Meteor Showers from the Debris of Broken Comets: D/1819 W1 (Blanpain), 2003 WY25, and the Phoenicids
The discovery of extinct comet nucleus 2003 EH1 in the orbit of the massive Quadrantid meteor shower, and its tentative identification as a fragment of comet C/1490 Y1, is now followed by the discovery that minor planet 2003 WY25 is among the meteoroids causing the Phoenicid shower and may be a remnant of comet D/1819 W1 (Blanpain). Backward integration of 2003 WY25 to 1819 shows agreement in angular elements to 0.2d accuracy, proving the association, with no better agreement expected because of the poorly determined orbit of D/Blanpain. 2003 WY25 is a faint object, suggesting it is only a ~400 m diameter fragment of D/Blanpain, broken up shortly before or during the 1819 return. Forward integration of the perturbations on the dust trail that would be generated in such a breakup shows that this dust accounts for the 1956 outburst of Phoenicids and establishes the link between the meteoroids and the comet. This new result adds further evidence to a new paradigm: that most of our short-period meteor showers are due to the breakup of comets. These showers (and the remaining fragments) include at least the Geminids (3200 Phaethon), the Quadrantids (2003 EH1), the Daytime Arietids (Marsden group of sunskirters), the Andromedids (fragments of 3D/Biela), and now also the Phoenicids (2003 WY25). The amount of mass in each stream is relatively small, that of a single fragment. If comet 9P/Tempel 1 breaks during NASA's Deep Impact mission, a meteoroid stream will be created in much the same manner as what causes most of our meteor showers.