Night Sky Watch for April

Written by David Pugh

Well we are now into Spring and the clocks have gone forward. During April Mars is still the only naked eye evening planet and is part of the highlight of the month. (More on that shortly). Closer to home, the International Space Station blazes across the evening sky at around 9pm until April 3rd.

Neither Mercury nor Venus will be visible during April. However, our nearest neighbour the Moon is involved in several events this month. At dusk on April 14th a very thin (7% lit) crescent Moon lies 8 degrees below the Pleiades and on the following evening a 13% lit crescent Moon lies between the Pleiades and Hyades clusters. If it is clear this should make a lovely view and it should be possible to photograph all three as the Moon will not be too bright. Even on April 16th the crescent Moon east of the Hyades will still make an attractive view. Then, at dawn on April 27th there will be a Full "Pink" Moon, the second of 4 Super Moons in 2021. The name "Pink" Moon is simply the name given to a Full Moon in April, the time when pink Phlox flower. So the Moon will not actually look pink but it will appear fractionally larger, as a "Super Moon" than a normal Full Moon.

Now for the red planet. At dusk on April 17th Mars, in NE Taurus, will be only 3.1 degrees below the crescent Moon and, at mag +1.5, will be easily visible if it is clear. However, if you would like a real challenge, around noon (from 11am to 1pm) that same day, which is a Saturday, Mars will be extremely close to the Moon, only 0.6 degrees to the NE i.e one Moon diameter away. Although this will obviously be in daylight, the Moon as a 24% lit crescent should be easily visible if it is clear. Once you have found the Moon the trick then is to point a telescope at the Moon and sweep to the NE to N to find Mars. In daylight, if it is clear, it will only appear as a faint star but this is one of those very rare events when you have an opportunity to find the red planet in daylight! Good luck! If anyone manages this please let me know..

Early risers might catch their first glimpse of Jupiter and Saturn in Capricornus low down above the SE horizon as morning planets when the crescent Moon is near them on April 6th and 7th. Uranus and Neptune are both in conjunction with the Sun and so will not be visible in April. Comet C/2020 R4 Atlas was discovered on Sept 12 2020 at mag 19.7. Since then it has gradually been getting brighter and is predicted to reach mag 9 in April but could get brighter. It moves from Aquila on April 4, through Northern Ophiuchus on the 14th, southern Hercules on the 19th, Corona Borealis on the 24th and northern Bootes on the 29th. It passes closest to us (42 million miles) on 23 April when it should be at its brightest. Might be worth a look as the brightness of comets is notoriously difficult to predict. (Apparently Comet C/2021 A1 Leonard may put on a good show but we will have to wait until December for that).

The April Lyrid meteor shower should peak on the nights of April 21/22 and 22/23 but will be blighted to a degree by strong glare from the Moon. The shower's radiant near Vega clears the eastern horizon by late evening but the normal peak view of about 10 meteors per hour will be suppressed by moonlight, although they are known to offer the odd fireball.

Ursa Major (the Plough) and Leo remain well placed for observation so continue to refer to last month's Night Sky Watch for deep sky objects in those constellations. Virgo is also more prominent now in the southern sky with loads of galaxies to view as this is the heart of the Virgo supercluster of galaxies. To find Virgo follow the tail stars of the Plough downwards in a curve, first through brilliant Arcturus in the constellation Bootes and onwards down to Spica the principal star of Virgo. If you then find Denebola (Beta Leonis) the easternmost second magnitude star in Leo and, with a telescope at low powers, sweep eastwards into the "Bowl of Virgo", you will come upon the heart of the Virgo galaxy cluster, what is known as "Markarian's Chain", a curved line of galaxies including giant elliptical galaxies M84 and M86 as fuzzy mag 9 oval patches. Further south, close to the border with Corvus the Crow you could also try for the famous Sombrero galaxy M104 at mag 8 but fairly small, only 7 x 3' across. Good Hunting!