The Evening Sky in September 2015

Download a PDF containing this chart, additional charts for specific areas of the sky and descriptions of interesting objects visible at this time of year.

The Evening Sky in September 2015

Mercury and Saturn are bright planets in the evening sky. At the beginning of the month Mercury is making its best evening sky appearance of the year, low in the west. Cream-coloured Saturn is northwest of the zenith at dusk and midway down the western sky by late evening. Mercury and Saturn are similar in brightness to orange Arcturus on the northwest skyline. Above Saturn is orange Antares. Crux, the Southern Cross, and the Pointers are midway down the southwest sky. Canopus, the brightest star in the sky, skims along the southern skyline. It is matched on the northern skyline by Vega, one of the brightest northern stars. The Milky Way spans the sky from northeast to southwest.

Mercury makes its best evening sky appearance of the year at the beginning of the month, setting more than two hours after the sun. It slips down the sky night to night, setting earlier, then disappears as it passes between us and the sun at the end of the month. The crescent moon will be below and right of Mercury on the 15th. Above Mercury is Spica, the brightest star in Virgo. Mercury is small in a telescope. It looks like a tiny first-quarter moon at the beginning of September, waning to a taller crescent as it comes closer. Mercury is one-third of Earth's diameter. It is 116 million km away mid-month.

Saturn, being distant, moves little against the background stars. It stays by the Scorpion's claws through the month as the region sinks lower in the west. Saturn is worth a look in any telescope. Even binoculars will show it as an oval, the planet and rings blended together. It is 1550 million km away mid-month.

The Milky Way spans the sky from north to south. Many of the brightest stars are scattered along it or near it. Two exceptions are Canopus, near the south skyline, and Arcturus, setting early in the northwest. Both stars are shining through a lot of air which makes them twinkle colourfully. Canopus, being white, shows all colours like a diamond. Orange Arcturus twinkles red and green. Canopus is a truly bright star: 13 000 times the sun's brightness and 300 light years* away. On the opposite horizon is Vega, the second-brightest northern star after Arcturus. It is due north at dusk and sets in the late evening. Vega is 52 times brighter than the sun and 25 light years away.

Midway down the southwest sky are 'The Pointers ', Beta and Alpha Centauri. They point down to Crux the Southern Cross. Alpha Centauri is the third brightest star. It is also the closest of the naked eye stars, 4.3 light years away. Beta Centauri, along with most of the stars in Crux, is a blue-giant star hundreds of light years away.

West of overhead, above Saturn, is orange Antares. It marks the heart of the Scorpion. The Scorpion's tail hooks toward the zenith like a back-to-front question mark, the 'fish-hook of Maui' in Maori star lore. Antares is a red giant star: 600 light years away and 19 000 times brighter than the sun. Above Scorpius is 'the teapot' made by the brightest stars of Sagittarius. It is upside down in our southern hemisphere view.

The Milky Way is brightest and broadest overhead in Scorpius and Sagittarius. In a dark sky it can be traced down past the Pointers and Crux into the south. To the north it passes Altair, meeting the skyline right of Vega. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 30 000 light years away, is in Sagittarius. The actual centre is hidden by dust clouds in space. The nearer clouds appear as gaps and slots in the Milky Way.

The Large and Small Clouds of Magellan, LMC and SMC, look like two misty patches of light in the south sky. They are easily seen by eye on a dark moonless night. They are galaxies like our Milky Way but much smaller. The LMC is about 160 000 light years away; the SMC about 200 000 light years away.

Brilliant Venus (not shown) is the 'morning star'. It rises in the east two hours before the sun. A telescope shows it as a thin crescent. Earth-sized Venus is 60 million km away mid-month.

*A light year (l.y.) is the distance that light travels in one year: nearly 10 million million km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes sunlight four years to reach the nearest star, Alpha Centauri.

Newsletter editor:

Alan Gilmore Phone: 03 680 6817
P.O. Box 57 Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Lake Tekapo 7945
New Zealand

The Solar System in August 2015

Dates and times are NZST (UT + 12 hours) unless otherwise specified. Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

Sunrise, sunset and twilight times in August

                     August  1  NZST                 August 31  NZST
                    morning  evening                 morning  evening
            rise:   7.27am,  set:  5.27pm    rise:   6.46am,  set:  5.57pm
Twilights
  Civil:    starts: 7.00am,  ends: 5.55pm    starts: 6.21am,  ends: 6.23pm
  Nautical: starts: 6.27am,  ends: 6.28pm    starts: 5.49am,  ends: 6.55pm 
  Astro:    starts: 5.54am,  ends: 7.01pm    starts: 5.17am,  ends: 7.22pm

August PHASES OF THE MOON (times as shown by GUIDE)

  Last quarter:  August  7 at  2.03 pm (02:03 UT)
  New moon:      August 15 at  2.53 am (Aug 14, 14:53 UT)
  First quarter: August 23 at  7.31 am (Aug 22, 19:31 UT) 
  Full moon:     August 30 at  6.35 am (Aug 29, 18:35 UT)

The planets in August

Both Venus and Jupiter are at conjunction with the Sun during August, marking their return to the morning sky. Mercury will become well placed for evening viewing during the month. Mars moves up a little in the pre-dawn sky. Saturn, in the evening sky, will set before midnight.

Mercury will set some 40 minutes after the Sun on August 1 making it a very difficult object to see despite its -1.1 magnitude. On the evening of the 7th Mercury, Jupiter and the star Regulus will form a cluster in the western sky. Mercury will be half a degree to the lower right of Jupiter which itself will be a degree below Regulus. The group will be very low in the sky before it is dark enough to see them.

