September 2012
Moon
Last Quarter ----- 8th --- 23:05 -- 15:00
New -------------- 16th -- 07:15-- 18:56
First Quarter --- 22nd -- 14:49-- 22:59
Full ---------------30th -- 18:25-- 07:32
This should be a time for Indian Summer but if it continues as it started in spring it’ll be the start of winter. Or am I being over pessimistic? Nevertheless, dress up as though for winter and enjoy the longer nights and the arrival of winter constellations.
Planets
Mercury may be just visible on the 1st of the month, but it rises only 50 mins before the Sun in dawn twilight, and searching for it in those conditions is not advised. It isn’t safe while setting either, so better to avoid Mercury all month.
On the 1st, Venus rises in the east, in Gemini, at 2:15am, at mag –4.2, with a phase of 58°, brilliant. You have 3 hours before the Sun comes up to spoil it. By the 30th, it will rise at 3:15am with a 70% phase, and still 3 hours before sunrise.
Mars is too close to the Sun for observation this month.
Saturn is also too close to the Sun, so avoid it.
Jupiter will rise at 11pm on the 1st of the month, at mag –2.4 and 39 arcsec . It will be there to study for 5 hours before overtaken by dawn. At the end of the month it will rise at 9:30pm giving you much more time to observe. By the end of the month it will also have drawn nearer and show a 43 arcsec disc and be a little brighter.
Uranus will rise due east at 8:45pm, a 4 arcsec blue disc at mag 5.7. It may be hidden in the glare of the almost full Moon just 13° away. At the other end of the month, on the 29th, it will have the same fat Moon within 5°, making it difficult again. The Moon will interfere all night of course, as they pass across the sky together. But only on these two nights. It’ll set on the 30th at 7am as dawn is breaking the sky in the east. You have all night to study it and seek its moons, at least 3 can be seen.
Neptune will rise on the 1st at 8:45pm, as dusk is falling. At mag 7.8 and 2 arcsec, with a big Moon nearby it won’t be easy to find it. It will be almost exactly ESE as it comes up over the horizon, though that might not be much of an aid. As I’ve said before a Goto telescope will help. It will set at 5:30am, so you have it all night to find it. At the end of the month it’ll rise at 5:45pm, and set at 3:15am.
Meteor Showers
Only one with a peak in September and that has only a forecast of 5/hour at the zenith, so hardly worth the effort of laying out in the garden in the cold for.
Comets
None, though I’ll let you know if I hear of any we’re likely to see. Or you can look for yourselves on the Minor Planets site. http://minorplanetcenter.org/iau/Ephemerides/Comets/index.html
The latest from a few years ago, are listed there. Click on one for the ephemeris. If you like it,
download it as a KML file by clicking on the KML file link. Then click on it on your desktop, which is where it’ll land when it gets to your machine. Click on it there and it will ask you to run google earth then to change it to google sky and the path of the comet will be drawn across the google sky for you.
Don’t bother with any that show a mag number larger than 7 or 8. Most on the list are more than 15, which is very faint indeed.
For details of satellites check
http://www.heavens-above.com
and for sky charts call me at
observatory@donastro.org.uk