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.
From 20th of September the innermost planet rises above the horizon around 5an. Located well to the left of Venus at magnitude –0.5. Mercury will be at its maximum separation from the Sun on 22nd September.
The morning star appears in all its glory this month, as it speeds upwards in the dawn sky. By the end of the month Venus is rising as early as 3am, which will give us the opportunity to see it against a truly dark sky. It will be at its maximum brightness at magnitude –4.5. There will be a pretty sight when the crescent Moon hangs nearby on the mornings of the 11th and 12th of this month.
The red planet will be too close to the Sun for observation this month.
The gas giant Jupiter, rises about 9pm, at magnitude –2.7. Located in the constellation of Aries. It will be just close to the right of almost last quarter Moon on 4th September.
The ring world lies in the constellation of Aquarius and is above the horizon all night long. At a magnitude of +0.5 it can be found close to Moon on the 26th of this month.
Found in the constellation of Aries. It rises above the horizon about 9pm. At magnitude +5.7 it is just visible to the naked eye, but I much better seen with optical aid. Have your binoculars or telescope ready on the evening of 14 of this month, when Uranus has a very rare occultation with the Moon.
Neptune is located in the constellation of Pisces. The most distant planet is at its closest to Earth on 19th September, and is above the horizon all night long. But even at opposition, Neptune only reaches magnitude +7.8, so you well need binoculars or a low power telescope to see it.
This distant planet can be observed in a ten-inch or larger telescope. It can be found in the constellation of Sagittarius, at magnitude +14.4. It will be setting just after 1.15am.
The largest object in the asteroid belt can be located in the constellation of Virgo. At magnitude +8.93 it should be visible through binoculars or a low power telescope. Setting around 8.45pm.
Special Events: –
4th September – The almost half Moon is just to the left of nearby bright Jupiter. The Pleiades star cluster is just to the left of the Moon.
5th September – The almost half Moon is now immediately below the glimmering Pleiades star cluster. It will be a particularly lovely observation using binoculars, with Jupiter well to the right.
10th September – The crescent Moon lies near the twin stars Castor and
Pollux in the constellation of Gemini.
11th and 12th September – The crescent Moon forms a gorgeous duo with brilliant Venus before dawn breaks.
13th September – A very thin crescent Moon is close to the star Regulus.
18th September – Venus reaches its greatest brilliance as the Morning Star, at magnitude –4.5.
19th September – Visible throughout the night, Neptune is opposite to the Sun, and at it’s nearest to the Earth at 4324 million kilometres.
23rd September at 7.50am – Nights become longer than days as the Sun moves south of the equator at the Autumn Equinox.
26th September – The Moon is near to the planet Saturn.
The phases of the Moon for September are:-
Last quarter – 6th September
New Moon – 15th September
First quarter – 22nd September
Full Moon – 29th September