June Notley Stargazing – Solar Observing
Saturday 11 June saw half a dozen society members congregate at Great Notley Country Park for the latest in our series of public observing events. Due to the long summer evenings, the June, July and August events are concentrating on solar observing only.
The day got off to an inauspicious start when we arrived under a sky which was largely cloudy with only a few small breaks. Part way through setting up the telescopes, the weather took a turn for the worse as raindrops began appearing on the solar filters. Cue a couple of tarpaulins hurriedly thrown over the equipment! The shower was thankfully short-lived and amounted to no more than a passing sprinkle.
The first couple of hours provided little in the way of actual observing. We had four telescopes set up – the society’s Lunt solar scope and William Optics refractor, and two members’ Celestron C8 SCTs – but the sun remained a little elusive. The occasional glimpse just about provided enough time to realign the Lunt each time before the sun disappeared again. A few passers-by were curious enough to ask what we were up to, but the breaks in the cloud were few and far between and not many managed to actually see anything. Sitting under a cloudy sky at a public event is a fairly regular occurrence for us, so we consoled ourselves with tea on the lawn. There was an air of resignation knowing that the forecast was for the weather to get progressively worse.
The whole event looked set to be a let-down, but amazingly around 2.30pm the clouds began to break a bit. Blue sky began appearing and the sun began to show itself with increasing frequency. Disappointingly, there were very few sunspots on display. Only two or three very tiny ones were visible in the white light telescopes. The Lunt, on the other hand, provided some fantastic views of a series of spectacular prominences. One portion of the limb was particularly active with several huge prominences, one of which resembled a volcanic eruption. We were able to watch these prominences change shape throughout the afternoon. Still visible after two to three hours, they became visibly smaller, and the ‘eruption’ dissipated.
By mid-afternoon, the blue parts of the sky began to outnumber the clouds and the interest in our activities increased proportionately. We had a steady stream of visitors throughout the remainder of the afternoon, and all went away fascinated by what they had seen.
The day ended at about 5.00pm, far later than we had originally intended to stay, but once the sun finally started to deliver and the crowd started asking questions, the time just flew. We departed in the nick of time; just as we were packing up a large cloud was looming on the horizon. The rain started falling just as we left the park.
After a poor start, the day turned out to be a great success. That one word, “Wow,” uttered by someone taking their first look through a telescope makes the effort put into these events worthwhile.
If you think you may be able to help out at a future event, please consider doing so. You don’t need to own a telescope; extra hands to man the club telescopes are always welcome, as are people willing to chat to the public and answer their questions. The sky may not always co-operate, but regardless of the weather we normally end up having a good laugh together.
Dee provided a valuable lesson in why it is so important to only use specialised filters for viewing the sun. Dismantling her scope, she removed the solar filter while the scope was still pointing at the sun and managed to burn a hole in the lens cap she had used to plug the end of her telescope. It took a mere three seconds for smoke to appear!