and I was confident of that one. I had a faint pinpoint at the point were I show Enceladus, but I am not sure as it would fade in and out and was only visible via averted vision. I was hitting the limits of the scope under these light pollution conditions. So I will call Titan a hit and Enceladus a maybe.
ETX 80 tracking was good. I was using the hand control to move Saturn around in the eyepiece to try having the planet at different angles to see if that would reveal detail. I also moved it just out of the FOV to see if that might help me see a faint pinpoint that could be a moon.
11:10 – Packed up the ETX 80 and took it back to the garage. Out came the Orion XT8i
11:29 = XT8i - Saturn – In the BH Zoom at 50X I could see Titan clearly, confirming by position against other stars in the field of view. But I could not detect any of the other moons.
After some zooming in and out and trying different eyepieces I had my best views in the ES 82 6.7/about 180x and my BHZ at 150X. I moved back and forth trying to tease out those tiny moons.
Titan was confirmed.
Rhea was confirmed and
Tethys was visible by averted vision, confirmed by position
Dione – I had a pinpoint come in and out in the position that would be Dione. I had to keep reminding myself that the image was flipped as I compared Stellarium and the eyepiece. It was fleeting, winking in and out as seeing changed focus but I am going to declare this one seen, even if it was fleeting.
I continued to play with eyepieces, moving Saturn out of view to see if I could get a better look at the moons. That helped with Tethys and Dione. I don't think I can confirm Enceladus but there was a rare hint of a pinpoint in the proper position. I won’t declare that one seen.
12:10 – Mars – Could not pack up without a peek at Mars. In fact tonight was the best view of Mars since 2016. Seeing was a bit better and the transparency was good. Mars was about 21 degrees above the horizon. The planet boiled but I was able to detect some variation in shading on the planet. Using the XT8i, the best view was again between the BHZ at 150X/.45 degree FOV and the ES 82 6.7 at 180X/.45 degree FOV. I barlowed the zoom but topped out around 7 mm (14X2) so about the same mag as the ES.
As I viewed the planet in the Newtonian, the lower right quadrant seemed to show a darker area than the rest of the planet. I saw a pinpoint to the right of the planet, about 20% of the FOV distant from the planet that I thought might have been one of the moons, but it was a star. Checking Stellarium later, the moons were much closer to the planet and would not have been visible.
I tried a #21 filter – no help
I tried a #12 filter, yellow, and this did help bring up that darker area just a bit, enough for me to feel confident that it was actually there.
12:30 pm – done
This was one of the very few times that I had pulled out two scopes, one after the other in an attempt to compare views. Clearly aperture wins as the XT8i pulls in 6.6X as much light as the 3.1” refractor. The difference was immediately obvious in the eyepiece.
Looking for the moons of Saturn represented the longest I can recall ever spending on one task/target with the possible exception of our moon. It was fun to chase these faint targets and work to translate and confirm by position around Saturn.
Glad I took a brief look at Mars. It was still a very disappointing target, but the best view I have seen this year.
Ed, the Cosmic Tourist