Night Sky Notes – June 2016

Night sky notes for June 2016         Geoff Mitchell

The June night sky shows the summer constellations rising mid evening, the summer solstice on June 20th marks he shortest night   The bright planet Jupiter in the constellation of Leo is now low in the southwest by early evening and the Red Planet Mars is seen low in the south in the constellation of Scorpius with the ringed planet Saturn at opposition in early June visible low in the southeast. Currently its rings are nicely open, showing the North Polar Region.

The summer night sky contains many fine objects to view for the enthusiast in the midnight hours but also has a few notable events of special interest.   During June look to the NW some 90 to 120 minutes after sunset or to the NE 90 minutes similarly before sunrise. This when the Sun is just below the horizon during the summer months , under favourable conditions  extremely high clouds at 80 km altitude known as Noctilucent Cloud (NLC) may be seen. NLC’s show a bluish colour and also show filamentary structure.

In the south west the constellation of Virgo as twilight fades contains a large cluster of Galaxies, the Virgo Super cluster, the light twilight conditions, even on moonless evenings makes these faint misty patches a challenge in moderate sized telescopes. Our own Milky Way galaxy stretches from the constellation of Auriga [The Charioteer], marked by the bright star Capella through the constellations of Perseus and Cassiopeia all now positioned low in the north. In the east however the summer constellations of Cygnus [The Swan or Northern Cross] now rises by late evening. The bright star Vega in the adjacent constellation of Lyra [The Lyre] is seen in the north east and Altair in the constellation of Aquila low in the east by late evening. Vega, Altair and Deneb, in the constellation of Cygnus form the `Summer Triangle` asterism, a useful sign post for the summer skies. Look with binoculars along the central axis of Cygnus , down through Aquila into the south and see the rich star fields of Scutum and Sagittarius , with the famous `Teapot ` asterism,  low in the south in the early morning hours in June and late evening in July.

Adjacent to  Lyra the familiar `keystone asterism ` of the constellation  Hercules is noted for the Globular clusters  M13 and M92 the former containing some 750,000 stars, a nice view in a small telescope .

Scorpius [The Scorpion] in part is visible low in the south as twilight fades. Use binoculars to see the myriad of stars in these rich star clouds, best seen on clear dark moonless evenings from darker locations outside the town or remember to take your binoculars with you if you’re on your holidays. The red star Antares, as the name means `rival to Mars ` currently this can be compared with the planet Mars  which appears to move retrograde  to the stars in Scorpius into Libra  and still shining brightly (magnitude -1.6m) post opposition. The low elevation of Mars as seen from the UK makes observing detail on Mars more difficult. Mars continues to be centre of attention for planetary observers early evening in June.

Look low in the SE late evening to find a yellowish star to the east of Mars. The yellow star is in fact the ringed planet Saturn which reaches opposition in early June in the constellation of Ophiuchus [The Serpent Bearer].  Although rather low as seen from the UK in June, modest telescopes give a classic view of this gem of the solar system and will show the rings and the brightest moon Titan. Larger telescopes show up to six or so fainter moons and any white oval features on the planets disk and some of the ring detail such as Cassini Division etc.  Observe the Seeliger Effect around opposition to mid and note any brightening of the ring system due to the ring particles angle of illumination changing causing the apparent brightening.  Also in the constellation of Ophiuchus, periodic comet 252P / Linear is a fading binocular / telescopic  object [magnitude 7m] visible late evening low in the south, the bright twilight skies makes this a difficult object, perhaps more suited to imaging than visual observation on moonless evening.

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

High in the east the bright orange star Arcturus in the constellation of Bootes [The Herdsman] is the brightest star in the northern hemisphere of the sky.  Between Arcturus and the Keystone asterism in Hercules lies the `U` shaped constellation of Corona Borealis [Northern Crown].

Planets in June 2016

Mercury is poorly placed in dawn skies in June, reaching greatest elongation on June 5th .

Venus is in our daytime skies with Superior Conjunction on June 6th– Venus will be an evening object in late 2016

Mars is just past opposition, visible mid evening shining bright orange at magnitude -2m (See notes)

Jupiter is now slipping into evening twilight but it is still a good view telescopically

Saturn now at opposition (June 3rd) rises by mid evening in Ophiuchus low in south. Although it is low in our June skies but has the ring system open at 26 degrees – a classic view of this `gem ` of the solar system.

Uranus is not visible in daytime skies – best views in autumn skies.

Neptune is not visible in daytime skies – best seen in autumn skies

Moons phases in June

New Moon         June 5th                 Moonless, best time for deep sky and Milky Way observing.

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

Full Moon            June 20th              Best days to see bright ray craters like Copernicus / Tycho.

Last Quarter      June 27th              Moon visible in daytime skies.  Do not look directly at the Sun.

Meteor showers        Ophiuchids – peak June 10th to June 20th – low rates – rather unfavourable.                                                                        June Lyrids, peak June 16th – unfavourable

The highlights of the month

Mars just past opposition low in UK skies, mid evening – unmistakable orange in colour and bright (-2m).

Saturn at opposition  low in south east by late evening  , rings open at 26° DE [tilt] showing Saturn’s North Pole.

Saturn, Mars and blood red star Antares make an easily recognised triangle in the late evening sky

Noctilucent cloud – from late May watch the NW skies 2 hours after sunset (see text)

Moon and Jupiter conjunction, June 11th ,  Moon and Mars, June 16th and Moon and Saturn June 18th.

Waxing  crescent Moon visibility    June 5th moonset  is 21:22 BST is within  6 minutes of sunset  at 21:16  , so the earliest possible crescent Moon is not readily visible just after sunset  on June 5th. Caution.  Do NOT look at the Sun directly with or without optical aid. However a nice 4% waxing crescent moon is visible after sunset from around 21:30 BST until moon set 22:23 BST on June 6th. Note the dimly lit part visible by Earthshine is readily seen with binoculars or small telescope.  Only look for the crescent Moon after the sun has completely set.

Mars reached opposition on May 22nd and for most of June the planet continues to show some of the dark features such as Syrtis Major shown, visible in moderate sized telescopes. Note due to the rotation period of Mars, the dark feature visibility for evening observing will depend on the date of observation. Small telescopes show the white polar cap.

Saturn visible low in the SE late evening, reaches opposition in early June the planet shows nice ring detail and northern polar region. Titan is the brightest of Saturn’s moons which is visible in a small telescope and moves from evening to evening with respect to the planet, orbiting Saturn in just 15.9 days.

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  Artificial satellite and International Space Station visible passes and bright Iridium flares – check the  home page for posting s of details of favourable observing times.

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