As a marker Venus will be about 7.5° to the left of the group only slightly higher than Regulus. Obviously finding Venus will be a guide. Binoculars will help show the other objects.

As the month progresses, Mercury will set increasingly later than the Sun, by the 16th 95 minutes later and on the 31st a good two and a quarter hours later. At the end of nautical twilight the planet at magnitude 0.2 will be 15° up and slightly to the north of west making it an easy visual object. Around this date will provide the best opportunity of the year to see the elusive innermost planet.

Mercury stars the month in Leo crossing into Virgo on the 23rd.

Venus, unlike Mercury, will be heading back towards the Sun. It sets 2 hours after the Sun on August 1, so will be readily visible for a while after sunset. The distance between the planet and the Sun will decrease over the next couple of weeks until Venus is at inferior conjunction between the Sun and Earth on the morning of the 16th (NZST).

At this conjunction Venus will pass the Sun at an angular distance of 7.5° south of the Sun as seen from the Earth. Also as seen from the Earth the planet will be barely 1% lit, yet despite that it will be at magnitude -3.9.

As a result of its southerly elongation it may be visible at conjunction shortly before sunrise on the morning of the 16th. That morning Venus will rise at 6.33 am, the Sun 35 minutes later. So the planet should be in view very low a little to the north of east. The time of conjunction is about 7 am

By August 31, Venus will rise into the morning sky more than 90 minutes before the Sun so will readily be visible before sunrise some way round towards the northeast.

Jupiter is also heading towards the Sun during August. Although it starts the month closer to the Sun than Venus, the faster moving inner planet overtakes the gas giant and get there first. Jupiter is at conjunction on the 27th (NZST). It will of course be beyond the Sun as seen from the Earth passing less than a degree south of the Sun. No hope of seeing Jupiter at conjunction!

At conjunction the planet will be 806 million km (5.388 AU) beyond the Sun and 957 million km (6.398 AU) from the Earth. After conjunction Jupiter becomes a morning object but with only 4 days of the month to go will not be visible.

On the other hand at the beginning of August Jupiter will set nearly 100 minutes after the Sun, so is likely to be briefly visible for the first few evenings of August with Venus a few degrees to its upper left. On the evening of the 11th, Jupiter will be less than half a degree from Regulus, but the two will be only 11.5° from the Sun so very difficult to see.

Saturn is very much an evening object in August, but only as an early evening object by the end of the month. It sets just after midnight on the 1st, and before 10.30 pm on the 31st. The planet will be in Libra moving slowly to the east towards beta Scorpii in the head of Scorpius.

On the evening of August 22, the moon will be some 6° degrees below Saturn. The moon will be nearly half lit, just before first quarter.

Mars will slowly move a little further up into the morning sky before sunrise . It rises 40 minutes earlier than the Sun on the 1st, just over an hour earlier on the 31st. But it will remain low in the dawn sky and at magnitude 1.8 very difficult to see in the twilight. The planet starts August in Gemini but crosses into Cancer on August 6.

Outer planets

Uranus is in Pisces all August. It rises around 11.20 pm on the 1st and 2 hours earlier on the 31st. The planet will be at magnitude 5.8 so readily seen in binoculars. The 67% lit moon will be 3° from Uranus on the night of 5/6 August.

Neptune rises just before 8 pm on August 1 with its rise time advancing to just before 6 pm on the 31st. The planet remains in Aquarius at magnitude 7.8, so is quite easily seen in binoculars. The moon passes Neptune twice in August. The first occasion is on the night of August 2/3, the second at the time of full moon on the 30th.

Pluto continues to be in Sagittarius all August with a magnitude 14.3.

Brighter asteroids:

(1) Ceres is in Sagittarius during August fading a little from magnitude 7.6 to 8.2 following its opposition late July. During August the asteroid moves further into Sagittarius; by the end of the month it will be between the kite shaped asterism containing omega Sgr and the wide pair of stars theta 1 and 2 Sgr.

(4) Vesta is in Cetus throughout August brightening from magnitude 7.2 to 6.7. The asteroid rises at 10.25 pm on the 1st and 8.20 pm on the 31st. It is stationary mid month.

(9) Metis starts the month at magnitude 10.0 but brightens to 9.2 by the 31st. The asteroid is in Aquarius about 11° from Neptune at the end of August.

(15) Eunomia starts August in Pisces at magnitude 9.7, rising at 11.10 pm. It is well north of the equator and moving further north. On the 25th it swings into Andromeda. By the end of August it will rise at 9.30 pm and be at magnitude 8.5, only slight fainter than Ceres.

Brian Loader  
New Zealand

The Evening Sky in August 2015

Download a PDF containing this chart, additional charts for specific areas of the sky and descriptions of interesting objects visible at this time of year.

The Evening Sky in August 2015

At the beginning of the month three bright planets appear low in the western evening sky soon after sunset.

Brilliant silvery Venus is brightest and highest. Golden Jupiter is below and right of Venus. Mercury is well below the two bright planets on August 1st. It moves quickly up the sky, night to night, as Venus and Jupiter sink lower. On the 7th Mercury is just a full-moon's width to the right of Jupiter. Venus is left of the close pair of planets. All three set about 70 minutes after the sun. Mercury continues its ascent of the evening sky through August while Venus and Jupiter disappear in the twilight. By the 31st Mercury is setting due west after 8 pm, making its best evening sky appearance of the year. At month's end the bright orange star Arcturus is setting in the northwest, well to the right of Mercury, often flashing red and green as it goes. Mercury is a small and unimpressive planet in a telescope. It is one-third Earth's diameter and 180 million km away mid-month.

