Saturday, 23 October 2010

November 2010

Propagation Summary
Conditions have remained fairly steady during October. The solar Flux actually reached 90 on the 20th, but it should fall to 75 by November 1st then rise again to 85 by mid November. The Boulder A index should stay at 5 and the K index at 2 during the first half of November. So far during 2010, there have been 45 spotless days (15%) , compared 260 in 2009 (71%). http://www.wm7d.net/hamradio/solar/27d_forecast.shtml )

Meteor Showers
Earth is passing through a stream of debris from Halley's Comet, and this is causing the annual Orionid meteor shower. Bright moonlight is reducing the number of visible meteors; nevertheless, sky watchers are reporting some bright Orionids.
Meteor showers provide a very significant increase in the number of meteor trails that can be used for radio communications. These showers arrive at fixed times of the year, appearing on an annual basis. Some are small, whereas others are much larger and can last for several days. There are hundreds or possibly even thousands of these showers. The smaller showers are not easy to distinguish, but some of the larger showers produce a spectacular display if their occurrence coincides with a clear night.
When a meteor shower is observed it will be seen that the meteors appear to come from a single point in the sky which is known as the "radiant". This is a perspective effect caused by the fact that all the particles enter the Earth's atmosphere parallel to one another. The radiant gives rise to the name of the shower - the Perseids shower has its radiant in the constellation of Perseus.
Showers are caused by groups of particles orbiting the Sun in an elliptical orbit. Usually they are associated with comets which leave their debris behind them. Although not all meteor showers have been linked to particular comets, it is thought that all showers come from this source.
Showers vary in intensity from one year to the next. This happens because the particles are not evenly spread around their orbit. One of the most reliable and constant showers is the Perseids shower, but even this one shows some significant variations from one year to the next.
Meteor showers forecast for November are:
Taurids from 25 October to 25 November peaking on November 4th. Leonids: 15 - 19 November peaking on the 17th. Cephids 7 - 9 November peaking on the 11th More details at: http://surf.to/meteorscatter See also: http://stardate.org/nightsky/meteors and: www.spaceweather.com (Via Mike Terry)

DX Info Centre
Here is a website all about FM and UHF DX’ing. Subjects covered included are Tropospheric Ducting and E Skip. There are also many world maps showing colour coded event forecasts, plus links to other relevant websites: www.dxinfocentre.com/

Links to these articles and more can be found at: www.jameswelsh.org.uk

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