Night Sky Notes – April 2019

Night sky notes for April 2019             Geoff Mitchell

The April night sky now  shows the spring constellations but with daylight saving time (BST) and the Sun moving north of the celestial equator , twilight skies mean later observing hours as we head into the summer months. The spring night sky contains many fine objects to view with both binocular and small telescopes and this month has a few notable events of special interest. The bright planet Jupiter is rises low in the east by late evening. The red planet Mars is visible in the western twilight below the Seven Sisters star cluster (M45) in early  April.

Galaxy hunting season is now `open` the constellations of Leo and Virgo contain a number of Galaxies. The brighter member galaxies of the Virgo Super cluster are visible as small, faint misty patches in moderate sized telescopes on moonless clear evenings from a dark observing site.  Use the star Vindemiatrix as a starting point, to view the chain of brighter galaxies including M87 which are visible as tiny `smudges`.

Our own Milky Way galaxy  stretches from the constellation of  Auriga , marked by the bright star Capella overhead  through the constellations of  Perseus  and Cassiopeia and down into the north west . This faint band of stars is best seen on clear dark moonless evenings from darker locations outside the town.

The familiar asterism of the plough in the constellation of Ursa Major, The Great Bear is seen high in the north east with its handle or tail pointing towards the horizon mid evening. Use the right hand pair of stars Dubhe and Merak ( Use the pointers) to find the faint pole star Polaris and the position of North.

The spring constellation of Leo rises early evening, the brightest star Regulus and the `reversed question mark ` shaped star asterism of `The Sickle` makes this an easily recognisable constellation. Leo stretches eastward and is marked at the tail end by the star Denebola.  Leo contains some moderately bright galaxy pairs visible in moderate sized telescopes on moonless evenings.  M65/M66 and NGC 3628 form the famous galaxy triplet, all three galaxies being visible in the same telescopic field of view.

The galaxy rich constellations of Virgo and Coma Berenices can now be seen rising by mid evening and well placed due south by late evening . Some of the brighter galaxies may be seen as faint misty patches telescopically. Markarian’s chain of galaxies stretching from the bright star Vindemiatrix towards the star Denebola in Leo, contains the brighter galaxies M59, M60, M86 and M87 (See notes).

Low in the north east Lyra is the radiant for the April Lyrids meteor shower  from mid April (maxima April 22nd ), best seen in the early hours but with a rather low zenith hourly rate (ZHR) of just 18 meteors per hour. Full Moon on April 19th [Good Friday] means moonlight interferes. Lyra heralds the approach of summer skies.

The orange star Arcturus in the constellation of Bootes [ The Herdsman]  is the brightest star ( north of the celestial equator ) . Bootes shaped rather like a `Kite` is easily recognisable in the spring night sky rising in the east by late evening.  Also in the north east aspect is the constellation of Hercules  of which the four stars forming the `Keystone ` asterism  are easily spotted . About 1/3 down the right hand side of the `keystone `  M13 a beautiful globular cluster can be seen telescopically – the cluster of stars may contain up to 750,000 stars in total  . Above the keystone M92 is another globular cluster , almost rivalling M13 telescopically.

Two Asteroids reach opposition in early April , Asteroid No 2 Pallas  is located in the constellation Bootes and at 7.9m magnitude is a binocular object – a star like point moving night to night against the background stars- seen notes.  Asteroid No 7 Iris  is fainter and a real challenge to find in the obscure constellation of Corvus [The Crow].

 

Mercury returns low in dawn skies –poorly placed – Greatest elongation (W) 27.7° April 11th

Venus is low in dawn skies brilliant at -4.0m, telescopically phase increasing to 88% by month end.

Mars, low in early evening, close to Pleiades Apr 1st – but shrinks 4.1” apparent diam fading to + 1.7m

Jupiter is low in dawn skies in Ophiuchus during Apr, shining brightly at -2.2m

Saturn is low in dawn twilight in Sagittarius – poorly placed in April .

Uranus is low in twilight evening skies in Pisces

Neptune – best seen in autumn.

Meteor showers –    April Lyrids      range Apr 14th / 30th  maxima Apr 22nd  ZHR 15/ hour – Unfavourable

Eta Aquarids   range Apr 19th /May 28th , maxima May 6th /7th  ZHR 40/hour – Low in UK skies

 

Planets in April 2019

Mercury is at greatest elongation 27.3° on April 11th (dawn) – poorly placed in UK skies.

Venus is place very low in the east at dawn – difficult to see in bright twilight. Phase increases to 88% in April.

Mars is visible in evening skies in the west and is found just below the `Seven Sisters` star cluster in Taurus.

Jupiter is an early morning object in the constellation Ophiuchus , rising by midnight in late April.

Saturn is low in pre dawn skies in the constellation of Sagittarius  and is just 0.4° north of the Moon on April 25th

Uranus is poorly placed in evening twilight – best views in autumn skies.

