All information presented here is taken from my book Nightscenes 2021 (pt1)


There will be no printed edition for 2021 but a pdf/kindle version for January to June 2021 is now available from the nightscenes web page.

Click on the monthly image to get a larger high resolution view of the night sky set for 53° N (Horncastle, England) but is usable for the UK and Eire.  All charts are set for the 1st of the month at 22:00 GMT (10pm) and can be used on the other dates and times shown in each corner of the chart.


April 2021
































































Solar System quick summary


Some charts & images in the text can also be clicked to give a larger view.


Uranus slips down into the evening twilight and is lost to view from mid month. Mars is the main planet for the month easily visible in the evenings and passes close to M35 on the 26th & 27th.  Minor Planet Vesta is also well placed for evening viewing using binoculars all month. Venus and Neptune are still in the solar glare so not observable but in the last days of April Mercury creeps into the bright evening twilight. Meanwhile Saturn and Jupiter lie in the morning twilight but are becoming easier to spot. The moon occults mag 3 Theta Oph on the 30th in the early morning. The April Lyrids Meteor shower peak during the day on the 22nd but may be spoiled by moonlight later that night.



Main events


Mars! For the time being it continues to dominate the evening skies and April is no exception. On the 2nd it lies above the open star cluster NGC 1746, a nice view  in binoculars and a good photo opp for those into astrophotography. Mars moves on and by the 13th it lies almost on a line between the two horns of Taurus the Bull with El Nath above and Zeta Tauri below. The waxing crescent moon joins in and on the 16th it lies to the far right of Mars,  just under the star cluster, then on the 17th the moon lies to the left of Mars, note the moon is to the correct scale for this chart. The positions for those two dates for Mars are also shown on the chart. Mars moves along passing into Gemini from Taurus (~ 23rd) then moves past the bright open cluster M35 on the 26th and 27th. On April 30th it forms a triangle with the stars Tejat and Propus, Mu and Eta Geminorum.


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The top chart is set as an equatorial format but now let’s take a different, more realistic view and add in the moon for the previous two days. At left we see the sky as we would standing outside looking roughly west in a wider field of view. The path of Mars for April is shown but Mars is now only marked for the beginning and end of the month plus the four days the moon passes through the view.

This region of sky is quickly dropping down into the encroaching evening twilight. The crescent moon lies below the Pleiades, M45 star cluster on the 14th then lies between the Pleiades and the Hyades/ Aldebaran on the 15th. It then moves up past Mars as mentioned in the first section. Both charts are set for 9pm BST.







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Staying with the evening sky and switching to the last week of the month we find the innermost two planets trying to creep up into the bright evening twilight. Venus and Mercury are very low down but are close together from April 25th to 27th as shown here set for ~ 8:45pm. Venus is the brighter of the two at mag -3.9 compared with Mercury at mag  -1.6 so you won’t get them confused. Look to the WNW half an hour after sunset but you will need to be quick as they set rapidly after that. Mercury puts on its best evening apparition next month and this is its start.



On the 2nd of April in the morning sky we find our moon lies above left of the bright orange star Antares in Scorpius. Next morning the waning moon lies close to the border of Ophiuchus and Sagittarius. But once again as this is at the start of the month then it repeats at the end and so there are four moons shown at correct scale on the chart with the moon lying almost between Graffias and Antares on April 29th then on the 30th very close to Theta Ophiuchi.


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So close that in fact the moon occults the star which is naked eye at mag 3.2. Disappearance is on the bright limb and as times vary slightly across the UK/Ireland, begin looking from about  2:20am until the star vanishes.

Reappearance will be sudden on the dark limb as the star is technically a pinpoint of light. Again, begin watching early at around 3:20am. There is a second fainter star that is also occulted, Hip 84947 at mag 6.3 so if you have a telescope look out for that too. Two occultations for the price of one!


In the morning sky early in the month we find the waning crescent moon lies below right of Saturn on the 6th then next morning it lies really low and close to the horizon below right of Jupiter. Look for them low in the SE about 30 to 40 minutes before sunrise and the moon is shown at the correct scale. On the 8th Jupiter lies due north of Delta Capricorni helping to identify the star below the planet. Saturn lies to the right of Theta Capricorni.



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The April Lyrids meteor shower peaks on the 22nd in the early afternoon and unfortunately the Moon is above the horizon later all night so will spoil the view. However it is always worth keeping an eye out and looking away from the direction of the moon to view the ‘darkest’ part of the sky. The radiant lies in the NE sky and rises higher during the night at around 60° high by 3am so this is an early morning shower to look out for. Note, the chart above shows the radiant moves slowly towards Lyra and slightly below Vega from Hercules from April 15th to 25th. It is perhaps a little ironic that most of the time the radiant actually lies in Hercules since the formalisation and adoption of the IAU constellation boundaries!




Also look out for the following:


 4th  Last Quarter moon lies close to Nunki, Sigma Sagittarii (morning)

13th  Crescent moon lies to left of Uranus (evening twilight)

18th  Moon lies to upper left of Mebsuta, Epsilon Geminorum (evening)

19th  Moon lies to the left of Pollux and close to Kappa Geminorum (evening)

20th  First Quarter moon lies in Cancer above Beehive cluster (evening)

22nd Moon lies to right of Sickle asterism and Regulus (evening)

25th  Moon lies to right of Porrima in Virgo (morning) / Moon lies above Spica in

the evening



Clear skies, happy sky watching and stay safe!



Paul







Webmaster  © Paul L Money 2021


The UK & Ireland Night Sky for 2020

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