Saturday, April 18, 2014 The Moon is above Antares. Look southwest an hour before sunrise.
This Month's Sky Map

Sky Map for April 2014

Sky Map for April 2014

This Sky Map is representative of the sky as seen from London, UK at Latitude N 51° 31' 12.00", Longitude W 0° 6' 0.00" on the 15th of April 2014. The map is suitable for latitudes up to 15° north or south of London.

The map is how the sky appears directly over your head. This is why the East and West cardinal points appear reversed. Hold the map above your head for an accurate representation of the night sky. The Sky Map is how the sky looks at the 1st of the month at 23:30 BST (British Standard Time), the 15th at 23:00 BST and on the last day of the month at 22:00 BST.

o - indicates nebulae and star clusters
Ecliptic - is the apparent path of the Sun across the sky

THE NIGHT SKY FOR APRIL 2014

Ian Morison from the Jodrell Bank Centre for Astrophysics tells us what can be seen in the night sky this month.

Northern Hemisphere

Ian Morison tells us what we can see in the northern hemisphere night sky during April 2014.

The constellation of Gemini and the planet Jupiter are setting in the west as the Sun goes down. Leo, with its bright star Regulus, is in the south, and to the left of Regulus are the galaxies M95, M96, M66 and M65, which are visible in binoculars or a small telescope. To the left of Leo, more such objects can be found in a region between Coma Berenices and Virgo known as the Realm of the Galaxies, which looks towards the Virgo Cluster. The bright star Arcturus is to the south-east, in Bootes, with the circlet of stars called Corona Borealis to its left. The bright star Vega rises in the north-east later in the evening, in Lyra, followed by Cygnus and the Milky Way. Ursa Major is almost overhead, containing the famous asterism of the Plough, or Big Dipper. If you look diagonally up the trapezium-shaped part of the Plough from bottom-left to top-right, and then carry on for the same distance again, you reach the galaxies of M82 and M81. M82, nicknamed the Cigar Galaxy, is a starburst galaxy where many new stars and supernovae can be seen. The middle star of the Plough's handle is actually a double, with two components called Mizar and Alcor, or the Horse and Rider. A telescope shows that Mizar is itself a double star, and another, reddish star appears in the same field of view.

The Planets

  • Jupiter is a little past the best of its current apparition, but is still high in the sky just after nightfall, shining at magnitude -2.2 at the beginning of the month. Its angular size reduces from 38 to 35" during April, but you can still see the Galilean moons and, when the seeing is good, the Great Red Spot at certain times.
  • Saturn is coming to the best of its apparition, rising at 22:30 UT (Universal Time) at the start of the month and 20:30 UT at its end. It has a magnitude of about +0.1 and moves retrograde through Libra, its angular diameter increasing from 18.2 to 18.6" during April. Its rings are now at 22 degrees to the line of sight and span 40" across, allowing a small telescope to pick out the Cassini Division in good seeing conditions. Unfortunately, Saturn does not currently rise very high in the sky for northern hemisphere observers.
  • Mars is in Virgo and reaches opposition (opposite the Sun in the sky) on the 8th, so it is visible throughout the night and reaches its highest point in the sky at about 02:00 BST (British Summer Time, 1 hour ahead of Universal Time) at the start of the month and 23:00 BST at the end. Mars is at its brightest, around magnitude -1.5, in the second week of April, and comes closest to Earth in its current orbit on the 14th, when it is just over 15" in angular diameter. The surface is about 91 percent illuminated, and features can be seen with a small telescope. The planet moves retrograde and approaches the bright star Porrima.
  • Mercury is just visible above the eastern horizon before sunrise at the beginning of the month, but is then lost as it passes superior conjunction (behind the Sun in the sky) on the 26th.
  • Venus rises before morning twilight as April begins and can be spotted at magnitude -4.4, but its is below 10 degrees' elevation at sunrise. Its brightness drops to -4.2 as it gets closer to the Sun in the sky during the month, and it shrinks from 22 to 17" across even as its illuminated fraction goes up from 54 to 66 percent.

Highlights

  • Jupiter is still prominent in the sky this month. Its surface features have changed over the last few years, with the South Equatorial Belt disappearing and reappearing again.
  • The large asteroids Vesta, at magnitude +5.8, and Ceres, at magnitude +7, reach opposition on the 13th and 15th respectively. They are only 2.5 degrees apart all month, allowing them to be seen together in binoculars, and lie up and left of the bright star Spica in Virgo. The best time to spot them is towards the beginning or end of April, when the Moon is not in the way.
  • Mars is less than 5 degrees from the nearly-full Moon after sunset on the 14th, in the south-east, with Spica only 4 degrees away on the other side of the Moon.
  • Venus is just 6 degrees from a thin, waning crescent Moon before dawn on the 26th, rising in the east.
  • The great lunar craters of Tycho and Copernicus can be observed, as always, around the time of full Moon, which occurs on the 15th of this month.
  • If you have a large radio polarimetric bolometer array to hand, why not try to observe the effect of gravitiational waves on the cosmic microwave background at any time and in any part of the sky? All you have to do is clear away the foregrounds that make up the rest of the Universe first.

Southern Hemisphere

John Field from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during April 2014.

The daylight hours continue to shorten as the southern hemisphere progresses through early autumn. Three bright planets can be seen in the early evening sky: Jupiter in the north-west, in Gemini, Mars in the north-east, shining with an orange-red hue near to the star Spica in Virgo, and Saturn, which follows Mars in Libra. Mars makes the closest approach to Earth in its current orbit this month, while Saturn's rings and its largest moon, the orange-coloured Titan, are well placed for viewing with a telescope. Mars and Saturn are high in the sky by midnight and above Mars is a kite-shaped quartet of stars in the constellation of Corvus the Crow. Delta Corvi is a wide double star, but there are few other easily-observed objects in the vicinity. Nearby is Hydra the Water Snake, a long path of stars with a distinct group of five stars forming its head.

The winter constellation of Scorpius rises in the east in the evening. Its brightest star, at magnitude +1, is the red supergiant Antares, known as the Rival of Mars because of its colour. It is called Rehua by Maori in Aoteroa (New Zealand), and marks the eye of Maui's fishing hook. This hook is called Te Matau a Maui, for which the back and stinger of the Scorpion's body become the curve and tip of the hook. According to Maori mythology, the great hero Maui used this hook to pull the North Island of New Zealand from the ocean, for which that part of the country is named Te Ika-a-Maui - the Fish of Maui. The tip of the hook crosses a wide and bright part of the Milky Way, and in this part of the sky we are looking towards the Galactic centre, some 30,000 light-years away. The Southern Cross of Crux and its pointer stars are found by running up the Milky Way, as are the Diamond and False Crosses. Crux is called Te Punga in Maori star lore. The hero Tamarereti sailed across the heavens in his Waka, or canoe, placing the stars into the sky, and Te Punga was his boat's Anchor. You can find south halfway between Crux and the bright star Achernar, in Eridanus, by following the line from the top to the base of the Cross. Two-thirds of the way along this line are the Magellanic Clouds, dwarf satellite galaxies of the Milky Way.

Highlights

  • Venus and Mercury are both visible low in the east before dawn in the first week of April.
  • New Zealand and eastern Australia are treated to a total lunar eclipse as the Moon rises at sunset on the 15th, while central and western Australia see a partial phase of the eclipse.
  • Australia witnesses a partial solar eclipse in the late afternoon of the 29th.
Compiled by Ian Morison