The Lyrids meteor shower: A historical perspective

The April Lyrid meteor shower is the oldest meteor shower ever recorded continuously throughout history, dating as far back as 687 BC. Before the 20th century, historical sources only provided reports of two years of strong activity and up to nine possible additional events. Currently, the shower has low activity, but it has had significant episodes that, during the 20th century, seem to repeat at time intervals that are multiples of 12yr or 60 yr. Earlier outbursts may have also occurred with a frequency consistent with this period. Outbursts of activity are also known in other meteor showers. The classical explanation that they are correlated to the close proximity of the parent comet to the Earth was proven wrong in the last years of the 20th century and this is also clear in the case of the April Lyrids, whose parent comet is C/1861 G1 (Thatcher), with an orbital period of about 400 yr. Our previous research has led us to compile an additional list of possible April Lyrids in the last 2000 years. This paper has two objectives. First, to present the list of possible Lyrids that we have compiled that would significantly increase the number of historical observations considered to date. Secondly, to study if the historical data fit well with the main theories and recent studies concerning the Lyrids.