We’re entering Noctilucent Cloud territory – see early sighting information here, some faqs here, a page on NLCs at Cumbrian Sky and one of my posts here. As ever, this post is illustrated with a few sky charts showing midnight on the first, last and fifteenth day of the month. The dots represent brighter stars, green circles are star clusters, nebulae, galaxies and the like and the very brightest stars, the Moon and the planets are named when they appear. Sky charts provided using Stellarium.
The Moon will be in the last quarter phase on the 4th, new on the 12th, first quarter on the 19st and full on the 26th. On the 23rd, the dark side of the Moon will occult the 5.4th (just about naked eye visible) magnitude star V913 Scorpii at around 23:42. On the 29th, the 4.9th (naked eye, dim) magnitude star Rho Capricorni will appear from the dark side at 00:43 and on the 30th the 6.4th (invisible to the naked eye, visible in binoculars and small telescopes) magnitude star TYC 5784-01499-1 will appear from the dark at 01:50.
The June Lyrid meteor shower may or may not be active on the 16th. The June Bootids on the other hand could produce activity of ~20-50 overhead meteors per hour on the 23rd-24th, with further activity possible on other dates such as the 27th. There will be a bright Moon and all-night twilight to contend with. The AntiHelion source is a shower from the antisunward direction of a few meteors an hour, which is active at the moment.
Heavens above presently lists five comets above magnitude 12 and eleven asteroids above magnitude 10 in the hours of darkness. The comets are: C/2009 R1 McNaught at 7.8 in Andromeda and getting brighter; 10P Tempel 2 at 9.0 in Aquarius; 141P Machholz at 9.6 in Taurus; C/2009 K5 McNaught at 10.6 in Camelopardalis and 81P Wild 2 at 11.0 in Virgo. Details on the future movements and changing brightness of the comets can be found here. The asteroids are 1 Ceres at 7.5 in Sagittarius, appearing embedded in the Lagoon Nebula, M8, on the 2nd, 4 Vesta at 7.7 in Leo, 2 Pallas at 8.8 in Boötes, 15 Eunomia at 9.6 in Sagittarius, 12 Victoria at 9.6 in Libra, 7 Iris at 9.7 in Aries, 40 Harmonia at 9.8 in Scorpius, 6 Hebe at 9.8 in Aquarius, 3 Juno at 9.9 in Taurus, 129 Antigone at 10.0 in Ophiuchus and 532 Herculina at 10.0 in Coma Berenices. Pluto is also in Sagittarius, shining at magnitude 14.
Mars is on the home stretch to the Sun now. It shines at +1.1, falling to +1.3 by the end. Its angular size falls from 6 arcseconds to 5.2 arcseconds in the same period, making details hard to spot. Its colour will still be vivid though as it starts the month close to the bright blue/white star Regulus.
Venus is now prominent in the evening skies just after sunset. Shining at magnitude -3.9, it is the brightest thing in the night sky after the Moon. It appears in the south-west once the Sun has gone down and has an angular diameter of 13 arcseconds, showing phases like the Moon, rising to almost 15.4 arcseconds by the end of the month. It gets higher and higher above the horizon at sunset with each day of the month. On the 20th, Venus passes through the Beehive Cluster.
Mercury is visible shining in the morning light at magnitude 0 rising to -1 in the first week of June (before being swallowed up by the Sun). It won’t reach any great height in the sky, only about five degrees, you’ll need a clear horizon to the East to see it.
Saturn will remain at an angular diameter of around 18 arcseconds over the course of the month. It presently shines at +1.0, fading to +1.1 by the end of the month. The angular size of the slender rings extending to ~40 arcseconds. Those rings have finally reached their minimum tilt and so will be getting thicker during the month. The bright moon Titan shines at 7.8 and will be easily visible in small scopes and binoculars (unless it is in front of or behind the planet at the chosen viewing time).
Jupiter rises at around 2:30 BST at the start of the month, shining at -2.3, but appears at 01:00 by the end, shining at -2.5. Not much detail visible, but the Galilean moons should be visible in even small telescopes. The planet is close to Uranus during the 6th-10th and increases in diameter from ~39 arcseconds to ~41.
Uranus is also a morning object, shining at 5.7 in Pisces, with an angular size of 3.7 arcseconds. During the 6th-10th, it will be joined closely by Jupiter.
Neptune is also in the morning skies, shining at 7.9 with a 2.3 arcsecond disc in the middle of Aquarius.
A few things outside the solar system
Leo holds the southern spot at sunset, with Cancer to the west of it. In Cancer, not far from Mars, is the Beehive Cluster of stars, good to observe on a dark night. The constellations of Leo, Virgo and the Big Dipper are all home to galaxies, details here. This is probably the worst month of the year to look as the all-night twilight obliterates faint fuzzies.
The Usual Stuff
If you want to watch satellites flaring or passing in the sky (even sometimes during the day), then go to Heavens Above to get times and directions. If you need assistance in deciding where things are in the sky, why not install the free program Stellarium, which does all the work for you? Finally, to avoid the dreaded clouds, Met Check gives a quick forecast and the Met satellites or other satellites can be used to track breaks in the cloud. For an indication of auroral or solar activity, SpaceWeather.com is an invaluable resource. If the stars aren’t available, there’s always solar astronomy. Projections of the Sun onto white card can show sunspots, when properly focused. A good filter (not an eyepiece filter) or a dedicated solar telescope will show better details. Never observe the Sun without filters and never with an inadequate, inappropriate or old (and therefore possibly with holes in) filter.
For young astronomers (ages 9-16) Space Explorers is run in Kendal Museum on the third Saturday of most months from 2:30-4:00 pm. The Society for Popular Astronomy also has a sky map for young astronomers for May here.
Plus why not pop along to the Eddington Society, which meets at Kendal Museum on the first Monday of each month, this month it is on the 7th, with a talk on Astronomy before Copernicus. There will also be a public observing event in Abbot Hall park on the 19th from 8:30pm.
Don’t forget to check back here and on my twitter account for the latest astronomical events in this area.