April 2010

The Moon

Last Quarter on the 5th - rising at 02:49 and setting at 09:55
New on the 14th at 13:30.
First Quarter on the 21st - rising at 11:06 and setting at 02:46
Full on the 28th - rising at 21:11 and setting at 04:58

The Sun. If you have access to solar observing equipment you’ll be pleased to see that this solar “season” seems to have finally started. A steady stream of sun spots has been seen over the last month and it’s likely to continue. For a quick check on what’s on the Sun’s face go to http://myweb.tiscali.co.uk/boatman/photographssol.html .

Planets
Jupiter. Not visible in the first half of the month but getting easier by the middle, but only in the dawn twilight, as a bright, mag –2.1 disc, low in the east about half an hour before the Sun rises, getting easier as the month progresses. The Galilean moons will be seen but there’ll not be any detail on the disc so low in the sky.
Neptune and Uranus. Very much the same applies to these two, but they rise a little earlier than Jupiter and are of course, much fainter and more difficult to see, binoculars will likely be needed for Uranus and certainly for Neptune.

As all these three rise before the Sun they also set before it, so aren’t visible in the evenings this month, unless you have a well setup GOTO telescope that can find them in daylight.

Venus, on the other hand rises after the Sun so isn’t visible in the mornings but is in the evenings, and in fact presents quite a good sight at mag –3.9, as it descends in the company of mag –0.8 Mercury, 3° away. A good photo opportunity, each evening up to an hour and a half after sunset, from the 1st to the 14th, though they’ll be pulling apart by then to 6°. Mercury at this time will be showing a 63% phase, which should be discernable with a telescope. Then on the 15th, they’ll be joined by the 1day old Moon, a very thin crescent, 3° below. On the 16th, the Moon will be higher than the planets but still within good photographic range and will present a little thicker crescent.
The planets continue to set together but drawing rapidly further apart, Mercury running to the Sun and Venus going the other way towards the Pleiades, making another photo opportunity from the 21st to the end of the month, by which time Venus will be some 20° above the horizon at sunset and will set nearly 3 hours after the Sun.
Mercury, as just mentioned, will spend the first half of the month in the company of Venus, it’ll then continue following the Sun to the western horizon, getting closer and closer to it, to the end of the month, but it’ll be unsafe to observe it with optical aid after the 25th. So in general a good month for Mercury and for Venus, less so for Jupiter, Neptune and Uranus.
Mars will start the month near the top of the sky, still a good sight worthy of close visual study and worth taking webcam pictures too, but getting smaller and fainter through the month till by the end it will have dimmed to mag 0.7, having started the month at mag 0.2. The disc will have shrunk from 9arcsec to 7arcsec, making it more difficult to see detail on the disc. It will though, make a fine wide-angle picture with the Beehive cluster, which will be within a degree of it on the 16th, its closest point. It’ll set by 5am on the 1st and by 3:15am on the 30th, so make the most of it.
Saturn will start the month already well up in the east, and will be available all night, all month, to finally set by the end of the month at dawn. A good month for Saturn too, though it’ll not get higher than some 38° above the horizon in the south, still a good enough height to see detail on the disc, and as the rings are gradually widening, some detail there too. Good seeing should show you up to 7 of its moons.

Meteor Showers. The Lyrids are the only shower this month peaking on the 22nd. Quite a tight shower sending us streaks of fast light from the 15th to the 28th. The presence of the half Moon won’t help. Generally a good shower.

Comets. Comet C/2009 K5 McNaught will be crossing Cygnus low in the northern sky this month but at an estimated mag 9.7 it’ll be no more than a faint fuzzy ball.
81P/Wild is still in the eastern end of Virgo, and will be in the sky all night for the month, but it will need a telescope to see it’s hazy mag 9.7 blob.
C/2007 Q3 Siding Spring is in Draco, 10° below Kochab in Ursa Minor and at mag 11.5 still just a faint blob. All these are estimated magnitudes, but could be wrong in either direction.
Individual star charts can be drawn if you need them, for anything mentioned above, by asking in the comments below, or asking the observatory at http://www.donastro.org.uk
What else?
Very much the same situation applies as did for last month, in that we have a good mix of up and coming galaxies in Coma and Virgo and Leo, and the clusters of the galaxy disc constellations, chief of which is Orion, but that will soon be gone.

Satellites. For these please interrogate http://www.heavens-above.com for the ones you like to see.
Brian