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.
When a full Moon makes its closest pass to Earth in its orbit it appears up to 14 percent bigger and 30 percent brighter than average, making it a supermoon. This month’s full Moon on Monday 14 November is the closest Moon to Earth since 26 January 1948. The Moon won’t be this super again until 25 November 2034!
Science teams from across the United States have submitted 28 proposals for missions to explore the moons of Jupiter and Saturn, touch the asteroid-like satellites orbiting Mars, visit unseen worlds and hunt for objects that could strike Earth one day.