Cream-coloured Saturn is the only bright planet in the late-evening sky. It is just north of overhead. Orange Antares is in the same area of sky but fainter than Saturn and closer to the zenith. Well down the northwest sky is orange Arcturus, mentioned above. Low in the north is white Vega, making a brief appearance in our sky. Exactly opposite Vega, low in the south, is Canopus twinkling colourfully. In the southwest are 'The Pointers', Beta and Alpha Centauri with Crux, the Southern Cross, below them.

A small telescope shows Saturn's ring system and biggest moon, Titan, looking like a star about four ring-diameters from the planet. The moon appears near Saturn on the 22nd.

Antares marks the heart of the Scorpion. The Scorpion's tail hooks around the zenith like a back-to-front question mark. Antares and the tail make the 'fish-hook of Maui' in Maori star lore. Antares is a red giant star: 600 light years* away and 19 000 times brighter than the sun. It is a relatively cool 3000 C, hence its red-hot colour. Below or right of the Scorpion's tail is 'the teapot' made by the brightest stars of Sagittarius. It is upside down in our southern hemisphere view.

Midway down the southwest sky are 'The Pointers ', Beta and Alpha Centauri. They point down and rightward to Crux the Southern Cross. Alpha Centauri is the third brightest star and the closest of the naked eye stars, 4.3 light years away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away and thousands of times brighter than the sun.

Canopus, the second brightest star, is near the south skyline at dusk. It swings upward into the southeast sky through the morning hours. Canopus is truly bright: 13,000 times brighter than the sun and 310 light years away. On the opposite horizon is Vega, one of the brightest northern stars. It is due north in mid-evening and sets around midnight. Vega is 52 times brighter than the sun and 25 light years away.

The Milky Way is brightest and broadest overhead in Scorpius and Sagittarius. In a dark sky it can be traced down past the Pointers and Crux into the southwest. To the northeast it passes Altair, meeting the skyline right of Vega. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 30 000 light years away, is in Sagittarius. The actual centre is hidden by dust clouds in space. At the very centre is a black hole four million times the sun's mass. Dust clouds near us appear as gaps and slots in the Milky Way. Binoculars show many clusters of stars and some glowing gas clouds in the Milky Way.

The Large and Small Clouds of Magellan LMC and SMC look like two misty patches of light low in the south, easily seen by eye on a dark moonless night. They are galaxies like our Milky Way but much smaller. The LMC is about 160 000 light years away; the SMC about 200 000 light years away.

After passing between us and the sun mid-month, Venus appears in the eastern dawn twilight. By the 20th it is rising in the east an hour before the sun. Venus remains the 'morning star' for the rest of the year.

*A light year (l.y.) is the distance that light travels in one year: nearly 10 million million km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes four years for sunlight to reach the nearest star, Alpha Centauri.

Newsletter editor:

Alan Gilmore Phone: 03 680 6817
P.O. Box 57 Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Lake Tekapo 7945
New Zealand

The Solar System in July 2015

Dates and times are NZST (UT + 12 hours) unless otherwise specified. Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

The Earth is at aphelion on July 7 at about 4 am. It will then be 1.0167 AU, 152 million km from the Sun.

Sunrise, sunset and twilight times in July

                       July  1  NZST                July 30  NZST
                    morning  evening                 morning  evening
            rise:   7.45am,  set:  5.04pm    rise:   7.28am,  set:  5.26pm
Twilights
  Civil:    starts: 7.16am,  ends: 5.33pm    starts: 7.01am,  ends: 5.54pm
  Nautical: starts: 6.42am,  ends: 6.08pm    starts: 6.28am,  ends: 6.27pm 
  Astro:    starts: 6.08am,  ends: 6.41pm    starts: 5.55am,  ends: 7.00pm

July PHASES OF THE MOON (times as shown by GUIDE)

  Full moon:     July  2 at  2.20 pm (02:20 UT)
  Last quarter:  July  9 at  8.24 am (June  8, 20:24 UT)
  New moon:      July 16 at  1.24 pm (01:24 UT)
  First quarter: July 24 at  4.04 pm (04:04 UT) 
  Full moon:     July 31 at 10.43 pm (10:43 UT)

The planets in July

Venus and Jupiter will be a spectacular pair the first few evenings of July, closest on the 1st, gradually separating during the rest of the month. Mercury may be briefly visible in the morning before sunrise early in July, and possibly just visible in the evening at the end of July.

Saturn is easily visible all evening, setting well after midnight. Mars remain too close to the Sun for observation.

Mercury may be briefly visible in the morning sky shortly before sunrise early in the month. On the morning of the 1st, 45 minutes before sunrise the planet will a low 8° above the horizon in a direction a little east of northeast. The planet's magnitude will be -0.1. A week later Mercury will be half a magnitude brighter, but less than 5° up at the same time.

The planet closes in on the Sun until it is at superior conjunction on the morning of July 24. At conjunction its angular distance from the Sun as seen from the Earth will be about 1.5°. It will actually be 200 million km from the Earth, 48 million km beyond the Sun.

After conjunction Mercury will become an evening object. By the end of July it will set just over half an hour after the Sun. On the 31st the planet will be very low almost directly below Venus. Its magnitude will be -1.2, but it is not likely to be visible in the bright twilit sky.

Mercury starts July in Taurus, it enters Gemini on the 9th and moves on into Cancer on the 23rd.

Venus and JUPITER start July as a close pair just under 20 arc-minutes apart (two-thirds the diameter of the full moon) on the 1st. Venus will, of course, be much brighter than Jupiter. The spectacular conjunction is likely to be a little subdued due to the full moon but the latter will be on the opposite side of the evening sky to the pair of planets.

