Sky Notes for August 2013 with James Abbott #stargazing

The annual Perseid meteor shower reaches maximum activity on August 12th at 5pm BST. So both the pre-dawn period on the 12th and the night of 12th/13th could see the highest activity. This year circumstances are very favourable as the young Moon will have set soon after 10pm BST on the 12th, leaving the rest of the night Moon free.

perseids

The shower radiant climbs higher in the sky as the night progresses. By 11pm BST the radiant, below Cassiopeia, is about 40 degrees up in the North East. If it is clear then away from streetlights it should be possible to see a meteor on average about once a minute at peak although for several nights either side of maximum it is worth observing. What often happens is that several come along in quick succession, then a gap before the next burst.

Useful dark sky observing periods return this month free from the summer twilight. By the end of the month astronomical twilight ends by 10pm BST.

Saturn is still visible in the evening twilight in the West but by months end is getting low. A young crescent Moon will be near the ringed planet on the 12th. A superb image was recently captured by the Cassini probe looking back at Earth with the benefit of the Sun being eclipsed by Saturn. Although less spectacular than our view of Saturn, the pale blue colour of our little island in space is striking, with the Moon alongside.

Image: NASA/JPL

Full Moon this month is on the night of the 20th/21st, reaching 30 degrees in altitude when due South.

Through August the early autumn constellations become more prominent in the East, including Pegasus and Andromeda. From dark sites it is just possible to see the Andromeda Galaxy (M31) with the unaided eye. Averted vision can help (looking just to the side of the target).

M31 is the most distant object readily visible without optical aid, over 2 million light years away. Like our own Milky Way galaxy, Andromeda is a “grand-design” spiral. In binoculars it appears as a large elliptical hazy patch. With a telescope it is possible to see more detail and structure, including some of the many dwarf galaxies that orbit around it.

Image: Adam Evans

A recent paper suggests that as well as our future predicted interaction with our “sister” galaxy, we have actually been in a gravitational dance with M31 for billions of years with a previous ancient glancing collision billions of years ago evidenced by the polar rings that both galaxies have. The paper also raises the stakes on the Dark Matter V MOND (Modified Newtonian Dynamics) debate.

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

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

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Posted on 31 July, 2013, in Astronomy News, Observing News, Stargazing and tagged , , , , , , . Bookmark the permalink. Comments Off on Sky Notes for August 2013 with James Abbott #stargazing.

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