Lots of planets this month, a rare constellation, a comet, and the nights are drawing in!
Astronomical darkness starts at 22:19 at the start of the month, and 20:49 at the end. For those with the endurance for it, dawn starts at 04:00 on the 1st and 05:10 on the 30th. That’s eight whole hours of full darkness each night by the end of September.
Jupiter is one for the early birds, and by mid-month will be well elevated in the eastern sky before dawn. The four Gallilean moons Io, Europa, Ganymede and Callisto (the ones that Gallileo spotted through a telescope) will be well spread from the main body of the planet and are fairly easy to spot in binoculars.
For photographers, here’s a great opportunity to put Jupiter, the crescent Moon and the Beehive Cluster all in one shot. Framed for a 100mm lens on a DSLR, you’ll catch this in the east on the morning of Saturday 20th, in full darkness until 04:48.
At the more civilised end of the scale, Mars and Saturn will follow the sunset and show themselves in the second half of September, low on the evening horizon to the south west.
Also after sunset, there’s the chance to catch the constellation of Sagittarius, in particular the set of stars (“asterism”) known as the teapot. Sagittarius spends most of the year on or just below our horizon in the UK, and only shows itself around summertime when the skies are too light. Now is the best time to look slightly west of south, about an hour after sunset, where the Milky Way meets the horizon. This is really challenging from Cumbria, where the southern horizon can be spoiled by light pollution, but it can be worth a try. The “steam rising from the teapot” is a collection of nebulae and star clusters in the Milky Way. This SkySafari image also shows comet 67P/Churyumov-Gerasimenko (that’s the one that the ESA are orbiting with their Rosetta probe) in the centre of the teapot asterism, but at magnitude 18 there’s no chance of seeing it.
Comet C/2014 E2 (Jacques) continues its journey down the Milky Way this month, gradually fading as it goes. There will be a fantastic opportunity for astrophotographers on the evening of the 19th, 20th or 21st, as comet Jacques makes its way past the “Coathanger” asterism in the constellation of Vulpecula. Here it is on the 20th, framed for a 200mm lens on a DSLR. Full darkness arrives at 21:18, when the comet is elevated a very reasonable 54º in the southern sky. I’ll be coming home from holiday that weekend, so fingers crossed for clear sky on the Sunday night!
Clear skies to all as usual,