Both planets spend the month in Leo. In the evenings following their conjunction Jupiter will rapidly fall behind and get lower than Venus. At first Venus will look to be moving towards Regulus but will turn away from the star, being stationary on the 23rd. Jupiter will move much more slowly but steadily towards the star. It will be August before they are at their closest.

On the July 18 the moon as a very thin crescent will be just over 6° to the left of and slightly lower than Jupiter. The following evening will find the moon close to Venus with the two about 1.6° apart. Regulus will be about 3° from them.

On the 19th the moon will occult Venus, an event visible in daylight from Queensland. The path of the occultation passes to the north of New Zealand.

Mars will be a nominal morning object during July. On the 1st it rises only 6 minutes before the Sun. So the planet will be far too close to the Sun to see. Things are little better at the end of July. Mars will then rise about 45 minutes before the Sun, but be so low in the morning twilight that at magnitude 1.7 it will not be visible.

Saturn will be well placed in the evening sky throughout July. It will be moving slowly to the west in Libra, not moving very close to any bright stars. It is joined by the 71% lit, gibbous moon on the 26th. The latter will be about 2.5° to the lower right of Saturn mid evening.

Saturn's north pole will be tilted 24° towards the Earth so that the ring system is well open for viewing.

Titan, Saturn's largest moon, at magnitude 8.6, should be visible as a faint object in binoculars given a dark sky. It is best observed when Titan is at is greatest distance from Saturn, about 3 arc-minutes. Its greatest elongations to the east (left) of the planet are on the July 3 and 18, to the west (right) of Saturn on July 11 and 26. On the first and last dates moonlight may make Titan difficult to see in binoculars. July 3 is only a day beyond full moon, on the 26th our moon is close to Saturn.

Outer planets

Uranus is in Pisces all July. It rises shortly after midnight on the 1st and some 90 minutes before midnight of the 31st. With a 5.8 magnitude it is readily seen in binoculars. The planet is stationary on the morning of July 27 after which it will start moving in a retrograde sense to the west.

Neptune rises just before 10 pm on July 1 with its rise time advancing to just before 8 pm on the 31st. The planet remains in Aquarius at magnitude 7.9 to 7.8, so is quite easily seen in binoculars.

Pluto is in Sagittarius all July and at opposition on the 6th. It will then be nearly 32 astronomical units from the Earth and near 33 from the Sun with a magnitude 14.3.

Brighter asteroids: (to do)

(1) Ceres is in Microscopium much of July, but moves into Sagittarius in the 25th. It rises an hour and a half after sunset on the 1st and nearly as much before sunset on the 31st. It does not pass close to any bright stars during the month. The asteroid is at opposition on July 25 and brightens to magnitude 7.5 for a few nights near that date.

(4) Vesta is essentially a morning object in Cetus throughout July. It rises just after midnight on the 1st and at 10.30 on the 31st. Its magnitude brightens from 7.6 to 7.2 during the month.

(15) Eunomia starts July on the border of Pegasus and Pisces at magnitude 9.7. The asteroid rises half an hour after midnight on the 1st and at 11.15pm on the 31st.It is in Pisces for the rest of the month within a few degrees of the magnitude 2.8 star gamma Peg. At their closest on the 14 the two are 1.5° apart. By July 31 Eunomia will have brightened to magnitude 9.1

Brian Loader  
New Zealand

The Evening Sky in July 2015

Download a PDF containing this chart, additional charts for specific areas of the sky and descriptions of interesting objects visible at this time of year.

The Evening Sky in July 2015

Brilliant silver Venus and golden Jupiter are close together in the west at the beginning of July and remain an eye-catching pair through the month. Northeast of the zenith is Saturn, cream-coloured. Well left of Saturn, at the same elevation but fainter, is Spica. Midway down the north sky is orange Arcturus, similar in brightness to Saturn. Sirius, the brightest true star, sets in the southwest as twilight ends, twinkling like a diamond. Canopus, the second brightest star, is also in the southwest at dusk. It swings south later. South of the zenith are 'The Pointers', Beta and Alpha Centauri. They point to Crux the Southern Cross on their right. To the right of Saturn is orange Antares, the brightest star in Scorpius. Vega rises in the northeast around 9 pm.

Venus and Jupiter are less than a full-moon's width apart on July 1. This is a rare close pairing of bright planets. They set in the west around 8:30 pm. Through July Jupiter sinks lower in the twilight as we move to the far side of the sun from it. Venus also falls lower, but remains above Jupiter. Venus is catching up on the Earth. It passes between us and the sun in mid-August. The two planets appear similar in size in a telescope. Venus is a tall thin crescent. Jupiter is a disk with its four 'Galilean' moons in a line on either side. The planets' apparent pairing is strictly a line-of-sight effect. On July 15 Venus is 62 million km from us and Jupiter is 930 million km. In mid-July Venus is just left of Regulus, the brightest star in Leo. The moon is near the two planets on the 18th and 19th.

Saturn is always worth a look in any telescope. A small telescope shows the ring system and biggest moon Titan looking like a star about four ring-diameters from the planet. Big telescopes show fainter moons closer in. Saturn is around 1400 million km away in July. It sets in the southeast around 3 a.m.

.

Alpha Centauri is the third brightest star. It is also the closest of the naked eye stars, 4.3 light years* away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away. Canopus swings down to the southern skyline before midnight then moves into the southeast sky in the morning hours. It is a 'circumpolar star': it never sets. Crux and the Pointers are also circumpolar. Canopus is a truly bright star: 13 000 times the sun's brightness and 300 light years away.

Arcturus, in the north, is the fourth brightest star and the brightest in the northern hemisphere sky. It is 120 times the sun's brightness and 37 light years away. It twinkles red and green when setting in the northwest around midnight. It is an orange colour because it is cooler than the sun; around 4000°C.

