Northern Hemisphere

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

Leo is setting in the west as it gets dark, while in the south is Bootes, with its bright star Arcturus. Rising in the east is the Summer Triangle, consisting of the stars Vega in Lyra, Deneb in Cygnus and Altair in Aquila. A third of the way from Altair towards Vega is the asterism of Brocchi's Cluster, or the Coathanger, in front of the Cygnus Rift. Delphinus the Dolphin lies below it. Ursa Major is high in the north-west and contains the famous asterism of the Plough, with the stars Merak and Dubhe pointing towards Polaris, the North Star. In the middle of the Plough's handle is a double star, known as Mizar and Alcor, and Mizar itself can be seen to be a double star through a telescope.

The Planets

• Jupiter sets nearly three hours after sunset at the beginning of June. It fades from magnitude -1.9 to -1.8 during the month, and shrinks from 33 to 32" in angular diameter. By month's end, it is low down at sunset and lies almost on the line between the stars Castor and Pollux. The Galilean moons are still visible using a small telescope, but surface details on the planet are harder to spot due to atmospheric scintillation.
• Saturn lies in Libra, between the stars Spica and Antares. It dims from magnitude +0.2 to +0.4 during the month and is about 18" across. It is moving retrograde (westward) across the sky towards the double star Alpha Librae, lying 2.5 degrees away from it at the end of June. Saturn's rings are about 40" across and are inclined at 21 degrees to the line of sight, making the major divisions between the rings visible to small telescopes, but viewing is slightly hampered by the planet's low elevation.
• Mercury can be observed low in the west-north-west shortly after sunset at the beginning of the month, but it fades from magnitude +1.2 to +3.4 by the 11th and is lost in inferior conjunction (between the Earth and the Sun) by the 19th.
• Mars Is receding rapidly, dimming from -0.5 to 0 in magnitude and shrinking from 11.8 to 9.5" in angular size during June. It starts the month 2.5 degrees from the star Porrima and ends it 3.5 degrees from Spica, moving through the constellation of Virgo. Mars is at its highest at sunset, giving the last chance of the current apparition to observe features on its surface.
• Venus starts the month shining at magnitude -3.9, moving quickly through the lower part of Aries. It then enters Taurus and passes between the Hyades and Pleiades star clusters on the 28th, ending the month 3.5 degrees from the star Aldebaran. The planet is low on the eastern horizon just before dawn, showing a gibbous phase and decreasing from 14 to 12" in size during June. Over the same period, its fractional illumination increases from 77 to 85 percent, keeping its brightness almost constant.

Highlights

• Saturn is well placed for observation this month. It is at its height soon after dark. To find it, follow the Plough's handle down past red Arcturus to white Spica. Saturn is the yellowish object to Spica's lower left. A magnitude 8.2, Titan - Saturn's largest moon - can be seen. A larger telescope shows the distinction between the planet's A, B and C rings.
• This month is a good time to observe the globular cluster M13 in Hercules and the 'double double' star in Lyra. Hercules is between the bright stars Arcturus and Vega, and its four brightest stars make a trapezium called the Keystone. M13 is two-thirds of the way up its right-hand side, and is the brightest globular cluster in the northern hemisphere sky. The double double, Epsilon Lyrae, is to the left of Vega, showing two stars in binoculars but four when viewed through a telescope.
• Noctilucent clouds may be spotted towards the end of June. They are the highest clouds in the atmosphere at around 80 kilometres above the Earth, and can be seen towards the north during late twilight. Normally too faint to see, sunlight shining from below the northern horizon can render them visible around midsummer, just when the lower part of the atmosphere goes into shadow. Noctilucent clouds seem to be getting bigger, brighter and more common, but their cause is unclear.
• Jupiter can be seen lying just below the star Pollux an hour after sunset from the 2nd to the 4th, low in the west-north-west. Mercury may also be visible, very low beneath Pollux's twin star, Castor.
• Mars is 3 degrees above and slightly left of a waxing gibbous Moon an hour after sunset on the 7th.
• Saturn is about 2 degrees up and to the right of a waxing gibbous Moon after sunset on the 10th, low in the east-south-east.
• Venus is 2.5 degrees to the left of a thin crescent Moon before dawn on the 24th, sitting between the Hyades and Pleiades Clusters.

Southern Hemisphere

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

Jupiter is visible in the west after sunset for the first half of the month, before disappearing into the twilight. Sirius, the brightest night-time star, is can be seen in the same part of the sky in the evening, and again in the south-east before dawn. The zodiacal constellations of Scorpius and Sagittarius dominate the south-eastern sky in the evening, the red star Antares - meaning 'Rival of Mars' - marking the Scorpion's heart. To Maori and some Polynesian cultures, Scorpius is a fishing hook and Antares is the eye of the hook, stained with the blood of the mythical hero Maui. Binoculars or a telescope show many star clusters and nebulae in this region of the sky. The globular clusters M4 and NGC 6144 appear close to Antares, while a number of double stars can be seen along the body of the Scorpion with the unaided eye. The open cluster NGC 6231 is near the Scorpion's stinger, as is M7, and both can be seen as hazy glows with the naked eye under a dark sky. M6, the Butterfly Cluster, is not far away, a telescope revealing an elongated cluster of stars forming its wings. The constellation of Sagittarius the Archer is also rich in objects. Its brightest stars are known as the Teapot, near the top of which is the bright globular cluster M22.

Two of the most spectacular night sky sights are M8, the Lagoon Nebula, and M20, the Trifid Nebula. M8 is a compact cluster surrounded by a halo of nebulosity containing a dark rift, and is dominated on its western side by two sixth-magnitude stars. M20 is nebulous, with the dark lanes that split it into three sections discernible using a telescope of 200 millimetres or more in aperture. Its pink and blue colours can be seen in long-exposure photographs. It is also worth finding M23, an open cluster containing arcs and chains of stars, M24, a bright cloud of stars interspersed with dark nebulae, M25, an open cluster hosting several deep yellow stars, and M55, an open cluster of magnitude 7.4.

The Milky Way is at its brightest, widest and deepest around Scorpius and Sagittarius. It is Al Nahr (the River) to Arabs, the River of Heaven to Chinese and Te Ikaroa (the Long Fish) to Maori. The centre of the Milky Way galaxy is in the direction of Sagittarius, and its dark lanes are dust and gas that may one day form new stars. A scan along it, towards Crux and Carina in the west, reveals more star clusters and glowing clouds of gas. The Magellanic Clouds can be seen low in the south on a moonless night, and are small galaxies not far outside our own.

The planet Saturn is towards the north in the evening, in front of the stars of Libra, and Mars can be seen in a nearby part of the sky. Saturn is fading and shrinking as it recedes from us, but a small telescope can still pick out the disc of the planet, as well as its rings and its largest moon, Titan. Venus rises around 05:00 NZST (New Zealand Standard Time, 12 hours ahead of Universal Time) at the beginning of the month and around 06:00 by the end, appearing as a brilliant morning star. Venus is directly above Matariki (the Pleiades star cluster) in mid-June. The heliacal (dawn) rising of Matariki and Puanga (the star Rigel) on the 21st marks the winter solstice, when the Sun rises and sets at its most northerly points, and is the start of the new year for Maori in Aotearoa (New Zealand).