Magnitude +2.9 star Mu (μ) Geminorum, better nown as Tejat in the constellation of Gemini, is occulted (hidden) by the rising 13-day-old waxing gibbous Moon early on the evening of Thursday, 9 January 2020 as seen from the British Isles. This graphic shows the event’s progress as seen from London and Edinburgh, clearly demonstrating the effect of geographical latitude. AN graphic by Ade Ashford.If the early evening sky of Thursday, 9 January is clear, observers in the British Isles get the opportunity to witness a conspicuous naked-eye star slip behind the rising waxing gibbous Moon. Magnitude +2.9 Mu (μ) Geminorum, with the proper name Tejat, lies near the western edge of the constellation Gemini. The precise time and duration of the star’s disappearance behind the Moon – an event known as a lunar occultation, from the Latin occulo, ‘to hide’ – depends on where you live in the UK.
Observers in London will see, weather permitting, Tejat disappear at the darkened limb (edge) of the 13-day-old Moon shortly after 5:05pm GMT (17:05 UT) and reappear at the bright lunar limb 45 minutes later. For a skywatcher in Edinburgh, the star’s corresponding disappearance and reappearance times are a few seconds before 5:17pm GMT (17:17 UT) and 5:52pm GMT, respectively.
Mid-occultation of Tejat takes place with the Moon some 15 degrees (about a span-and-a-half of a fist held at arm’s length) above the UK’s east-northeast horizon. While it is an easy spectacle to follow in a small telescope, the star’s reappearance at the bright lunar limb might be a challenge for binocular users. As with all occultation observations, it pays to be setup and scrutinising the Moon 10 minutes before the predicted times, particularly if you live some distance from either London or Edinburgh.
The serene beauty of the International Space Station sailing silently overhead needs nothing more than the naked eye to appreciate. But when the dazzling ISS is also in conjunction with a pair of prominent Solar System bodies — such at the Moon and Saturn on the night of 2 August 2017 in the UK — you may wish to grab your binoculars and look low in the south-southwest just before 11:20pm BST.
Lunar swirls have been the source of debate for years. The twisting, swirling streaks of bright soil stretch, in some cases, for thousands of miles across the Moon’s surface. Brown University researchers have produced new evidence that they were created by several comet collisions over the last 100 million years.
Skywatchers in Western Europe looking in the southern sky at dusk on Thursday, 18 October can see the 9-day-old waxing gibbous Moon close to the upper left of Mars, the pair fitting comfortably in the same field of view of typical binoculars. This is also a good night for spotting some prominent martian features telescopically – seeing permitting!
