Meteor pairs and groups in Geminid meteor shower

2020 ◽  
Author(s):  
Pavel Koten ◽  
David Čapek

<p>The existence of the pairs and larger groups of the meteors was already investigated in several papers. Recent statistical analyses of radar or optical data on several meteor showers provided rather negative results. Nevertheless, some level of groupings is possible, especially among young streams.</p> <p>When digitalizing older videotapes obtained during the 2006 Geminid campaign, we found a relatively higher number of meteors that appear in pairs. Therefore we investigated this observational result in more detail.</p> <p>Statistically, when observing Geminid meteor shower, we could expect 1.4 randomly paired meteors per 1 hour assuming ZHR = 100 and the maximum gap between meteors of 1 second. There were recorded 9 pairs during 3.5 hours of observation. Therefore at least some of them cannot be statistically random pairs. Moreover, a triplet of meteors detected within 1 second is well above the statistical threshold for random appearance.</p> <p>In this talk, we will provide more detailed analyses of all the cases as well as some possible scenarios of their origin.</p>

1972 ◽  
Vol 45 ◽  
pp. 173-180
Author(s):  
Yu. V. Evdokimov

Orbital elements of P/Giacobini-Zinner have been obtained from 577 observations at the eight apparitions 1900 to 1965 by linking apparitions in pairs. By this technique we established that the comet has a nongravitational secular deceleration amounting, on the average, to 0.081 day/(period)2. As a result of the comet's approach to Jupiter in 1969, a return of the Draconid meteor shower is possible on 1972 October 8d15h45m UT. The 1946 meteor shower was due to meteoroids ejected forward along the orbit of the comet in 1940 with velocities of 14 m s- 1. The meteor showers of 1933 and 1926 were apparently produced by meteoroids ejected in 1900 with velocities of 15.0 m s- 1 forward and 14.5 m s- 1 backward, respectively.


2020 ◽  
Author(s):  
Veronika Barta ◽  
Zbysek Mosna ◽  
Daniel Kouba ◽  
Antal Igaz ◽  
Krisztián Sárneczky

<p>The impact of meteor showers and individual meteors on the ionosphere has been investigated during wintertime meteor showers using synchronised measurements of two DPS-4D Digisondes installed at Pruhonice (50°, 14.5°) and at Sopron (47.63°, 16.72°). Rather short distance between Pruhonice and Sopron allow us to perform special joint campaigns of vertical and oblique sounding under the high sampling rate to detect fine structures within ionospheric plasma.</p><p> </p><p>High cadence campaigns have been performed to observe behavior of sporadic E layer (Es) during the Leonids, Geminids and Quadrantids meteor showers in 2018 and 2019. The time resolution of the ionograms have been set to approximately 0.5 - 2 ionograms per minute. We used vertical and oblique reflections to investigate the fine structure and the movement of Es layer. Based on the first results the oblique sounding is a good technique to detect the Es activity between two stations, however there were periods (typically 10 to 40 minutes of duration) when the Es was observed using oblique trace but there was no observation of Es layer in vertical ionograms. Furthermore, double Es structures have been detected more times for tens of minutes during the observation nights.</p><p> </p><p>Beside the regular behavior of Es we concentrated on observation of intervals of increased plasma frequency in the Es region presumably directly induced by the meteors. In the framework of GINOP-2.3.2-15-2016-00003 (“Kozmikus hatások és kockázatok") an optical camera has been installed at the MTA Széchenyi István Geophysical Observatory (Sopron) in September 2019 with the cooperation of the Konkoly Observatory to monitor the meteors. Therefore, we were able to compare the ionograms measured during meteor showers with the optical data to determine the plasma trails of individual meteors. In the 20-25% of the observed meteors a faint Es layers were detected on the ionograms during and after (< 1 min) the optical record. The direction of the detected plasma traces determined by the SAO Explorer was in good agreement with the direction of the optically observed meteors in most of the cases. Consequently, the plasma trace of individual meteors could be detected on the high time resolution ionograms.</p>


2010 ◽  
Vol 10 (3) ◽  
pp. 909-917 ◽  
Author(s):  
J. Correira ◽  
A. C. Aikin ◽  
J. M. Grebowsky ◽  
J. P. Burrows

Abstract. Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996–2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.


2009 ◽  
Vol 9 (5) ◽  
pp. 18705-18726
Author(s):  
J. Correira ◽  
A. C. Aikin ◽  
J. M. Grebowsky ◽  
J. P. Burrows

Abstract. Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996–2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.


1968 ◽  
Vol 33 ◽  
pp. 352-361
Author(s):  
W. G. Elford

Theoretical hourly rates of radar echoes from meteor showers observed with narrow- and wide-aperture systems are calculated in terms of equipment parameters and the distribution of the number of meteors as a function of mass. From a comparison of the echo rates in selected range intervals, it is shown that it is possible to determine the value of the exponent in a simple inverse power flux law.The effect on the echo rate of a change in the value of the exponent in the flux law with magnitude is described and the probability of detecting showers at different stations is discussed.It is suggested that simple radar echo counts in several range intervals can be used to determine the mass distribution of meteor showers over a range of two or three magnitudes above the limiting magnitude of the system. The analysis is applied to some observations made at Christchurch and Ottawa.


