This month’s night skies are book ended by Jupiter and Mars after Sunset and by Venus and Saturn before the dawn. The southern part of the heavens is dominated by the brilliant orange star Arcturus. Well to its lower right, are the blue-white stars Spica and Regulus. But the region to the left of Arcturus boats only the faint stars of two giant constellations, Ophiuchus and Hercules.
Stars:-
May is the first month when the constellation of Orion is absent from the night sky altogether, and of the prominent winter stars only Capella in Auriga the Charioteer and Castor and Pollux in Gemini remain above the western horizon. The Plough or Ursa Major (the Great Bear) is still more or less overhead with the pointers pointing to the North Star. The ‘W’ of Cassiopeia is now very low down although still easily visible in the north western sky.
It is also a good month to look for another of the circumpolar constellations; Draco the Dragon. Circumpolar constellations such as the Plough, Cassiopeia and Draco are visible all year around; this is because these stars are above the Earth in space.
Draco is represented by a stream of stars that winds its way around the North Star, so although it has no really bright stars it is still quite easy to identify. The stream starts roughly between the pointers of the Plough and the North Star, then winds its way past the Plough making off in the general direction of Cepheus.
It then turns and ends up at the ‘Dragon’s Head’, a quadrilateral of four stars near the bright star Vega, which is one of the stars that forms the Summer Triangle.
There is one notable star to mention in Draco and this is Thuban, which is not prominent in brightness and is located between Mizar, in the Plough, and the orange star Kocab, in Ursa Minor.
Use the Plough, to draw a line down following the curve of the handle to the bright orange star Arcturus in Bootes the Herdsman which is now very high up. Your downward curve will take you to Spica in Virgo the Virgin. Both Arcturus and Spica are almost due south.
High in the South West can be found Leo the Lion with its bright star Regulus, at the base of a distinctive looking ‘backwards question mark’ of stars. The small quadrilateral of stars that form Corvus the Crow is still quite conspicuous low in the south, while further to the south west and low down is the orange star Alphard, the brightest star in the constellation of Hydra the Water Snake. Alphard is often called ‘The Solitary One’ because of the lack of bright stars near it.
In the North East, two of the stars that form the summer triangle can be seen; Vega, in Lyra the Lyre, has reached a respectable altitude and Deneb in Cygnus the Swan is now becoming noticeable. The third point in the triangle, Altair in Aquila the Eagle, has yet to appear.
Planets:-
MERCURY
The innermost world will be too close to the sun to be visible this month.
VENUS
Rising around 4am as the brilliant morning star, with a magnitude of –4.6. You can’t miss Venus low on the eastern horizon before dawn breaks. The crescent Moon is nearby on the morning of the 24th of the month.
MARS
The red planet can be located in the constellation of Cancer, between the star Regulus in Leo and the twin stars of Gemini; Castor and Pollux. Shinning at magnitude +1.1, Mars falls below the horizon around 2am. On the nights of the 3rd to the 5th of May, the red planet skims the top of the Beehive star cluster M44, with the half Moon nearby on the 3rd of May. The crescent Moon lies to the right of Mars again on 31st May.
JUPITER
Brilliant Jupiter lies low in the north-west sky. Its fading as the Earth moves away from the giant planet. But with a magnitude of –1.9 Jupiter is still more brilliant than any of the stars. The king of planets lies in the constellation of Taurus and falls below the horizon about 11pm, by the end of May. The gas giant is sinking into the evening twilight. On the 28th of this month you may catch a thin crescent Moon above Jupiter.
SATURN
The ring world will be clearing the dawn horizon about 4am. Saturn will be to the lower right of Venus at the start of the month. As May progresses Saturn moves to the right in the sky, rising earlier and becoming more visible against a darker sky. Shinning at a magnitude of +1.1, the ring world lies in the constellation of Pisces. The crescent Moon is nearby on the morning of the 22nd and 23rd of this month. If you have a low power telescope have a look at Saturn and you will see that it has changed its appearance since it was visible in the evening sky at the start of the year. In March the Earth passed through the plane of Saturn’s rings, so instead of seeing these appendages from the top, we are now looking up at the rings from below.
URANUS
This distant world will be lost in the Suns glare this month.
NEPTUNE
Dim Neptune will be too close to the Sun for observation this month.
PLUTO
Can be found in the constellation of Capricornus. It will always be low down in the west and only visible in a ten-inch or larger telescope in a truly dark sky for a short period of time. Pluto rises above the horizon about 2.20am and has a magnitude of +14.5.
CERES
The largest object in the asteroid belt can be located in the constellation of Cetus this month. At Magnitude +8.3 it rises around 4.30am and will be viable for the remaining dark hours.
Special Events:-
Halley’s Comet reappears this month!. Well not the actual beast, but dirt from its skirt which burns up above our heads as a shower called the Eta Aquarids. This shower, which will peak in the early hours of the mornings of the 5th and 6th of May is predicted to be unusually intense this year. There will be a New Moon a few days after the peak so it should be a good year to observe the show.
Phases of the Moon: –
First quarter 4th May
Full Moon 12th May
Last quarter 21st May
New Moon 28th May