Neptune is at conjunction in April and  placed in our daytime skies – best seen in autumn skies

Moons phases in April

New Moon         April 5th                 Moonless, best time for deep sky observing and comet observing.

First Quarter     April 12th             Best days to see shadow details in lunar craters (early evening)

Full Moon            April 19th             Best days to see bright ray craters like Copernicus / Tycho.

Last Quarter      April 26th              Moon visible in daytime skies.  Do not look directly at the Sun.

Meteor shower s                            April Lyrids, rather low rates, best in early morning April 18th to 25th Unfavourable

The highlights of the month..

April skies, Milky Way visible high overhead on moonless evenings in darker skies.

Double cluster, on the Perseus / Cassiopeia border high overhead, nice pair of star clusters.

Pleiades (Seven Sister’s) star cluster (M45) with Mars and Hyades cluster in Taurus with the Moon (April 9th)

Beehive cluster (M44) visible to the unaided eye but best seen with binoculars.

Telescopic triplet of galaxies M65/M66/NGC3628 in the constellation of Leo

Virgo cluster of Galaxies, brighter members of the cluster can be seen with small telescopes or binoculars.

International Dark Skies Week 2019 March 31st to April 7th – Refer to LAS website home page for details.

2.2% waxing crescent Moon is visible low in the west after sunset , Earthshine faintly illuminates (April 6th)

More detailed sky notes and LAS Newsletters, Finder charts are available to LAS members via the Members` page on the LAS Website www.lutonastrolink.org.uk

Current LAS newsletters

No 213   Observing prospects for Iridium satellite flares (March / April)

No 214   Observing Asteroid 2 Pallas at Opposition (7.8m Binocular) in early April 2019

No 215   Observing Asteroid 7 Iris at Opposition (9.4m Telescopic) in early April 2019

 

 

 

Sky looking south at 10pm British Summer Time (BST), early April 2019

 

Gemini is placed high in the south west with Castor leading Pollux across the sky. To the south  the constellation of Leo noted by the bright star Regulus and the `Sickle` asterism of stars and outstretched body resembles a crouching lion , with the star Denebola at the tail end. Between Pollux and Regulus, binoculars show the nice `Beehive` star cluster in the constellation of Cancer.

Telescopes show galaxies such as the three edge on spiral M65, M66 and NGC 3628 the famous Leo Triplet.

The Virgo cluster has many faint galaxies , the brightest member galaxies can be seen as faint `smudges` using binoculars from a dark observing site on clear moonless evenings.

 

 

Sky looking east at 10pm BST early April 2019

The spring constellations now appear in the eastern sky by mid evening. The orange star Arcturus is found by following the curve of stars in the handle of the Plough down. The constellation of Bootes, resembles a `kite` or `Club ` in shape.   The star Izar is a beautiful orange/ blue double star visible in small telescopes. To the east of Bootes find the `horseshoe` shaped constellation of Corona Borealis (Northern Crown) and the `Keystone` Asterism in the constellation of Hercules. Hercules also has M13 the famous Globular Cluster, visible to the unaided eye as a misty patch; telescopes show the true wonder of this cluster with over 750,000 stars. Likewise another nice globular is M92 in Hercules.

The bright white star Spica in the constellation of Virgo is easily found. Virgo has the super cluster of Galaxies, some of the brighter member galaxies can be seen as misty patches or ovals using modest telescopes. Finder charts see notes, more detailed finder charts are available on the LAS Member’s page (LAS Newsletter No 144) .

 

 

 

 

 

Sky looking north at 10pm BST early April 2019

 

The Plough stands on its handle follow the pointer’s Dubhe and Merek to find the polestar Polaris

The `W` shaped constellation of Cassiopeia is found on the opposite side of the polestar to the Plough. Low in the northeast the bright star Vega in the constellation of Lyra skirts the horizon, rising by early              morning.  Lyra is associated with the radiant of the April Lyrids meteor shower. Rates of these meteors,    derived from Comet C/1861 Thatcher are rather low, range April 16th to 25th.(unfavourable due to      moonlight interfering )

 

Sky looking west at 10pm BST early April 2019

 

Mars moves eastward and is located just below the `Seven Sister`s ` star cluster (M45, Pleiades) in early April.

 

 

 

 

Highlights of the month

Virgo cluster of Galaxies. located in `the bowl ` of Virgo between bright stars Vindemiatrix  in Virgo and Denebola in Leo , the brightest member galaxies shown are bright enough to see as faint misty patches with a small telescope or binoculars .  Virgo is a `Y` shaped constellation with the bright white star Spica at the base.

LAS map showing the brighter galaxy members of the Virgo Cluster located along Markarian’s Chain

Asteroid No 2 Pallas, binocular s required to see this star like point` located in the constellation of Bootes

move night to night against the background stars