[Prev][Next][Index][Thread]
Re: (meteorobs) SURPRISE METEOR SHOWER: the Ursids
Woops, I sent that to meteorobs rather than to Robert Hass.
The Jennisken's study of the alpha Monocerotids was certainly important
and accurate. The point I would make is that without the detailed
physical theory to "explain" the situation, there are necessarily
assumptions that cannot be examined. In the case of the Reznikov
predictions for the Giacobinids and Leonids and those by the American
chap (dang, forgot his name) for the Leonids, that Joe Rao drew attention
to, the calculations were of a very different nature. As with the
Jenniskens-Lyytinen calculations for the Ursids, these calculations
are of a much more detailed form. It was such calculations that I thought
the initial comments were directed at especially as Peter Jenniskens
was part of the discussion. If a more open interpretation is made of what
was being discussed, as Robert assumed, then the answer is that the 1866
Leonids were the first meteor outburst to be predicted.
Given that the calculations for the Ursids are probably accurate, I
would expect activity to occur. If nothing special were to happen
however, this would NOT necessarily mean that the calculations were
faulty. If the comet nucleus is inactive at any specific return, the
dust production could stop and thus certain trails could be "empty". In
the case of the Leonids, dust production could be inferred from the
comet's observed activity at specific returns, or from earlier encounters
with specific dust trails. This luxury does not exist for the perihelion
of P/Tempel responsible for this year's Ursid encounter.
The next day will be an exciting wait!
Cheers, Rob
Robert H. McNaught
rmn@aaocbn.aaodot gov.au
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
References: