Observing opportunity: Perseid meteor shower 2005

[Rick]

BAA electronic circular No. 00195

Observing opportunity: Perseid meteor shower 2005

Peaking around mid-day on August 12, the Perseid meteor shower is now well into the rising phase of its activity, and those who have already started their observing runs have been treated to reasonable rates (at least 5-6 Perseids/hr) with a liberal sprinkling of bright events showing persistent ionisation trains over the past couple of nights. With the Moon well out of the way - the broad waxing crescent sets before local midnight up to 15 August - the shower is met with favourably dark skies this year.

  Best rates will probably be found late on Thursday-Friday Aug 11-12 and on the evening of Friday-Saturday Aug 12-13, but observers are reminded that coverage of the shower is desirable not just at maximum, and for several nights to either side the activity is sufficiently high to make meteor watches particularly rewarding - if you haven't yet started watching for Perseids, *now* is a good time to start! The period from Aug 8-9 to 15-16 embraces some of the most meteor-rich nights of the year. Highest rates are generally found later in the night when the Perseid radiant near the north end of Perseus at its border with Cassiopeia is high in the eastern sky. Around peak, observed rates of up to a meteor pee minute are possible from clear, dark locations.

   Visual watches are fairly straightforward to carry out - as outlined on the BAAMS webpages at  http://www.britastro.com/meteor

With almost guaranteed high rates, the core interval of the Perseids, which we are now entering, is a good time for newcomers to give meteor observing a try.

   The Perseids are noted for their abundance of bright events in the photographic range (magnitude 0 and brighter). Perseids - and other bright meteors - can be caught on film using undriven time exposures of 10-15 minutes' duration at f/2.8 or faster with a 50 mm or wide-angle 28 mm lens and ISO 400 film. Some observers have also enjoyed success using series of 30-second exposures on faster digital SLRs. Good aiming directions for photography are towards Cygnus/Summer Triangle early in the night, and the Square of Pegasus in the post-midnight hours.

    Observational reports will, as always, be welcomed by the Meteor Section soon after the shower's end - rates fall off sharply after maximum, and activity is essentially over by August 20 (by which time the Moon will, in any case, be too intrusive to allow effective watches). Hopefully the forecast favourable weather will allow good observational opportunities for the 2005 Perseids after last year's washout, and ahead of the Moon-blighted 2006 return!

Neil Bone

Director, BAA Meteor Section

2005 August 8