Canada/USA Astronomical Seeing Observation Program

Astronomical-Seeing Observation Details

1. Observer
Brian J. Hatley
2. Site
N47.48 W122.07 (N47°29' W122°04')
3. Scope
10 inch F/4.7 Mirror. Open top. Open bottom. Fan cooled: Yes.
4. Time
2007-10-28 06:30:00 PDT (GMT -7)
2007-10-28 13:30:00 UTC
5. Observing Conditions
400X. 55.0° up. Was cooling for 1h00m.
Appearance of out-of-focus star: Slow flicker
6. Seeing Observation
Star Image II (2 out of 5)
8. CommentsMirror matched ambient temperature.

Planetary observation session - Mars at 56 degrees, Saturn at 46, Venus at 36.

Able to see semi-clear features on Mars intermittently. The seeing conditions caused the entire disc move around slightly (perhaps 10% of the Martian disk diameter). Saturn had a several 10-30 second periods of time where the Cassini devision was visible and clear, and the different brightnesses of the inner and outer rings were visible and distinct, including the portion crossing the planet (pretty narrow since the rings approaching edge-on.) Could also see cloud bands on the planet. Venus was turbulent nearly all the time, with a couple of clear glimpses.

Another interesting aspect of the seeing this session, is the focus seemed to change every few minutes, and this would be coincident with a change/shift in seeing conditions. My scope has a focus lock (used this morning), so I don't think it's the scope, but thought I'd mention it as it's the first time I've seen this phenomenon, and thought it may say something additional about the seeing. (I'll also be double-checking the focuser).

Excellent site. I trust it far more than the regular weather forcasts - it was spot-on this morning (except seeing was a little optimistic.)

Hope this helps,

Brian
Date Entered2007-10-28 17:07:07 UT

Show on map
Any: First | Previous | Next | Last
By Brian J. Hatley: First | Previous | Next | Last
Index by Author | Index by Day | All


Seeing Observations Home | Clear Sky Chart Home