East of the zenith, and right of Saturn, is the orange star Antares, marking the heart of the Scorpion. The Scorpion's tail, upside down, is stretched out to the right of Antares making the 'fish-hook of Maui' in Maori star lore. Antares is a red giant star: 600 light years away and 19 000 times brighter than the sun. Below Scorpius is 'the teapot' made by the brightest stars of Sagittarius. It is also upside down in our southern hemisphere view.

The Milky Way is brightest and broadest in the east toward Scorpius and Sagittarius. In a dark sky it can be traced up past the Pointers and Crux, fading toward Sirius. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 30 000 light years away, is in Sagittarius. The actual centre is hidden by dust clouds in space. A scan along the Milky Way with binoculars shows many clusters of stars and some glowing gas clouds.

The Large and Small Clouds of Magellan, LMC and SMC, look like two misty patches of light low in the southern sky. They are easily seen by eye on a dark moonless night. They are galaxies like our Milky Way, but much smaller. The Large Cloud is 160 000 light years away and 5% of the mass of the Milky Way. The Small Cloud is 200 000 light years and 3% of the Milky Way's mass.

Mercury ends a morning sky appearance. At the beginning of July it is below orange Aldebaran in the northeast as twilight begins. It sinks lower in the dawn and disappears mid-month.

*A light year (l.y.) is the distance that light travels in one year: nearly 10 million million km or 1013 km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes four years to reach the nearest star, Alpha Centauri.

Newsletter editor:

Alan Gilmore Phone: 03 680 6817
P.O. Box 57 Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Lake Tekapo 7945
New Zealand

The Evening Sky in June 2015

Download a PDF containing this chart, additional charts for specific areas of the sky and descriptions of interesting objects visible at this time of year.

The Evening Sky in June 2015

Venus, brilliant and silver, and golden Jupiter appear in the northwest quarter of the sky after sunset. Venus sets soon after 8 pm at the beginning of the month. Jupiter sets two hours later. Through the month Venus moves a little higher in the evening sky while Jupiter sinks lower. This brings them together. By the end of June they are only a full-moon's width apart. The thin crescent moon will be near them on the 20th. Though low, Jupiter is worth viewing in a telescope. Even binoculars will show one or two of its moons looking like stars close to the planet. Venus looks like a featureless first-quarter moon, similar in size to Jupiter. The close separation of the planets is a line-of-sight effect. At the end of the month, when the two planets appear close together Venus is 78 million km away and Jupiter is 910 million km away on the far side of the Sun.

Low in the west at dusk is Sirius, the brightest true star. It sets around 9 pm mid-month, twinkling like a diamond. Canopus, the second brightest star, is in the southwest. It is a 'circumpolar' star: one that never sets. Sirius appears bright both because it is 20 times brighter than the sun, and because it is relatively close at nine light years*. Canopus, the second brightest star, is higher in the southwest sky, circling lower into the south later on. Canopus is 310 light years away and 13,000 times brighter than the sun.

Arcturus is a lone bright star in the northeast. Its orange light often twinkles red and green when it is low in the sky. It sets in the northwest in the morning hours.

Saturn, midway up the eastern sky, is the same brightness as Arcturus but cream-coloured. To its right but fainter, is orange Antares, the brightest star in Scorpius. A small telescope shows Saturn's rings and its biggest moon, Titan, about four ring-diameters from the planet. Other smaller moons appear as faint stars closer to Saturn. Saturn is 1350 million km away mid-month.

Crux, the Southern Cross, is south of the zenith. Beside it and brighter are Beta and Alpha Centauri, often called 'The Pointers' because they point at Crux. Alpha Centauri is the closest naked-eye star, 4.3 light years away. Beta Centauri and many of the stars in Crux are hot, extremely bright blue-giant stars hundreds of light years away. They are members of a group of stars that formed together then scattered. The group is called the Scorpio-Centaurus Association.

Antares, marking the scorpion's heart, is a red giant star: 600 light years away and 19 000 times brighter than the sun. Red giants are much bigger than the sun but much cooler, hence the orange- red colour. Though hundreds of times bigger than the Sun, Antares is only about 20 times the Sun's mass or weight. Most of the star's mass is in its hot dense core. The rest of the star is thin gas. Red giants are dying stars, wringing the last of the thermo-nuclear energy from their cores. Antares will end in a spectacular supernova explosion in a few million years. Below Scorpius is Sagittarius, its brighter stars making 'the teapot'.

The Milky Way is brightest and broadest in the southeast toward Scorpius and Sagittarius. It remains bright but narrower through Crux and Carina then fades in the western sky. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 30 000 light years away, is in Sagittarius. A scan along the Milky Way with binoculars will find many clusters of stars and some glowing gas clouds. Relatively nearby dark clouds of dust and gas dim the light of distant stars in the Milky Way. This makes them look like holes and slots in the Milky Way. There is a well-known dark cloud called The Coalsack by the Southern Cross. It is around 600 light years away. The dust, more like smoke, comes off old red stars. These clouds eventually coalesce into new stars.

The Clouds of Magellan, LMC and SMC, in the lower southern sky, are luminous patches easily seen by eye in a dark sky. They are two small galaxies about 160 000 and 200 000 light years away. The Large Cloud is about 5% the mass of the Milky Way; the Small Cloud is about 3%.

*A light year (l.y.)is the distance that light travels in one year: nearly 10 million million km or 1013 km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes sunlight four years to reach the nearest star, Alpha Centauri.

