The night sky in June 2019

posted 31 May 2019, 12:39 by Pete Collins
by Anne Holt

Sunrise       1st::  04.47        30th:   04.43
Sunset        1st:   21.27        30th:   21.41

Astronomical darkness:  none, as the Sun never gets more than 18 degrees below the horizon in June.  We only have a couple of hours of astronomical twilight each night, the Sun is between 12 and 18 degrees below the horizon from around midnight to 2am throughout the month.  The Summer Solstice is on 21st at 16.54.  This is when the Sun reaches its most northerly point in the sky and is overhead at local noon along the tropic of Cancer. This day is 9 hours 33 minutes longer than the Winter Solstice - with the night correspondingly shorter, of course.  The earliest sunrise is on 17th and 18th (04.39), the latest sunset on 25th (21.42).

New Moon: 3rd at 11.01     Full Moon:  17th at 09.30
The June full Moon is known as the Strawberry Moon, as this is the time the fruit ripens.  Other names are the Hot Moon, Mead Moon and Rose Moon.

Lunar Perigee:     8th at  00.23  (368506km)
Lunar apogee:     23rd at  08.52  (404548km)

The moon is at perihelion on 1st at 21.57, when it will be 1.0115 AU from the Sun,  slightly closer than the Earth, which is at 1.0141AU.

Highlights

The amount of light is still far too high for astronomers' liking, we have no astro darkness and only a couple of hours of astro twilight each night.  The naked eye planets are all very low in the sky, only Jupiter is bright enough to be seen easily - and even that only reaches an altitude of 14 degrees. We don't have much in the way of meteor showers, and solar observers don't fare much better either, despite the long days.  We are currently at Solar minimum so there are very few sunspots around. 

The best thing that the sky can offer is more a meteorological phenomenon than an astronomical one - noctilucent clouds which may be visible in twilight, low in the NE, 2 hours to 90 minutes before sunrise and low in the NW, 90 mins to 2 hours after sunset. These colourless or pale blue wispy clouds are too faint to be seen in daylight, they are thought to be formed when water vapour freezes on dust molecules in the very thin atmosphere about 50 miles up. At this altitude they are still illuminated by the Sun, even though it has set for observers on the ground. The first confirmed sighting was as recent as 1885, though there may have been a few around prior to that.  Displays are now becoming brighter and more frequent, thought to be a result of climate change.

Constellations

The Plough asterism in Ursa Major is still prominent, being overhead for much of the night, leaving Cassiopeia on the opposite side of the Pole Star, low in the northern sky. The Summer Triangle, consisting of Vega, Deneb and Altair, is now getting higher in the late evening, though Altair, in Aquila, is still quite low in the early part of the night.  The beautiful double star Albireo, at the head of Cygnus the swan, is very well placed for observing. The Milky Way is now visible from dark sky sites, running across the sky through the Summer Triangle, passing almost overhead in the early hours. The bright orange red Arcturus is shining brightly high in the SW and, if you manage to find some dark skies not obscured by cloud, you should be able to see the rest of the kite shaped Bootes, with the semicircle of stars forming Corona Borealis just to the east of it. Another red giant, Antares in Scorpio is now visible low on the southern horizon.

Planets

Mercury: in Taurus, mag -1.1
An evening object, very low in the sky throughout June.  On 1st it sets at 22.37, about 70 minutes after the Sun but is only 4 degrees above the horizon as the sky darkens.  On the evening of 4th the thin crescent  Moon passes 3 degrees 39 minutes south of the planet during daylight. It might be possible to see them about  30 minutes after sunset, now separated by almost 5 degrees. It moves into Gemini on 6th, setting at  23..04 and slightly higher, 6 degrees at dusk, but fainter at mag -0.7. On 16th it reaches its highest point in the evening sky, about 13 degrees above the horizon at sunset, though much lower by the time the sky is dark enough for it to be seen.  Over the next few nights it appears close to Mars, soon after sunset on 18th they are only 13 arcminutes apart,  with Mars about 3 times fainter than Mercury.  It reaches greatest eastern elongation on the night of 23rd/24th when it appears about 25 degrees from the Sun.  However the angle of the ecliptic against the eastern evening horizon is so small at this time that the planet is now lower in the twilight sky.  It moves into Cancer on 25th and by month end will have faded to mag 0.9, setting at 22.47 and on the horizon at dusk.

Venus:  in Aries, mag -3.9
Still a morning object but very low in the sky.  On 1st it rises at 04.03 and barely gets above the horizon by dawn.  On 1st the thin waning Moon may be seen, about 9 degrees SW of the planet just before sunrise.  They are at their closest, 3 degrees 14', in daylight at 19.15.  It moves into Taurus on 4th.  During the month its apparent distance from the Sun is decreasing but, because the angle of the ecliptic is increasing in the morning sky, it rises about 45 minutes before the Sun throughout June, still just on the horizon by dawn. 

Mars:  in Gemini, mag 1.8
Now very low in the WNW as the sky darkens, on 1st it sets at 23.48 and is only 5 degrees above the horizon at dusk.  On 5th the thin crescent Moon passes one and a half degrees to the left of the planet at 16.06.  The pair, now 4 degrees apart, may be seen in the same binocular field of view as the sky darkens around 22.00. After the first couple of weeks in June it will be very difficult to see as it will have dropped below the horizon before the sky darkens. On 30th it sets at 22.53 and is 3 degrees below the horizon at dusk.

