Depending on where you live in the British Isles, you may be fortunate to view a lunar occultation of naked-eye double star delta (δ) Geminorum at dawn on Tuesday, 27 August 2019. Observers fortunate enough to lie on the so-called graze line will see the star appear to flicker on and off as the mountains and valleys of the northern lunar polar regions drift by.
If you’re bemoaning the current dearth of bright planets in the evening sky, or light pollution prevents you from viewing a multitude of spring galaxies, don’t give up – there are always attractively coloured double and multiple stars to view. Join us on a tour of the Northern Hemisphere constellation of Boötes (pronounced Bo-oh-tees), the Herdsman, easily located due to its brightest star, Arcturus.
Skywatchers in the UK and Western Europe should look low to the south-southeast an hour before sunrise on 31 January to see a beautiful naked-eye conjunction of Venus, the old crescent Moon and Jupiter, all within a span of 8½ degrees. But if you have a telescope and live in just the right place, you can also see the Moon hide a double star.
Now that the season of mists and mellow fruitfulness is upon us and the bright summer stars and planets are slipping away to the west, why not seek out some of the spectacular double stars of the autumn sky? We show you how to find some celestial gems suitable for small to medium telescopes in the constellations of Aquarius, Aries and Andromeda.
Skywatchers in Western Europe looking at the rising 13-day-old gibbous Moon in the south-southeast at dusk on Sunday, 27 May can also see prime-time Jupiter within the same binocular field of view. But look closer in the vicinity of the solar system’s largest planet and you’ll see an easily resolved double star – alpha Librae.
A waxing crescent Moon hanging low above the horizon in evening twilight is always a pleasant sight to behold, but observers in the UK watching the 4-day-old Moon through a telescope around 40 minutes after sunset on Sunday, 24 September have an additional treat in store in the form of an occultation of naked-eye star gamma (γ) Librae.
Jupiter now lies highest in the UK sky at sunset, but the Solar System’s largest planet and its four bright Galilean moons still provide plenty of observable events during June, as we reveal. If you’re uncertain which evening ‘star’ is Jupiter, the Moon conveniently passes by on the night of 3—4 June, a time when European skywatchers can also see the Moon occult (hide) bright double star Porrima.
At the beginning of August, keen observers in the heart of the UK can celebrate the return of truly dark skies around 1am BST. But the naked-eye stars are out by 11pm, and if you cast your gaze two-thirds of the way from southeast horizon to overhead at this time you can see the so-called Summer Triangle in all its glory. Here’s our guide to some of the celestial highlights therein.