Sky Notes for April 2013 #stargazing

In astronomical terms, Spring advances rapidly during April, but so far in 2013 meteorological Spring has been struggling to make any ground against a prolonged winter chill from the East. By the end of April daylight hours are essentially those of summer – with full daylight plus twilight lasting from 5am to 9pm BST. The Sun is still far enough below the Northern horizon during the night for there to be some hours of full darkness to view the stars.

Those hours of darkness may yet be an opportunity to see the Northern Lights from Essex. So far this solar cycle, the Sun has been relatively quiet, despite being near the maximum of its 11 year cycle. However, the time around the Spring Equinox is well known for producing active auroral displays. Moonlight and streetlights are major obstacles to seeing the aurora and so the best window of opportunity will be the first half of the month as the Moon is Full on the 25th – and of course a dark site. If the Earth is in the firing line of a major flare, with the many solar observatories on Earth and in space, not only can we see the flare event, we can predict the timing of the impact with the Earth’s magnetic field that can lead to bright aurora. A good source on this is


The waxing gibbous Moon will interfere with observations of the Lyrid meteors which are expected to peak on the night of the 21st/22nd but a few brighter meteors may still be seen in the late evening emanating from near Vega.

Jupiter finally starts to slip away into the evening twilight as April progresses, but before it is lost behind the Sun’s glare there is a fine conjunction on the evening of April 14th with the young crescent Moon passing just 2 degrees below the planet. The only other major planet readily observable is Saturn which by late April is about 20 degrees up in the South East in the late evening. The Full Moon passes 4 degrees – about 8 Moon widths – below Saturn on the evening of the 25th.


Despite the worst efforts of the weather, Comet C/2011 L4 (Pan-STARRS) was seen from Essex, from the evening of March 12th onwards, low in the Western twilight. In binoculars it showed a bright coma of mag +1 and a slightly curving tail of up to 1 degree in length.

This image, taken on the 13th March is similar to the visual appearance through binoculars at the time:

Image by David Warrington

Image by David Warrington

The comet is now fading as it moves away from both the Sun and the Earth but is still worth chasing in binoculars or a wide field telescope as it is displaying a very broad dust tail. In the first week of April it glides past the Great Andromeda Galaxy M31 before crossing into Cassiopeia on the 9th. On the 20th – 22nd it passes less then 2 degrees to the East (left) of beta Cas, the top right star in the W of Cassiopeia. The comet becomes circumpolar in April and so can potentially be followed all night – and at last can be seen against a dark sky, albeit still fairly low in the North.

James Abbott is an astronomer, NEAS member and CfDS Regional Information Officer.

You can download a free map of the evening sky here:


Posted on 4 April, 2013, in Astronomy News, Observing News, Popular Science, Stargazing and tagged , , . Bookmark the permalink. Comments Off on Sky Notes for April 2013 #stargazing.

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