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Shortly before sunset on March 29 the magnitude 1.4 star Regulus (alpha Leonis) will be occulted by the Moon. With your back to the Sun look at the gibbous Moon in the SE sky and at around 18:15 UT Regulus will disappear at the Moon’s dark limb (DD). About an hour later it will reappear at the bright limb (RB).
The attached table gives the predicted times for various locations around the UK and IE. The diagram indicates the DD and RB positions on the lunar disc for the locations in the table. (All computed using Occult software). Slightly less accurate times can be derived from stations’ a and b coefficients (given in the table) using the method on page 37 in the 2026 BAA Handbook. Planetarium programs can also be used.
The DD event should be observable with any optical aid, despite the glare from the 89% illuminated Moon. Regulus, a blue-white subgiant, is a multiple star system and a telescope might show its mag 8 companion Regulus B, 3 arcmin distant, which will be occulted about 5 and a half minutes before Regulus A. Most lunar occultations are instantaneous; expect a very brief fade of 0.1s with Regulus. The RB event will be a more challenging observation against the surface brightness of the lunar limb.
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Clouds, rain and strong cold winds today. The sky improved about 20 mins before the DD. so I could align my C11 on the Moon. Clouds raced in again, only giving me naked eye glimpses, then more rain just at DD time.
Thick cloud cover at RB time followed by heavy rain.
So much for British ‘Summer’ Time.
Alex.
Alex, Much the same conditions here in Oxfordshire. I didnt get a glimpse of the Moon at all !
Sorry to stay the shutters remained closed
TimSkies cleared in Nottingham nicely and the clouds were kind at the two crucial moments. The main issues was a very strong blustery wind buffeting the telescope!
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