Its’ amazing to think that brilliant Jupiter, which has been a feature of our evening skies all year, will be gone by the end of this month. On the15th of the month the Cassini space probe will crash into Saturn at the end of its mission.
This month the nights become longer and we move towards unsettled weather. The autumn constellations are starting to show. Ursa Major, or the Plough, can be found low in the North. The ‘W’ of Cassiopeia is not far from the overhead point
Also on view this month we have, Aquarius the water carrier, Cetus the sea monster, Capricorns the sea goat, Pices the fishes, Piscis Austrinus the southern fish and Delphinus the Dolphin.
The summer triangle of Altair, Deneb and Vega remains high up. The southern sky is dominated by the Square of Pegasus. The bright star Capella in the constellation of Auriga the Charioteer is becoming more noticeable in the east. It will be overhead in winter evenings.
Although the four stars that form the Square of Pegasus are not the brightest, once found they will be easily recognised again. It is always an interesting project to count how many stars you can see within the square; you might be surprised by the result.
If you use the two right hand stars of the square and draw a line to the south you will reach a bright star very low in the sky. This star is Fomalhaut, in the constellation of Piscis Austrinus.
This month on Friday, 22nd September we have the autumn equinox. After this date the nights noticeably lengthen.
As mentioned Jupiter is slipping down into the twilight sky. Setting about an hour after the Sun. It will be lighting up Virgo with a magnitude of –1.6, before disappearing by the months end.
Saturn at magnitude +0.5, lies among the dim stars o Ophiuchus, and sets around 10.30pm.
Distant Neptune is at opposition on 5th of this month and is at its closest to Earth. Visible all night long and it’s nearest and brightest this year. Though bright means a poor magnitude of +7.8. You will need binoculars or a low power telescope to spot in Aquarius.
Uranus, rises at 8pm. At magnitude +5.7 in Pisces.
Rising around 3.30am, Venus blazes at magnitude –3.8, for the first couple of nights of this month. It lies the Praesepe star cluster in Cancer.
Just before dawn Mars at magnitude +1.8 and Mercury brightening from magnitude +1.2 to -0.8 are having a tango in Leo, with it’s brightest star Regulas.
The phases of the Moon are:-
Full Moon September 6th
Last Quarter September 13th
New Moon on September 20th
First Quarter September 28th