Abstract:Context. Several authors predicted an outburst of the Draconid meteor shower in 2018, but with an uncertain level of activity. Aims. Optical meteor observations were used to derive the population and mass indices, flux, and radiant positions of Draconid meteors. Methods. 90 minutes of multi-station observations after the predicted peak of activity were performed using highly sensitive Electron Multiplying Charge Coupled Device (EMCCD) cameras. The data calibration is discussed in detail. A novel maximum likeli… Show more
“…From atmospheric observations (Vojáček et al 2019;Vida et al 2020b) and in-situ measurements of dust at parent comets (Fulle et al 2016), it is known that masses of shower meteors are usually distributed according to a power-law distribution:…”
Section: Scaling the Flux To A Target Limiting Magnitude Or Massmentioning
Meteor showers and their outbursts are the dominant source of meteoroid impact risk to spacecraft on short time scales. Meteor shower prediction models depend on historical observations to produce accurate forecasts. However, the current lack of quality and persistent world-wide monitoring at optical meteoroid sizes has left some recent major outbursts poorly observed. A novel method of computing meteor shower flux is developed and applied to Global Meteor Network data. The method is verified against previously published observations of the Perseids and the Geminids. The complete mathematical and algorithmic details of computing meteor shower fluxes from video observations are described. As an example application of our approach, the flux measurements of the 2021 Perseid outburst, the 2020-2022 Quadrantids, and 2020-2021 Geminids are presented. The flux of the 2021 Perseids reached similar levels to the 1991-1994 and 2016 outbursts (ZHR ∼ 280). The flux of the Quadrantids shows high year-to-year variability in the core of the stream while the longer lasting background activity is less variable, consistent with an age difference between the two components. The Geminids show a double peak in flux near the time of peak.
“…From atmospheric observations (Vojáček et al 2019;Vida et al 2020b) and in-situ measurements of dust at parent comets (Fulle et al 2016), it is known that masses of shower meteors are usually distributed according to a power-law distribution:…”
Section: Scaling the Flux To A Target Limiting Magnitude Or Massmentioning
Meteor showers and their outbursts are the dominant source of meteoroid impact risk to spacecraft on short time scales. Meteor shower prediction models depend on historical observations to produce accurate forecasts. However, the current lack of quality and persistent world-wide monitoring at optical meteoroid sizes has left some recent major outbursts poorly observed. A novel method of computing meteor shower flux is developed and applied to Global Meteor Network data. The method is verified against previously published observations of the Perseids and the Geminids. The complete mathematical and algorithmic details of computing meteor shower fluxes from video observations are described. As an example application of our approach, the flux measurements of the 2021 Perseid outburst, the 2020-2022 Quadrantids, and 2020-2021 Geminids are presented. The flux of the 2021 Perseids reached similar levels to the 1991-1994 and 2016 outbursts (ZHR ∼ 280). The flux of the Quadrantids shows high year-to-year variability in the core of the stream while the longer lasting background activity is less variable, consistent with an age difference between the two components. The Geminids show a double peak in flux near the time of peak.
“…The cameras begin to show saturation effects near meteor magnitudes of +1. For example meteor images and more details about the system see Vida et al (2020).…”
Section: Optical Camerasmentioning
confidence: 99%
“…Distribution of peak magnitudes for iron (red) and the entire population as a whole. The effective survey completeness is to an absolute magnitude of +6 at low speeds using the methodology described in(Vida et al 2020), falling to +5 at 60 km/s.…”
We report results of a four-year survey using Electron Multiplied Charged Coupled Device (EMCCD) cameras recording 34761 two-station video meteor events complete to a limiting magnitude of +6. The survey goal was to characterize probable iron meteoroids. Using only physical properties of the meteor trajectories including early peaking light curves, short luminous trajectories, and high energies accumulated per area at beginning, we identified 1068 iron meteors. Our iron candidates are most abundant at slow speeds < 15 km/s, where they make up ≈20% of the mm-sized meteoroid population. They are overwhelmingly on asteroidal orbits, and have particularly low orbital eccentricities and smaller semi-major axes when compared to non-irons between 10-20 km/s. Our iron population appears to be more numerous at fainter magnitudes, comprising 15% of slow (10-15 km/s) meteors with peak brightness of +3 with the fraction rising to 25% at +6 to +7, our survey limit. The iron orbits are most consistent with an asteroidal source and are in highly evolved orbits, suggesting long collisional lifetimes (10 7 years). Metal-rich chondrules (nodules) found in abundance in EL Chondrites are one possible source for this population. We also propose a possible technique using R-band colours to more robustly identify fainter iron meteors with very high confidence.
“…The period covered by our survey (2018-2021) includes several meteor shower outbursts. Unfortunately, the 2018 Draconid outburst (Egal et al 2018;Vida et al 2020c) was only observed from a single station as the network was still in development at the time (Vida et al 2018a). Nevertheless, several other outbursts were recorded; the associated mean radiants and orbital elements are given in Table 2.…”
The Global Meteor Network (GMN) utilizes highly sensitive low-cost CMOS video cameras which run open-source meteor detection software on Raspberry Pi computers. Currently, over 450 GMN cameras in 30 countries are deployed.The main goal of the network is to provide long-term characterization of the radiants, flux, and size distribution of annual meteor showers and outbursts in the optical meteor mass range. The rapid 24-hour publication cycle the orbital data will enhance the public situational awareness of the near-Earth meteoroid environment. The GMN also aims to increase the number of instrumentally observed meteorite falls and the transparency of data reduction methods.A novel astrometry calibration method is presented which allows decoupling of the camera pointing from the distortion, and is used for frequent pointing calibrations through the night. Using wide-field cameras (88°× 48°) with a limiting stellar magnitude of +6.0 ± 0.5 at 25 frames per second, over 220,000 precise meteoroid orbits were collected since December 2018 until June 2021.The median radiant precision of all computed trajectories is 0.47°, 0.32°for ∼ 20% of meteors which were observed from 4+ stations, a precision sufficient to measure physical dispersions of meteor showers. All non-daytime annual established meteor showers were observed during that time, including five outbursts. An analysis of a meteorite-dropping fireball is presented which showed visible wake, fragmentation details, and several discernible fragments. It had spatial trajectory fit errors of only ∼40 m, which translated into the estimated radiant and velocity errors of 3 arc minutes and tens of meters per second.
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