The Night Sky This Month

Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during September 2019.The PlanetsJupiter, shining on the 1st at magnitude -2.2 and falling to -2 during the month, can be seen in the south as darkness falls. As the month progresses, its angular size drops from 39 to 36 arc seconds. Jupiter, in the southern part of Ophiuchus, ended its retrograde motion on the 11th of August and so is now moving away from Antares in Scorpius initially lying some 7 degrees up and to its left. A highlight gives the times when the Great Red Spot faces the Earth. Sadly it is heading towards the southernmost part of the ecliptic so, as it appears in the twilight, it will only have an elevation of ~13 degrees (from central UK). Happily, its elevation will only have dropped by a degree or so an hour later in full darkness. With its low elevation, atmospheric dispersion will take its toll and an atmospheric dispersion corrector would greatly help to improve our views of the giant planet. Sat