by Tom Swords

The images that AAAP members have captured and animated are a true visual record of the event, inspiring and amazing.

I did something different. I watched the eclipse and recorded the temperature!

I had two telescope rigs set up here in Ewing. A 60mm finder scope with Baader solar film and a 14mm TV Radian for white light viewing that was mounted on a Ioptron Minitower (previously owned by the late Gene Ramsey). 

The other instrument was a Lunt LS50 Hydrogen Alpha telescope mounted on an Ioptron AZMP.  The LS50 had a ASI585 camera mounted with no filters. I used ASI Capture on a HP laptop to send live screen video to a 48” monitor inside our kitchen where it was nice and dark!

I had assembled, calibrated and tested all the equipment the previous day.

We sat and watched the monitor to observe first contact at 2:09. For the next hour we switched between indoor to outdoor for white light views. Waiting outside for the last moments prior to the maximum partial totality to arrive, we observed birds returning to their roosts. The light was dimming into grey. Shadows from tree leaves were making crescents. The moon covered the sun to 89.2% at 3:24 PM…at which time the heavy clouds arrived!

I saved no direct camera images of the eclipse but it looked great on the monitor indoors. I had first adjusted the scope to show solar prominences but retuned to show surface details as it looked better for an eclipse. I learned quite a bit about pressure tuning, adjusting the gain and exposure with the histogram tool in ASI Cap to optimize the view.

I had set up a data logger to record the temperature over the duration of the eclipse.

IBM 440SThinkPad, Elitech-RC-5 Temperature recorder, Elitech software, Data was exported as PDF and XLS.

The data recorder was in the shade suspended in air 15 inches away from any surface.

Here is the result recorded at 1minute intervals beginning at 1:54 PM to 4:34PM. Note that the chart times are in 24Hr format.

It was quite sunny and rapidly warming at the time of the data run start (1:54PM). The temperature rose 1 degree to 69.80 Deg after first contact at 2:09 PM but then began to steadily decrease. At the time of maximum partial totality (89.2% at 3:24 PM) the temp was 63.50 Deg and still decreasing. After an additional 5 minutes the temperature dropped to the lowest point of 63.10 Deg. 

The temperature remained at 63.10 Deg until 3:35PM and thereafter began to rise. At 4:22 the temperature was 65.50 Deg and the recorder was stopped. It was now very cloudy and a brief rain shower occurred.

Summary: A measured change of 6.7 Deg due to an 89.2 percent reduction of the suns light. There was a delay of 5 minutes between the max totality and the lowest temperature. The duration at the low of 63.10 Deg was 6 minutes.

Please contact me if you would like a copy of the PDF or Excel data sheets.