Discoveries from Observations and Modeling of the 1998/99 Leonids

Jenniskens, Peter

doi:10.1007/978-3-642-56428-4_5

Cited by 10 publications

(12 citation statements)

References 76 publications

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“…The recent Leonid meteor storm of 1999 November 18 and a second outburst half a day later were caused by ejecta from Comet 55P/Tempel-Tuttle released at the returns of 1899 and 1866, respectively (Kondrat'eva and Reznikov 1985, Lyytinen 1999, McNaught and Asher 1999. And three calculated encounters with dust from the 1932, 1733, and 1866 returns were observed much as predicted (Jenniskens 2001a). Similar identifications for short-period comets have been made for outbursts of the June Bootids, Beilids, and Draconids (Reznikov 1983).…”

Section: Introductionsupporting

confidence: 78%

Dust Trails of 8P/Tuttle and the Unusual Outbursts of the Ursid Shower

Jenniskens¹,

Lyytinen²,

Lignie

et al. 2002

Icarus

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We calculate the position of dust trails from comet 8P/Tuttle, in an effort to explain unusual Ursid meteor shower outbursts that were seen when the comet was near aphelion. Comet 8P/Tuttle is a Halley-type comet in a 13.6-year orbit, passing just outside of Earth's orbit. We find that the meteoroids tend to be trapped in the 12:14 mean motion resonance with Jupiter, while the comet librates in a slightly shorter period orbit around the 13:15 resonance. It takes 6 centuries to decrease the perihelion of the meteoroid orbits enough to intersect Earth's orbit, during which time the meteoroids and comet separate in mean anomaly by 6 years, thus explaining the 6-year lag between the comet's return and Ursid outbursts. The resonances also prevent dispersion along the comet orbit and limit viewing to only one year in each return. We identified past dust trail encounters with dust trails from 1392 (Dec. 1945) and 1378 (Dec. 1986) and predicted another outburst on 2000 December 22 at around 7:29 and 8:35 UT, respectively, from dust trails dating to the 1405 and 1392 returns. This event was observed from California using video and photographic techniques. At the same time, five Global-MS-Net stations in Finland, Japan, and Belgium counted meteors using forward meteor scatter. The outburst peaked at 8:06 ± 07 UT, December 22, at zenith hourly rate ∼90 per hour, and the Ursid rates were above half peak intensity during 4.

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Section: Introductionsupporting

confidence: 78%

Dust Trails of 8P/Tuttle and the Unusual Outbursts of the Ursid Shower

Jenniskens¹,

Lyytinen²,

Lignie

et al. 2002

Icarus

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“…To make the resulting trajectory solution averages per shower have realistic weighted geometries given the station locations, activity profiles for each shower are required. The activity profile of simulated meteor showers is defined by the solar longitude of the peak λ max and the slope of the activity profile B, where the activity is approximated as Z HR = Z HR max 10 −B |λ −λ ma x | following Jenniskens (1994).…”

Section: Simulating Radiants and Activitymentioning

confidence: 99%

Estimating trajectories of meteors: an observational Monte Carlo approach – I. Theory

Vida

Gural

Brown

et al. 2019

Monthly Notices of the Royal Astronomical Society

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It has recently been shown by Egal et al. (2017) that some types of existing meteor in-atmosphere trajectory estimation methods may be less accurate than others, particularly when applied to high precision optical measurements. The comparative performance of trajectory solution methods has previously only been examined for a small number of cases. Besides the radiant, orbital accuracy depends on the estimation of pre-atmosphere velocities, which have both random and systematic biases. Thus it is critical to understand the uncertainty in velocity measurement inherent to each trajectory estimation method.In this first of a series of two papers, we introduce a novel meteor trajectory estimation method which uses the observed dynamics of meteors across stations as a global optimization function and which does not require either a theoretical or empirical flight model to solve for velocity. We also develop a 3D observational meteor trajectory simulator that uses a meteor ablation model to replicate the dynamics of meteoroid flight, as a means to validate different trajectory solvers.We both test this new method and compare it to other methods, using synthetic meteors from three major showers spanning a wide range of velocities and geometries (Draconids, Geminids, Perseids). We determine which meteor trajectory solving algorithm performs better for: all-sky, moderate field of view, and high-precision narrowfield optical meteor detection systems. The results are presented in the second paper in this series. Finally, we give detailed equations for estimating meteor trajectories and analytically computing meteoroid orbits, and provide the Python code of the methodology as open source software.

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“…These were modified from the original so that they are centered around the peak solar longitude while the radiant spread was computed directly from data provided in Spurnỳ et al (2017). λ ma x is the solar longitude of the peak (degrees), B is the solar longitude slope of the rising portion of the activity profile following the procedure of Jenniskens (1994), α is the mean geocentric right ascension, ∆α is the radiant drift (degree on the sky per degree of solar longitude), α σ is the standard deviation in R.A., δ is the mean geocentric declination, ∆δ is the declination radiant drift, δ σ is the standard deviation of the declination, V g is the mean geocentric velocity in km s −1 , ∆V g is the change in geocentric velocity per degree of solar longitude, and V gσ is the standard deviation of the geocentric velocity.…”

Section: Resultsmentioning

confidence: 99%

“…As both the Geminids and Perseids are older showers, we do not expect the physical radiant dispersion to be as compact as the Draconids, thus for simulation purposes we have used observed values for these quantities provided in Jenniskens et al (2016) and Jenniskens (1994). We summarize the modeling parameters adopted of the simulated meteors showers in table 2 and the physical properties of shower meteoroids used in the ablation modeling in table 3.…”

Section: Dynamical Modelling Of the 2011 Draconid Outburstmentioning

confidence: 99%

Estimating trajectories of meteors: an observational Monte Carlo approach – II. Results

Vida

Brown

Campbell-Brown

et al. 2019

Monthly Notices of the Royal Astronomical Society

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In the first paper of this series we examined existing methods of optical meteor trajectory estimation and developed a novel method which simultaneously uses both the geometry and the dynamics of meteors to constrain their trajectories. We also developed a simulator which uses an ablation model to generate realistic synthetic meteor trajectories which we use to test meteor trajectory solvers. In this second paper, we perform simulation validation to estimate radiant and velocity accuracy which may be achieved by various meteor observation systems as applied to several meteor showers.For low-resolution all-sky systems, where the meteor deceleration is generally not measurable, the multi-parameter fit method assuming a constant velocity better reproduces the radiant and speed of synthetic meteors. For moderate field of view systems, our novel method performs the best at all convergence angles, while multi-parameter fit methods generally produce larger speed errors. For high-resolution, narrow field of view systems, we find our new method of trajectory estimation reproduces radiant and speed more accurately than all other methods tested. The ablation properties of meteoroids are commonly found to be the limiting factor in velocity accuracy.We show that the true radiant dispersion of meteor showers can be reliably measured with moderate field of view (or more precise) systems provided appropriate methods of meteor trajectory estimation are employed. Finally, we compare estimated and real angular radiant uncertainty and show that for the solvers tested the real radiant error is on average underestimated by a factor of two.

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Discoveries from Observations and Modeling of the 1998/99 Leonids

Cited by 10 publications

References 76 publications

Dust Trails of 8P/Tuttle and the Unusual Outbursts of the Ursid Shower

Dust Trails of 8P/Tuttle and the Unusual Outbursts of the Ursid Shower

Estimating trajectories of meteors: an observational Monte Carlo approach – I. Theory

Estimating trajectories of meteors: an observational Monte Carlo approach – II. Results

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