Ordinary Meeting, 2002 November 30

Leonid Feedback

Mr Bone had received floods of observation reports since the shower of November 19. Weather had proved problematic for many observers, although those in Scotland and on the Chilterns had had a good view. In other areas, cloud and fog had hindered any form of observation. Preliminary reports suggested that the near-full Moon had limited observers to mag 4 at best.

Referring back to the Asher-McNaught models outlined in his preview at the previous meeting, the speaker suggested that the estimated 3h56 UT peak had come a little later than expected, just after 4h. Mr Bone pointed out that a 10-15 minute error in such predictions was to be expected, and they remain very accurate. At maximum, rates of around 15 meteors per minute had been reported. On average the meteors had been brighter than usual, although there had not been a significant excess of fireballs. One such event at 4h09 had caught the attention of a number of observers, however, and was reported to have left a 20-30 second trail.

Relatively few observations had been received for the 3h region of the distribution, although it appeared that rates had soared at around 3h45 before peaking at 1500 EZHR. On the tail of the distribution, rates had remained high at 4h30, and had reduced to 2-3 meteors per minute by 5h.

The speaker urged observers to take a look at the Geminid shower on December 14, which he believed to be the next best shower after the Leonids. The peak would be at 4h UT, although observation from 1h until dawn was recommended. Mr Bone believed that a good show would be guaranteed, since the shower had frequently reached 120 EZHR in recent years. It was undergoing a period of evolution, and good rates were to be expected for the next decade or so. Early morning observations were likely to be the most fruitful on this occasion due to the late-setting Moon.

Looking further ahead, the speaker also recommended observation of the Quadrantids, due to peak on the night of 2003 January 3-4. The radiant would be low at peak, although the activity might outstrip even the Perseids.

Following the applause for Mr Bone's thorough summary, the President welcomed Mr Jerry Workman to report on the progress of the Cassini mission to Saturn.