Posted by on Jan 23, 2018 in Main |

There are the first signs of spring in this month’s night sky even though the winter constellations are clearly on display.


The Plough is now higher in the north east, with its handle pointing in the general direction of the horizon. If you follow the curve of the handle you will come to a bright orange star low in the sky. This is Arcturus in the constellation of Bootes. Arcturus is the brightest star in the spring sky. The ‘W’ of Cassiopeia is high in the north west.

Orion still dominates the southern part of the sky. However, as Orion is a little to the west of south, now is the best time to see Sirius the Dog Star. This is the brightest star in the sky. Using the three stars that form Orion’s belt to form a line, continue down that line and you will reach Sirius.

The stars are a very long way away. Sirius, although the brightest, is in fact very close to us, at around 8.5 light years away.


The other winter stars, Aldebaran and the Seven Sisters in Taurus are now starting to get lower in the west, while Castor and Pollux together with Procyon are now at their highest points. Capella is still high, being just past the overhead position. However, while Capella is very high, Vega, which occupied the overhead point in summer, is now at its lowest, close to the northern horizon.


There is a parade of planets in the early morning sky, lead by Jupiter, rising around 1am. Located in Libra with a bright magnitude of –2.1.


Mars lies to Jupiter’s lower left, and rises about 3am. As the month progresses Mars moves through Scorpius passing close to its brightest star, Antares on the 12th of the month. Antares is similar in brightness to Mars, at +1.0. The name Antares means ‘rival of Mars. This may be a good opportunity to compare their colours.


After 5am Saturn will be located to the lower left of Mars in Sagittarius, with a magnitude +0.6.


The evening sky this month is pretty dull to start with. Uranus, magnitude +5.8 lies in Pisces and sets about 11pm.


Lower down Neptune in Aquarius, magnitude +7.9 sets around 7pm. From mid month it has disappeared into the twilight glow.


In the second half of the month the dusk sky is miraculously transformed as brilliant Venus bursts on to the scene in the western horizon. The evening star blazes at magnitude –3.9, and by the end of February is setting an hour after the Sun.


Venus is joined in the last couple of days of the month by Mercury. Lying to the lower right of Venus and ten times fainter, magnitude –1.4.


On the mornings of the 8th to 11th February the Moon passes close to Jupiter, Mars and Saturn.

Phases of the Moon this month are:-

Last Quarter on 7th

New Moon on 15th 

First Quarter on 23rd