Five members from the observing group, of Macclesfield Astronomical Society, were able to witness the disappearance of the 4.8 magnitude star Zeta Arietis by the dark limb of the Moon on Friday 14th January 2011.
It was touch and go whether or not we would actually see the event. The skies were, by 22:30 becoming very milky, making Zeta Arietis difficult to see visually.
I timed the disappearance at 23:06, whilst observing through my 10" Orion Optics Dobsonian with a 24-8mm Vixen LV zoom (16mm) X75.
The location was Kerridge Cricket club, Kerridge, Bollington, Cheshire. The NLM here is normally +5.6 but tonight, we were struggling to see +3 because of the approaching cloud but also the wide gibbous Moon. The seeing was variable ANT IV.
The observers were.
Chairman: Andrew Greenwood WO Zenith star 66 "OG"
Paul A Brierley 10" OD250 f4.8
Paul Canon 4" Celestron "OG"
John Tipping Home built 6" Newtonian
Richard Lowe 8" Meade LX200.
We all confirmed the disappearance at 23:06. And we were all greatly relieved when the star finally disappeared . The Moon was, by 23:04 beginning to make some of the observers eye's water, because of the intense concentration needed, to see the slowly fading star. We had all been watching from 22:50.
Occultation observing and timing is one of the few aspects of Amateur Astronomy that doesn't require any high tech equipment or knowledge. All you need, especially for Lunar occultations are an accurate time piece, (in my case I have a radio controlled watch) and a telescope ( minimum aperture 2") or large tripod mounted binoculars.
Below is a link, to the SPA's Occultation section web site, which gives you a full listing of occultation event's concerning the Moon.
http://www.popastro.com/sections/occ/lunarocc.php