Newsletter editor:

Alan Gilmore Phone: 03 680 6817
P.O. Box 57 Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Lake Tekapo 7945
New Zealand

the solar system in june 2015

Dates and times are NZST (UT + 12 hours) unless otherwise specified. Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

The southern winter solstice is on the morning of June 22. The Sun will be furthest north at 4.38 am (June 21, 16:38 UT).

Sunrise, sunset and twilight times in june

                       June  1  NZST                June 30  NZST
                    morning  evening                 morning  evening
            rise:   7.33am,  set:  5.03pm    rise:   7.45am,  set:  5.03pm
Twilights
  Civil:    starts: 7.06am,  ends: 5.31pm    starts: 7.16am,  ends: 5.32pm
  Nautical: starts: 6.31am,  ends: 6.06pm    starts: 6.42am,  ends: 6.07pm 
  Astro:    starts: 5.58am,  ends: 6.39pm    starts: 6.08am,  ends: 6.41pm

June PHASES OF THE MOON (times as shown by GUIDE)

  Full moon:     June  3 at  4.19 am (Jun  2, 16:19 UT)
  Last quarter:  June 10 at  3.42 am (Jun  9, 15:42 UT)
  New moon:      June 17 at  2.05 am (Jun 16, 14:05 UT)
  First quarter: June 24 at 11.03 pm (11:03 UT)

The planets in june

Mercury becomes visible in the dawn sky by the end of June. Venus gets a little higher in the evening sky and almost catches up with Jupiter at the end of the month. Saturn is easily visible all evening, setting well after midnight. Mars is at conjunction mid June so not visible this month.

Pluto will occult a magnitude 12.2 on the morning of June 30. The event is predicted to be visible from New Zealand.

Mercury was at inferior conjunction at the end of May, following which it moves into the morning sky. It will remain too close to the Sun to see for much of the month, but will be briefly visible in the brightening dawn sky towards the end of June.

The planet is in Taurus all month, starting June some 3.5° from the brightest star, Aldebaran. The two will then be too close to the Sun to see. Mercury moves away and up from Aldebaran until becoming stationary on June 12. Following that Mercury reverses direction and moves towards the star, with the two closest on the morning of June 24, 2° apart. With a magnitude 0.6 the planet will be a shade brighter than the star. At beginning of nautical twilight at 6.40 am when the Sun will be 12° below the horizon, the two will be a low 8° up, 30° round from east. Aldebaran will be to the right of Mercury and slightly higher.

By June 30, Mercury will have moved further to be below Aldebaran, but will have brightened to magnitude 0.0. At 7am it will again be some 8° above the horizon, only a few degrees east of northeast. Aldebaran will be 6.5° above it. The end of June will give the best chance to catch a glimpse of Mercury at its apparition in the morning sky.

Venus sets more than 3 hours after the Sun during the June, making it readily visible to the west after sunset. Half an hour after sunset will find Venus more than 20° up in a direction well north of west. It starts the month in Gemini, but from 3rd to the 24th will be crossing Cancer. During the last few days of the month it is in Leo, closing in on Jupiter. On the 30th the two will be just over half a degree apart. They are closer still on July 1.

The crescent moon joins the party on June 20 when it will be just over 5° from Venus and a little further from Jupiter.

Mars is at conjunction with the Sun mid June. At conjunction Mars will be 232 million km beyond the Sun and 384 million km from the Earth. Mars will be within 4° of the Sun throughout June, as seen from Earth, so much too close to the Sun to see.

Jupiter is an early evening object, setting about 10 pm on June 1 and a couple of minutes after Venus on the 30th. It moves from Cancer to Leo on June 1 ahead of Venus which almost catches up with Jupiter by the end of June.

The crescent moon is closest to Jupiter on the 21st when the two will be 5.5° apart. This is one evening after the moon's approach to Venus. By June 30 Venus and Jupiter will be a brilliant pair less than 1°.

Mutual events of jovian satellites

There are about 5 mutual events of Jupiter's Galilean satellites observable from NZ during June. One occurs when Jupiter is very low. Better placed ones are:

June  1,  Europa occults Io, mid event ca 8.46pm, duration 3.7 min,
          altitude ca 12°, az 307° 
June  4,  Ganymede occults Io, mid event ca 7.17pm, duration 29.1 min
          altitude ca 22°, az 324°  
June  6,  Io occults Europa, mid event ca 6.33pm, duration 5.6 min
          altitude ca 26°, az 333° 
June 22,  Europa occults Ganymede, mid event ca 7.25pm, duration 4.9 min
          altitude ca 15°, az 309°

This is almost the end of the current series of mutual events

Useful observations and timings of these events can be made by those set up for the video observation of minor planet occultations.

Users of Dave Herald's Occult program can generate their own predictions of these and other events. Hristo Pavlov's Occult Watcher programme will also list them and has diagrams showing the satellites relative to Jupiter. Details can also be found on the IMCCE web site, http://www.imcce.fr/phemu/ where predictions and requirements for observing and reporting information are available.

Saturn is visible all evening following its May 23 opposition. It doesn't set until several hours after midnight. The planet is in Libra moving slowly in a retrograde, westerly, sense as the Earth overtakes the planet.

The moon passes Saturn twice during the month. The first occasion is on June 1 when the 98% lit moon will be 5° from Saturn at midnight. The two will be only slightly further apart at 6 pm on the 2nd. The moon will pass Saturn again on June 29. Early evening the 91% lit moon will be a little under 4° below Saturn. They will be nearly 6° apart by midnight with the moon now to the upper right of Saturn due to the rotation of the sky.

