The April night sky
I think we are in for a real treat this month. We have the biggest full moon of the year, on the 8th; the planet Venus at its most brilliant and a display of shooting stars.
April also sees the seasonal change from winter constellations to spring constellations is more or less complete.
The Plough is practically overhead, with the ‘W’ of Cassiopeia is at its lowest. The stars Vega and Deneb, which form two thirds of the summer triangle, are rising in the northeast although they have yet to become prominent.
The main spring stars can now easily be found. In the south is the constellation Leo (the Lion), which looks like a giant backwards question mark, and at its base is the bright star Regulus. To find Regulus use the two pointers in the plough and rather than drawing a line to the North Star, go in the opposite direction.
The plough can also help us find two other bright stars in the spring sky. Using the handle of the Plough draw a curve round and down. This line will reach the bright orange star Arcturus in the constellation of Bootes (the Herdsman). If the line is continued further it will reach the bright blue-white star Spica in the constellation of Virgo (the Virgin).
Venus is at its most spectacular this month. The evening star reaches its maximum brilliance of magnitude –4.5, on 28th April, and stays above the horizon until 030am. Through a low power telescope, you will see Venus grow steadily larger as it approaches the Earth, while its shape changes from half-lit to a crescent.
On 3rd of the month, Venus passes in front of the Pleiades star cluster. The evening star is so bright that to the unaided eye it may just look as though Venus has gone fuzzy; but binoculars or a low power telescope will reveal the glory of Venus accompanied by a swarm of stars.
The other three planets visible this month are all rising just before dawn breaks.
The brightest is Jupiter, shining at magnitude –2.2 in the constellation of Sagittarius. The gas giant rises above the horizon about 3am.
Half an hour later, Saturn at magnitude +0.6 rises in the constellation of Capricornus.
At the start of the month Mars lies just below Saturn. The red planet rises at the same time. It is slightly fainter at magnitude +0.8 than Saturn. During the course of April the red planet moves to the left of Saturn, growing brighter, to finish the month a little more brilliant than Saturn at magnitude +0.4.
Mercury, Uranus and Neptune, are to close to the Sun for observation.
The first major meteor shower since January can be seen this month. The April Lyrids occur on the night of April 21st/22nd when about 10 meteors per hour can be seen. This should be a good opportunity to see them, as the Moon will be well out of the way. The Lyrids are so named because they appear to come from the constellation of Lyra (the Lyre). The meteors are tiny grains of dust left over from comet Thatcher 1861, as they burn up in the Earths atmosphere.
Phases of the Moon for April:-
First Quarter 1st April
Full Moon 8th April
Last Quarter 14th April
New Moon 23rd April