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Sat, 08 Aug 2015 - Perseid maximum is approaching

We are now closing in on this year's Perseid maximum.

The peak is predicted to occur at around 07h UT on the morning of  Aug 13th, which means that the best rates will be seen during the night of Aug 12-13 (Wed-Thurs). Good rates should also be visible on the night before and night after. Indeed, observers are already reporting a good number of Perseids. As ever, bear in mind that you could be clouded out on Aug 12-13 ... so do make use of clear sky on other nights if you can.

Perseids can be seen at any time of the night, but the observed rates on any night will steadily increase as Perseus climbs higher in the sky. For observers in the south of England, the radiant is about 27 degrees above the horizon at the start of the night and climbs to around 66 degrees by the end of the night.  As a result, observed Perseid rates late in the night will be about double those seen at the start. Hence the later that you stay out, the higher the observed rates will become.  

Don't be misled however, by sensational internet posts or poorly written sky diary columns that promise you 100 or more Perseids each hour. This is the ZHR value and observed rates are always somewhat lower than this.

You can however maximise the number of Perseids that you see by choosing as dark an observing site as possible and making sure that you have a clear unobstructed view of the sky. In addition, don't look directly at Perseus - choose an area of sky 30-40 degrees from the Perseid radiant and around 50 degrees above the horizon. This area of sky could be the Square of Pegasus or the area around Polaris in the northern sky.

The location of the Perseid radiant (the location in the sky from which the meteors will appear to have come from, if their paths are traced backwards) is shown in this chart:

Great news is that moonlight will not be a problem around Perseid maximum, with New Moon occurring on Aug 14th.

Indeed, the Moon is (at last!) now moving out of the night sky. It is already rising after midnight BST and by Tuesday morning will be rising at around 02:30 BST (01:30 UT). During the same period, its impact drops significantly, with its illumination falling from 39% (Saturday) to 12% (Tuesday).

Although it is enjoyable to sit back and enjoy the spectacle, it is always good to keep a record of what you have seen. A guide to what to record can be found  here

Do let us know what you have seen. You can email your report to

Do also send us any good images of Perseids that you capture. You can either mail them to the above address or send them to us on Twitter by including @popastro in your Tweet.


Added by: Tracie Heywood