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| IMCCE Meteor Shower Ephemerides Server | |
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2007 Alpha-Aurigidsby J. Vaubaillon (IMCCE/CALTECH), in collaboration with P. Jenniskens (SETI Institute, NASA/AMES)Introduction:The (alpha)-Aurigids is a quiet meteor shower, with an annual ZHR of ~10/hr. However on several (and rare) occasions they have displayed a particular outburst (1935, 1986, 1994).P. Jenniskens and E. Lyytinen were the first at predicting that an outburst could happen again in 2007 (see this paper). In collaboration with P. Jenniskens we investigated the evolution of this long period stream. The parent body is comet C/1911 N1 Kiess, which long orbital period is poorly constrained. Taking the initial condition priovided by JPL/HORIZONS for its last return in 1911, and integrating back the comet we found a return in 82BC. Joe Rao (S&T) pointed out to us that no comet was reported in this date. Needless to say that we can be a few years off, but for our concern it does not really matter. The point is that this passage allowed us to look at the location of the 1-revolution trail in the vicinity of the Earth for the XXth and XXIst century. ResultsNEW: ANIMATION OF THE 1-REVOLUTION trailWe were first able to post-predict the outbursts in 1935, 1986 and 1994 For 2007 the conditions are very similar:The date of the maximum was computed as:
E. Lyytinen pointed out that these post/predictions are ~15min. late compared to past observations, so for 2007 he expects the maximum to occur sooner, around 11:20 UT. For the level, I personnally think that ZHR~100 will be reached AT BEST, but some colleagues are more optimistic, so, suspense, suspense!!! P. Jenniskens pointed out that the interest of this shower resides in the fact that we will see dust particles from the pristine layer of the comet (because it is a long period comet). This kind of opportunity is indeed very rare: see the Working list of Meteor outbursts from long-period comet dust trails, by E. Lyytinen and P. Jenniskens. Conclusion: The outburst will be visible form the West coast of the US: be there, do observe and send your report to IMO!!! Observation CampaignExceptional events deserve exceptional efforts. In consequence P. Jenniskens is organizing an international airborne + ground based observing campaign. IMCCE will participate with high sensitivity cameras. More details at the SETI Institute Aurigids website.Results of the observation campaignThe whole team composed of astronomers from the whole world successfully observed the meteor shower! This is very encouraging for the whole scientific community. It helps us to understand not only what a meteor shower is, but also our Solar System and the composition of comets in general. This is the most spectacular observation of a forecasted shower since the Leonids 2002, and the first dealing with a long period comet! We are greatful in particular to Peter Jenniskens (SETI Insitute) and every participant to the expedition, in the air or on the ground. Additional details can be found at the SETI Institute / NASA website. Below is a composite picture of Aurigids meteors, as seen from the plane, at an altitude of 47000 feet.
See alsoPeter Jenniskens web pages (SETI Institute) J. Rao, 2007, Watch for the Aurigids meteors, S&T E. Lyytinen, P. Jenniskens, 2003, Meteor outbursts from long-period comet dust trails Predictions by M. Sato (Japan) |