OCTOBER 2013


The Moon

 

New                             5th    07:45 - 18:28
First Quarter                12th  15:03 - 00:00
Full                              19th   18:07 - 08:08
Last Quarter                 27th  0:00 - 14:35

 
“They” put the clocks back this month, on the 27th I think. Fortunately they don’t take away any photographs I may have taken during the time lost.

There is a Partial Lunar Eclipse this month, it’s not the umbra of the Earth’s shadow that comes across the moon but the penumbra so isn’t very special and may not be easily seen. Nonetheless it will happen on the 19th and start at 11pm and end at 2:45am, with the maximum at about 12:30am. It should darken the lower part of the moon.

 


Planets

Mercury is too close to the Sun all month, not necessarily close in angular distance, but it sets at virtually the same time so will not be easy to see.

Venus is visible in the evening of the 1st, up to half an hour after the Sun has set. In very bright twilight it should be easy enough because of its brightness, mag -4.2. Its 19 arc sec disc will be 62% illuminated. By mid-month that should have extended to nearly

an hour between Sun set and Venus set. The planet will also be brighter at mag -4.3 and closer to us showing a 57% illuminated disc of 21 arc sec. At the end of the month it will set 90 mins after the Sun and be brighter still at mag -4.4 ( it doesn’t get much brighter) and its 25 arc sec disc will show a phase of 50%. See if you can photograph that. A telescope may be needed to show the phase.

Mars raises its 4 arc sec disc above the parapet in the east at 3:15am on the 1st, at mag 1.6. A bit too small to see much detail and it’ll be overcome by dawn twilight in an hour or two. Two degrees above it will be comet ISON at mag 10.4 with a thin crescent Moon some 7° below. On the 15th it will rise at 3am, accompanied by comet ISON a degree above it at mag 9.3 (as forecast), and Regulus, at mag 1.36, less than a degree below. And so they will march into the dawn twilight about 3 hours later. Plenty of time to try to catch them with a camera. On the 31st, it will rise at 2am, a little brighter by 0.1 mag and 5 arc sec in diameter. Dawn twilight will be 4 hours away but it is really too small for much detail to be seen. On the 30th, comet ISON will be 6° below it at mag 7.7(forecast), and another thin crescent Moon, waning this time, 8° below and to the south. Comet Encke will also be close, at mag 7.7 and 24° to the north, but at the same altitude. A wide angle view may catch them all, including Denebola between them.

Jupiter will rise in Gemini, on the 1st, at 12:30am in the ENE, a mag -2.2/38 arc sec disc. Dawn is 5 hours away so plenty of time for observing. By the 31st, it will be mag -2.4/41 arc sec and rise at 9:30pm. It will get as high as 54° above the southern horizon, so a good appearance this year. Make the most of it.

Saturn will set an hour after the Sun, but will not be much to look at in twilight and in the murky air of the horizon. It will be at mag 0.7 and show a 15 arc sec disc. By the end of the month it will set 20 mins after the Sun and 5° away, so too close to seek with optical aid.

Uranus will rise at 6:45pm on the 1st, in evening twilight, a mag 5.7 disc of 4 arc sec. It changes little over the year. It will set at 7:15am, so you’ll have from dusk to dawn to study it. You may have difficulty in finding it on the 3rd and 4th, as it will be within the Earth’s shadow, so will not be lit by the Sun, though the distances are so great that the Sun’s light may yet reach it having passed round Earth. Worth the effort to test it out on those two nights. On the 31st it will rise at 4pm, in twilight, and set 3:45am, with all the night to work on it.

Neptune will rise in Aquarius on the 1st, at 6pm, a tiny blue dot at mag 7.8, and will set at 3:45am. On the 31st, it will rise in daylight at 2:45pm and set at half past midnight, still within the boundaries of Aquarius. So far away that it seems not to move any more than the stars.

Meteor Showers. The only one of any worth is the Orionids peaking on the 21st. Bright meteors emanating from the radiant in Orion, but with the almost full Moon in neighbouring Taurus they may not appear so bright.

Comets. C/2012 S1 ISON is the one that is supposed to blow our socks off. Well, it starts to brighten quite sharply from mag 8 on the 27th, to mag 7.6 on the 31st. It is accompanied by that old periodic comet 2P/Encke, also at the same brightness and within 20° of ISON, rising in the east at about 2:20am on the 30th. They will be

chaperoned by a fat crescent Moon within 6° of ISON as they rise. But there will be an hour and a half to observe them before twilight spoils it.

They both continue to brighten into November mornings, and by the 16th ISON should be mag 4.9, having come above the horizon at 4:45am, but twilight isn’t more than an hour away. Encke rises on the 16th at 5:30am and of similar brightness, but, again dawn approaches and as the morning lightens, they both fade away. They are both moving very quickly too as they rush round the back of the Sun, ISON much the faster. We get a second chance in December as ISON rises in the mornings but fading into dawn twilight as in November. It will be moving away from us and towards the Pole giving us more opportunities to observe. It will also slow down, making the photography easier. By the 23rd of December it should be circumpolar and at mag 5.0 still visible naked eye all night.

To find a comet yourself, go to http://minorplanetcenter.org/iau/Ephemerides/Comets/index.http://minorplanetcenter.org/iau/Ephemerides/Comets/index.html .

The latest comets 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.