Our third attempt to observe a grazing lunar occultation was unsuccessful, but all agreed that the night of observing was still a big success.
It should be noted that the Clear Sky Clock said that it would be overcast all night, but our favourite weather goddess said that it would clear later in the night. So who are you going to trust? That’s right, so even though it was snowing at the time, Jim W., Jackie F. and I agreed to meet Don P. at Binbrook for the occultation, with the knowledge that it would clear eventually. As Don and Jim set up at the windsurfing parking lot in the park, which was about 500 meters closer to the center line than the hill, Jackie and I searched the skies for the moon with our binoculars. A few brief glimpses of our nearest neighbour through the clouds kept our spirits up, but we knew that there was to be no 7.8 magnitude stars cutting through the overcast. By occultation time there was not even a hint of the moon, and we could do nothing but console each other with the knowledge that this time we had at least seen the moon, which was better than the last two attempts.
Don brought his field kettle, Jackie brought hot cocoa and Jim brought his propane heater, and so after a goodly long while in the cold and dark we huddled together to warm ourselves, inside and out. My thanks to all for making this chill night more warm and bearable.
As the night wore on a small break to the north gave us the promise of seeing Comet Holmes, and soon all binoculars were searching the skies. As if Binbrook held some magical quality, a large and very transparent hole appeared directly over the park and stayed there for the remainder of the night, allowing us to observe the comet and many other wonderful sights. The comet was directly beside Mirfak, and as I had not seen it for a few days, I was interested to see how it had changed. It was barely visible to the naked eye, partly because it has been dimming, but also partly because of its proximity to Mirfak, which cast enough glare to interfere with the comet. Don’s little achromat showed a lovely disk to Mars, and we were able to discern dark surface markings, a sure sign that Mars is nearing its closest approach in a little over a month, and a testament to the fine optics of Don’s scope. The open clusters of the winter constellations, the Andromeda galaxy, the Pleiades, and a good look at not just the great nebula, but all the regions in the sword of Orion were part of a fine night of observing through Don’s scope. The seeing was excellent and the transparency was good too, as we could pick out the winter Milky Way quite easily. Don may have even spotted Uranus through the clouds that surrounded our magical window over the park – not an easy feat! Jim put his scope to good use by obtainig some fine images of the moon, which he shared with the rest of us. Finally, we were able to observe both the moon and the star that had earlier been occulted, thus bringing us one step closer to our first successful grazing occultation session.
We carried our good spirits to the nearest Tim Horton’s for the traditional observer’s doughnuts and coffees, and finished a fine night with good conversation and company. Indeed, another successful occultation expedition for the HAA.
Update by Don Pullen
Excellent report John and my thanks for doing this.
It really was a good night. It was the cloest we’ve come to having success with a lunar grazing occultation in our 3 attempts. As John indicated, we saw the moon peaking through the clouds up to half an hour before the time approached, but then we got socked in by clouds. By the time they cleared over the moon again an hour after the time for the occultation, we could see the star approximately 1 moon diameter away. So close. Next time we’ll nail it!
I had a great time with Jim, Jackie and John. I guess the afternoon snow scared everyone else away, but when the hole opened up, we had very steady skies and great seeing for several hours. We even saw a few meteors whose radiant appeared to be the early stages of the Leonids. Well worth the trip and cold temps. We were lucky that there wasn’t any wind until late which helped to keep the low temps more bearable.
I can hardly wait for our next try. At least we’re getting closer and eventually we’ll bag a proper grazing occultation. My thanks for the fun company last night – we really do have a great observing and sociable club.
