By April 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).
Lording over this month’s night sky is the giant planet Jupiter. It will be at its closest point to Earth on the 7th April. Visible all night long in the constellation of Virgo. It shines far brighter than any star with a magnitude of –2.3. Using a small telescope or Binoculars you will be able to observe its four biggest moons.
After sunset, look low in the west for Mercury. It will be setting two hours after the Sun. It will be at its greatest eastern elongation on the 1stof the month, with a magnitude of 0.0, but fades rapidly as the month progresses.
Mars is on the move from Aries to Taurus passing near the Pleiades on the 21st of the month. The red planet shines at magnitude +1.5 and sets around 11pm.
Saturn rises around 1am, in Sagittarius, at magnitude +0.4.
Venus rises on hours before the Sun at magnitude –4.3
Both Uranus and Neptune are lost in the glare of the sun, and are unfavourable for observation.
Comets
Get your binoculars to check out not one but two comets this month.
Comet P41 Tuttle-Giacobini-Kresak will be faint with a magnitude of +7.0; the celestial wanderer is flying high in the sky between Ursa Major and Ursa Minor. It will be moving towards the head of Draco.
Towards the end of the month it is joined by Comet C/2015v2 (Johnson). Another binocular object, also at magnitude +7.0. It will be located in Hercules.
Meteor Showers
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). Meteors are tiny grains of dust left over from comets that travel around the Sun. This meteor shower is the remains of comet Thatcher 1861.
Phases of the Moon for April
First Quarter 3rd
Full Moon 11th
Last Quarter 19th
New Moon 26th