Outer planets

Uranus is a morning object in Pisces rising more than 4 hours before the Sun on the 1st and rather over 6 hours before it on the 31st. The planet's magnitude is 5.9 to 5.8, so readily visible in binoculars

Neptune rises just before midnight on June 1 and 2 hours before on June 30.. The planet remains in Aquarius at magnitude 7.9. It is stationary on June 12 after which is recommences its easterly motion.

Pluto is in Sagittarius rising near 7.24 pm on the 1st and 2 hours earlier on the 30th about 24 minutes after sunset. Its magnitude will be 14.3. On the 30th Pluto will occult a 12.2 magnitude star at about 4.52am (June 29, 16:52 UT). The predicted path of the occultation is very promising for New Zealand. Video observations and light curves are wanted!

Brighter asteroids:

(1) Ceres is in Capricornus most of June, it moves into Microscopium on the last day of the month. It rises just before 9pm on the 1st and at 6.41 on the 30th. On June 22 Ceres will be 12', less than half the full moon's diameter from the 4.1 magnitude star omega Cap. The asteroid will be to the left of the star

(4) Vesta is a morning object in Pisces until June 21 when it crosses into Cetus. It brightens slightly during June from magnitude 7.9 to 7.6. Vesta rises at 1.18 am on June 1 and just after midnight on the 30th.

Brian Loader  
New Zealand

The Evening Sky in May 2015

Download a PDF containing this chart, additional charts for specific areas of the sky and descriptions of interesting objects visible at this time of year.

The Evening Sky in May 2015

Three bright planets and the brightest stars share the evening sky this May. Soon after sunset brilliant silver Venus appears low in the northwest and golden Jupiter in the north. As the sky darkens Sirius, the brightest star, appears northwest of the zenith. Canopus, second brightest, is southwest of overhead. Midway up the southeast sky are 'The Pointers', Beta and Alpha Centauri.

By 8 pm, the time for this chart, Venus is near setting and Jupiter is in the northwest. Arcturus is rising in the northeast, often twinkling red and green as the air breaks up its orange light. Saturn, similar in brightness to Arcturus, is due east. To its right is orange Antares.

Below Sirius are bluish Rigel and reddish Betelgeuse, the brightest stars in Orion. Between them is a line of three stars: Orion's belt. To southern hemisphere star watchers, the line of three makes the bottom of 'The Pot', now tipped on its side. Sirius, 'the Dog Star', marks the head of Canis Major the big dog, now head down tail up in the west.

Crux, the Southern Cross, is southeast of the zenith, to the right of 'The Pointers'. Alpha Centauri, the brighter Pointer, is the closest naked-eye star, 4.3 light years* away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away. Canopus is also very luminous and distant: 13 000 times brighter than the sun and 300 light years away.

Orange Antares, right of Saturn, marks the body of Scorpius, the Scorpion. Antares means 'rival to Mars' in Greek for the planet and star are often similar in colour and brightness. Antares is a red-giant like Betelgeuse; 600 light years away and 19 000 times brighter than the sun.

Arcturus, in the northeast, is the brightest red star in the sky but, at 37 light years, is much closer than Antares. It is about 120 times brighter than the sun. Arcturus is a fast-moving star. In 800 years it shifts a full-moon's diameter against background stars. That is because is moving across the common stream of stars like the sun orbiting in the Milky Way. It has this track probably because it originated in a galaxy that collided and merged with the Milky Way.

The Milky Way is brightest in the southeast toward Scorpius and Sagittarius. In a dark sky it can be traced up the sky past the Pointers and Crux, fading toward Sirius. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 30 000 light years away, is in Sagittarius. The nearby outer edge is by Orion where the Milky Way is faintest. A scan along the Milky Way with binoculars shows many clusters of stars and some glowing gas clouds, particularly in the Carina region and in Scorpius.

The Clouds of Magellan, LMC and SMC, are midway down the southern sky, easily seen by eye on a dark moonless night. They are small galaxies. The Large Magellanic Cloud is 160 000 light years away and is about 5% the mass of our Milky Way galaxy. The Small Cloud is around 200 000 light years away and 3% the mass of our galaxy. That's still many billions of stars in each.

At the beginning of May Jupiter sets around midnight, reducing to around 10 pm by month's end. Jupiter is 810 million km away. It is always worth a look in a telescope. Its four big moons look like faint stars near the planet. One or two can be seen in binoculars if you can hold them steadily enough. All four are easily seen in any telescope magnifying 20x or more. The Moon will be near Jupiter on the 24th. Saturn is a great sight in any telescope with its rings now near maximum tilt. It is closest to us this month, 1340 million km away. Titan, its biggest moon, orbits four ring diameters from the planet. Three or four smaller moons can be seen in larger telescopes closer to Saturn.

Venus is 130 million km away. It is catching us up from the far side of the sun. In a telescope it looks like a featureless gibbous moon, half the size of Jupiter.

*A light year (l.y.)is the distance that light travels in one year: nearly 10 million million km or 1013 km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes four years to reach the nearest star, Alpha Centauri.

Notes by Alan Gilmore,
University of Canterbury's Mt John Observatory,
P.O. Box 56,
Lake Tekapo 7945,
New Zealand.
www.canterbury.ac.nz

Dates and times are NZST (UT + 12 hours) from May 5 unless otherwise specified. Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

Sunrise, sunset and twilight times in may

                       May  1  NZST                May 30  NZST
                    morning  evening                 morning  evening
            rise:   7.04am,  set:  5.30pm    rise:   7.33am,  set:  5.03pm
Twilights
  Civil:    starts: 6.38am,  ends: 5.57pm    starts: 7.05am,  ends: 5.33pm
  Nautical: starts: 6.06am,  ends: 6.30pm    starts: 6.31am,  ends: 6.06pm 
  Astro:    starts: 5.34am,  ends: 7.02pm    starts: 5.57am,  ends: 6.39pm

May phases of the moon (times as shown by guide)

  Full moon:     May  4 at  3.42 pm (03:42 UT)
  Last quarter:  May 11 at 10.36 pm (10:36 UT)
  New moon:      May 18 at  4.13 pm (04:13 UT)
  First quarter: May 26 at  5.19 am (May 25, 17:19 UT)

The planets in may

Mercury and Mars are both too close to the Sun to observe for a second month. Venus continues to get higher in the evening sky while Jupiter gets lower setting around 10 pm by the end of May, so is best observed early evening. Saturn is at opposition on May 23, so is best viewed late evening and early morning.

