We are now in the month of April and the spring equinox is behind us. The clocks have gone forward and the Sun now sets at 20.00 at that start of the month. This still gives loads of time to get out and observe but also means we can enjoy longer evenings.
The last two months have been very poor in terms of naked eye objects with most of any planets visible in the early morning sky. This doesn’t really change this month but there will be plenty of early morning conjunctions to reward one for getting up early.
The spring constellations are now prominent in the sky so now is a good time to familiarise yourself with them. The best time to look will be around the middle of the month when the Moon is new.
Sun and Moon
|Date||Sunrise (Irish Time)||Sunset (Irish Time)|
Mercury is not visible in the very early days of April. Look for it in the west after 8th April in the evening sky. It will set 30 mins after the Sun on 8th. Make sure the Sun has set before looking for it. Mercury will improve over the course of the month. By the end of April, Mercury will set about 1 hour 40 mins after sunset.
Venus is a morning planet in April. It never rises very high, rising about 1.5 hours after the Sun in the south east. On the morning of 27th look for the crescent Moon below Jupiter and Venus.
Mars is also visible in the morning sky before sunrise but it wont be easy to spot. Try using Venus as a signpost. Mars will be just to the left of Venus.
Jupiter will not be seen in the first part of the month. It rises about 20 mins before the Sun at the start of the month. At the end of April it will be seen close to Venus in the pre dawn sky. Look low in the southeast before sunrise.
Saturn appears low in the Southeast before sunrise during April. Towards the middle of the month Venus, Saturn and Mars will form a line in the southeast.
Stars and Constellations
The above sky chart, from heavens-above.com is for 23:00 on 15/04/2021. You can click on the chart to open a new tab and bring you to Heavens Above. On this website you can generate a custom chart for the time and date you wish. The winter constellations are fading in the west to be replaced by the spring constellations.
In the west after sunset is the constellation of Gemini (the twins), Auriga (the charioteer) and Perseus. To the northwest are Cepheus (the house), Cassiopeia (the queen), Andromeda and Pegasus (the flying horse). Andromeda is the location of the Andromeda galaxy which is the furthest object that can be seen with the naked eye. Although, you will need very dark skies to see it. Andromeda and the Milky Way galaxy are headed for a collision and will collide in an estimated 4.5 billion years.
Over in the southwest have the spring constellations. You will see Leo (the lion) and the plough is now rising higher in the sky. Taking the curve of the handle of the plough and following it toward the eastern horizon will bring you to a bright red star called Aldebaran. This is the brightest star in the constellation of Bootes. Although this constellation represents a herdsman it actually looks more like a kite. It’s always nice to see this constellation appearing. It will be high in the sky in the summer and is a sign that we are heading out of winter and into spring. Finally, to the east of Bootes is the constellation of Hercules. You can identify this by its distinctive “Keystone” shape. To the north is Lyra (the harp) and Cygnus (the swan).