Jupiter:  in Ophiuchus, mag -2.6.
Currently the brightest and best positioned of the naked eye planets, visible for most of the night during June.  On 1st it reaches its highest point at 01.50.  The bad news is that its highest point is only 14 degrees.  However, from a site with a clear southern horizon it is quite unmissable, much brighter than the red giant Antares, a little to the west.  It is at opposition on 10th, when it culminates at 01.10, still no higher in the southern sky but, because of its elliptical orbit, is at its closest to us a couple of days later when it is at a distance of 641 million km. The almost full Moon passes just over 2 degrees from the planet on 16th.  On 30th it should be visible from around 22.00 when it is at an altitude of 11 degrees in the south, culminating  3 degrees higher at 23.37.

Saturn:  in Sagittarius, mag 0.3
Now rising before midnight but,  like big brother Jupiter, very low in the sky. On 1st it rises at 23.56 and culminates just before dawn, at 14 degrees in the south.  On 19th the just past full Moon passes 1.5 degrees SW of the planet at around 3am.  On 30th it rises at 21.57 reaching 10 degrees in the SE by midnight and 14 degrees at 01.54.  It will have brightened slightly to mag 0.1.

Uranus:  in Aries, mag 5.9
Not visible in June. On 1st it rises at 03.25 but is still 9 degrees below the horizon by dawn. On 30th it rises at 01.34 and is just on the horizon as the sky brightens.

Neptune:  in Aquarius, mag 7.9
A telescopic  object not easily seen at the moment because of its low altitude.  On 1st it is on the horizon at dawn but it does improve slightly during the month.  On 24th the gibbous Moon passes 4.5 degrees south of the planet at around 3am.  By 30th it rises at 00.22 and reaches 10 degrees before the sky brightens.

Dwarf Planets

Pluto:  in Sagittarius, mag 14.7
Still very low, so difficult to view through a scope.  On 1st it rises at 00.15 and reaches 14 degrees at 04.09.  On 30th it rises at 22.12 and culminates 4 hours later, still at 14.

Ceres: in Scorpio, mag 7.0
The only dwarf planet orbiting in the asteroid belt, so by far the brightest, is now also in the southern part of the sky.  On 1st it culminates at 00.53, at 18 degrees, slightly higher than Pluto. It fades during the month, down to mag 7.7 by 30th, when it culminates 17 degrees above the southern horizon at 22.32,  setting at 02.52.

Eris:  in Cetus, mag 18.8
Below the horizon during the hours of darkness throughout June.

Haumea:  in Bootes, mag 17.3
Much higher in the sky,  one for experienced astrophotographers to attempt after midnight, especially in the early part of the month. On 1st it culminates at 22.41, before the sky is dark enough but is still at 51 degrees in the SW at midnight.  By the end of the month it is much lower but still at a respectable altitude for a short time -  32 degrees above the western horizon at 00.41, setting nearly 4 hours later.

Makemake: in Coma Berenices, mag 17.1
Not as well positioned as Haumea but not too bad in the early part of June.  On 1st it culminates at sunset but is still at 50 degrees in the SW just before midnight,, setting at 02.15.  On 30th it sets at 04.14 but should be high enough for imaging for about 40 minutes from 00.40, when it is at 27 degrees in the west.

Comets

Another bad month!  46P/Wirtanen and 38P/Stephan-Oterma  are both still in the region of Leo and Leo Minor but both now very low and very faint.  Wirtanen  sets at 03.31 on 1st and 01.41 on 30th, Stephan-Oterma following about 40 minutes later. Magnitudes at the end of June predicted to be around 17 and 14.5 respectively.

There are a few comets, currently very faint but brightening, which might possibly be good photographic targets later in the year.

C2017/T2 (PANSTARRS) currently in Taurus, mag 11.5

C2018/N2 (ASSASSN) now in Cetus, mag 12.4. Predicted peak 10.3 in late October

168P/Hergenrotter, also in Cetus, mag 12.9.  Predicted to reach 11.5 in late August

260P/McNaught in Aquarius, mag 14.5, predicted peak 11.0 in late September.

For more information and exact positions of all solar system objects, at any time see
And, for currently visible comets

Meteor Showers

Still nothing major, just a few very minor, maybe even no longer existing ones.

Ophiuchids:  19th May to sometime in July, peaks given as 10th and 20th, ZHR 5.  A very weak shower especially for northern observers, as the radiant is very low - only 12 degrees above the horizon at midnight.  Often considered to be part of the antihelion source, rather than a separate shower.

June Lyrids:  peak 15th/16th. Not much activity in recent years, though ZHR of 8 to 10 has been recorded in the past.

June Bootids: June 22nd to July 2nd, peak June 27th, ZHR variable.  Not much activity predicted for this year.  Could be a few meteors on 24th.

The antihelion source is active in early and late June, but is better seen from further south, as the radiant is very low. in Sagittarius.

Daytime Arietids.  The radiant of these is only 30 degrees west of the Sun but a few have been seen just before dawn around the peak on June 7th.  ZHR of up to 30 has been recorded by radio and radar observers.






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