Starwatch

What to expect in the night sky


To many people, May spells potential doom because of the multi-planet alignments which occur this month and which are mistakenly believed to trigger off massive earthquakes. The first alignment, involving five planets, occurs on May 3 and 4, when the line-up will also include the Sun and the Moon. Unfortunately, the planets are all very close to the Sun, set soon after sunset and will be very difficult to observe. The second planetary alignment occurs on May 17 when the Moon is absent from the line-up but the five bright planets and the Sun are clustered within a span of 19°. Again, close proximity to the Sun, which is in the middle of the span, will make planetary observation very difficult. Venus, Jupiter and Saturn are below the horizon at sunset and Mars and Mercury will only be visible through binoculars.

As the Earth spins on its journey around the Sun during May and June, look out for the tiny planet Mercury, which has often not been seen by visitors from northern latitudes. It climbs steadily higher above the horizon in the evening sky during May and should be clearly visible above the sea from a westward-pointing beach. It is just above a crescent Moon on June 3. A spectacular conjunction of Jupiter and Saturn will occur close to the horizon in the pre-dawn sky on May 28, when some streaking Eta Aquarid meteors may enhance the beauty of this planetary pairing.

May and June are the best months for a comprehensive view of the Caribbean sky. The Southern Cross, the first constellation many star-minded visitors ask about since it is invisible north of latitude 35° in the United States and also below the horizon in Canada and Europe, crosses the Meridian at about 9 p.m. in early May. It is pinpointed by two bright, slanting stars, Alpha and Beta Centauri in the constellation Centaurus, The Centaur; this grouping distinguishes it from the “false cross” in the neighbouring constellation Argo, The Ship. Argo, now divided into the smaller constellations Vela, The Sails, Puppis, The Poop and Carina, The Keel, begins to set below the western horizon soon after sunset. An interesting dark region in the Southern Cross called the “Coal Sack”, visible on a really dark night with the naked eye, was once thought to be an opening into the awful solitude of empty space. Radio astronomy has revealed that it is a cloud of gas which hides the stars behind it.

One of the more glorious southern constellations, Scorpius, The Scorpion, with its red eye, the star Antares, is invisible from Britain, the northern United States and Canada, but is unmistakable to the north-west of the Southern Cross where it is followed by the rather dim stars of the constellation Sagittarius, The Archer. The brighter stars of Sagittarius trace out the shape of a teapot which appears to be pouring water on the Scorpion’s tail. This is a highly interesting region of the sky for those with binoculars, as a short sweeping of the area between Sagittarius and Scorpius will reveal a number of star clusters and nebulae. Look for the circlet of stars which traces out the constellation Corona Australis, The Southern Crown, just below Sagittarius.

The faint stars of the constellation Libra, The Scales, lie between Scorpius and a crooked square of stars which traces out the small constellation Corvus, The Crow. The bright star Spica, in the constellation, Virgo, The Virgin, shines above Corvus. It is the end of a curve which leads the eye through the orange star Arcturus, in the kite-shaped constellation of Bootes, the Herdsman, to the tail of Ursa Major, The Big Bear (also called The Big Dipper), which is found straddling the meridian during May and June. Just as visitors from the north delight in identifying the Southern Cross, so visitors from Australia look for The Big Dipper, which is invisible in southern latitudes. If you pride yourself on your 20/20 vision, see if you can pick out the two stars of the “optical double” star Mizar in the handle of the Big Dipper. Mizar has a companion star called Alcor; the Arabs called the pair of stars “the horseman and rider”.

Other bright stars are found in the northern sky during May and June. Bright Regulus in the constellation, Leo, The Lion, sets in the west as Vega, the brightest star in the small constellation Lyra, The Lyre, rises in the east. The long sprawl of the constellation Draco, The Dragon, curves between Ursa Major and Ursa Minor, The Little Bear (or The Little Dipper) which is rarely above the Caribbean horizon in its entirety.

The star maps for 11 p.m. on May 9 and 9 p.m. on June 9 were drawn for Trinidad, but they may be applied to the entire region from Trinidad to Jamaica.