Mercury sets 45 minutes after the Sun on May 1. It is at its greatest elongation 21° east of the Sun on the 7th. Although it will then set 53 minutes after the Sun it will be too low for observation. It is at inferior conjunction between the Earth and Sun at the end of May. Mercury will then be about 2° south of the Sun with its unlit side towards the Earth. At conjunction Mercury will be 70 million km from the Sun and 82 million km from the Earth.

Venus sets 2 hours after the Sun on the 1st and 3 hours after it on the 31st. On May 1 Venus will be 13° up half an hours after sunset. The planet will be in Taurus some 3° above El Nath, beta Tau, at magnitude 1.7 the second brightest star in Taurus. Venus moves to the east into Gemini on the 8th. By the 31st, half an hour after sunset Venus will be 20° above the horizon to the north of northwest. It will then be 4° above Pollux, at magnitude 1.2 the brightest star in Gemini.

On the evening of May 21 the crescent moon, 11% lit will be 9° to the left of Venus. The following night the moon will be a similar distance above Venus.

Mars sets only half an hour after the Sun on the 1st. By the 31st this has reduced to only 10 minutes later. Conjunction occurs in mid June.

Jupiter will be best placed for viewing as the sky darkens following sunset. On the 1st it is highest, 31° and due north at transit, 6.49 pm. By the end of May, Jupiter transits at sunset and will be 30° up at 6pm an hour after sunset. Altitudes are for the latitude of Wellington. The planet will be a little higher further north and lower further south in NZ

The time Jupiter sets gets steady earlier during the month from a few minutes before midnight on the 1st to a few minutes after 10 pm on the 31st. It will be in Cancer rather distant from any bright stars. It will be moving slowly to the east in the direction of Regulus, but remain 15° from the star by the end of May.

Mutual events of jovian satellites

There are about 10 mutual events of Jupiter's Galilean satellites observable from NZ during May. Some occur very soon after sunset or when Jupiter is very low. Better placed one include:

May 3, Callisto occults Ganymede, mid event ca 10.40pm, duration 6.8 min, altitude ca 10° May 5, Io eclipses Europa, mid event ca 8.16pm, duration 5.3 min, magnitude change of Europa 1.5, so easy to detect May 13, Ganymede occults Io, mid event ca 6.07pm, duration 5.5 min May 17, Io occults Ganymede, mid event ca 8.12pm, duration 4.9 min May 20, Ganymede occults Io, mid event ca 9.05pm, duration 6.4 min May 25, Europa occults Io, mid event ca 6.28pm, duration 3.5 min May 27, Ganymede occults Europa, mid event ca 8.03pm, duration 7.3 min,

this occultation is total for about 90 seconds.

Useful observations and timings of these events can be made by those set up for the video observation of minor planet occultations.

Users of Dave Herald's Occult program can generate their own predictions of these and other events. Hristo Pavlov's Occult Watcher programme will also list them and has diagrams showing the satellites relative to Jupiter. Details can also be found on the IMCCE web site, <a href="http://www.imcce.fr/phemu/">http://www.imcce.fr/phemu/</a> where predictions and requirements for observing and reporting information are available.

Saturn is at opposition on May 23. It rises just over an hour after sunset on May 1 and about half an hour before sunset on May 31. The planet starts the month in Scorpius near beta1 Sco (mag 2.6). It moves slowly to the west through the stars during May, crossing into Libra on May 11.

At opposition on May 24, Saturn will be slightly less than 9 AU, 1341 million km from the Earth and 10 AU, 1493 million km from the Sun.

The almost full moon will be just under 4° to the left of Saturn on the evening of May 5. The two are closest about 4am on the morning of May 6.

At present Saturn's north pole is tilted 25° towards the Earth. This brings the northern surface of the rings well into view. They should be visible in binoculars, although a small telescope is likely to give a better view.

Outer planets

Uranus is a morning object in Pisces rising 2 hours before the Sun on the 1st and rather over 4 hours before the Sun on the 31st. The planet's magnitude is 5.9, so readily visible in binoculars

Neptune rise a little over 5 hours before the Sun on May 1. By the 31st it rises just before midnight. The planet remains in Aquarius at magnitude 7.9

Pluto is in Sagittarius rising near 9.30 pm on the 1st and 2 hours earlier on the 31st. Its magnitude is 14.3.

Brighter asteroids:

(1) Ceres is in Capricornus during May, its magnitude ranging from 8.9 to 8.5 through the month. It rises a little before 11 pm on the 1st and at 9 pm on the 31st.

(4) Vesta is a morning object in Aquarius for most of May, but moves into Pisces on the 29th. Its magnitude is close to 8.0 all month. Vesta rises at 2.20 am on May 1 and 1.20 am on the 31st.

Brian Loader  
New Zealand

The following PDFs are extended versions of the Evening Sky articles including extra charts and descriptions of additional objects of particular note in the month's sky.

The numbers on the end of the file name are the year followed by the month number.

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