2012 ◽  
Vol 10 (H16) ◽  
pp. 142-142
Author(s):  
Peter Jenniskens

AbstractThe IAU Meteor Shower Working List contains 369 showers, of which only 64 are considered established (per February 28, 2012). In this invited review, we will give an overview of international efforts to validate the remaining showers. We report on the showers that were validated in this triennium and proposed to receive the predicate “established" at the present General Assembly. The meteoroid orbit surveys characterize the meteoroid streams in terms of orbital elements and their dispersions, which is ground truth for efforts to identify their parent comets, study the fragmentation history of the (mostly dormant) comet population in the inner solar system, and understand the origin of the zodiacal cloud.


2006 ◽  
Vol 2 (S236) ◽  
pp. 135-140
Author(s):  
Pulat B. Babadzhanov ◽  
Iwan P. Williams

AbstractThe existence of an observed meteor shower associated with some Near-Earth Asteroid (NEA) is one of the few useful criteria that can be used to indicate that such an object could be a candidate for being regarded as an extinct or dormant cometary nucleus. In order to identify possible new NEA-meteor showers associations, the secular variations of the orbital elements of the NEA 2000 PG3, with comet-like albedo (0.02), and moving on a comet-like orbit, was investigated under the gravitational action of the Sun and six planets (Mercury to Saturn) over one cycle of variation of the argument of perihelion. The theoretical geocentric radiants and velocities of four possible meteor showers associated with this object are determined. Using published data, the theoretically predicted showers were identified with the night-time September Northern and Southern δ-Piscids fireball showers and several fireballs, and with the day-time meteor associations γ-Arietids and α-Piscids. The character of the orbit and low albedo of 2000 PG3, and the existence of observed meteor showers associated with 2000 PG3 provide evidence supporting the conjecture that this object may be of cometary nature.


1965 ◽  
Vol 23 ◽  
pp. 241-244
Author(s):  
Philip C. Fisher ◽  
Dwight B. Clark ◽  
Arthur J. Meyerott ◽  
Kermit L. Smith

Final results are presented for a March 20, 1963 search for night sky sources of soft X-rays. Although one sky region was found to be associated with an X-ray flux 2,5 to 3 standard deviations above background, the probability of observing one random fluctuation of this importance in the data for the night sky is estimated to be as high as 20%. The region is located at α= 23 h 40 m, δ = + 78°. Apparently negative results from a search of the data for variations of X-ray background with galactic latitude are presented and discussed.


2019 ◽  
Vol 629 ◽  
pp. A137 ◽  
Author(s):  
Lukáš Shrbený ◽  
Pavel Spurný

We present 25 photographic fireballs belonging to the September epsilon Perseid (SPE, IAU #208) meteor shower observed by the Czech part of the European Fireball Network in 2013–2017. Exceptional high activity of bright photographic fireballs was observed in 2013, while a lower activity, but still higher than in other years, was observed in the period of 2015–2017. Physical properties of these SPE fireballs were studied and compared to other meteor showers. Perseids are found to be the closest analog to SPE. Corrected geocentric radiant of the 2013 outburst fireballs was determined for solar longitude 167.20° and has right ascension 47.67 ± 0.04° and declination 39.493 ± 0.013° (J2000.0). On the basis of determined heliocentric orbits the parent body of the shower is an unknown long-period comet on retrograde orbit with an orbital period of the order of a thousand years.


2021 ◽  
Author(s):  
Surya Ambardar ◽  
Siddha Ganju ◽  
Peter Jenniskens

<p>Meteor showers are some of the most dazzling and memorable events occuring in the night sky. Caused by bits of celestial debris from comets and asteroids entering Earth’s atmosphere at astronomical speeds, meteors are bright streaks of light in the night sky, sometimes called shooting stars. Those meteors are recorded, tracked and triangulated by low-light surveillance cameras in a project called CAMS: Cameras for Allsky Meteor Surveillance. CAMS offers insights into a universe of otherwise invisible solar system bodies, but that task has proven difficult due to the lack of automated supervision. Until recently, much of the data control was done by hand. Necessary to build supervised classification models,  labeled training data is essential because other man-made objects such as airplanes and satellites can be mistaken for meteors. To address this issue, we leverage one year's worth of meteor activity data from CAMS to provide weak supervision for over a decade of collected data, drastically reducing the amount of manual annotation necessary and expanding available labelled meteor training data.</p><p> </p><p>Founded in 2010, CAMS aims to automate video surveillance of the night sky to validate the International Astronomical Union’s Working List of Meteor Showers, discover new meteor showers, and predict future meteor showers. Since 2010, CAMS has collected a decade's worth of night sky activity data in the form of astrometric tracks and brightness profiles, a year of which has been manually annotated. We utilize this one year's labelled data to train a high confidence LSTM meteor classifier to generate low confidence labels for the remaining decade’s worth of meteor data. Our classifier yields confidence levels for each prediction, and when the confidence lies above a statistically significant threshold, predicted labels can be treated as weak supervision for future training runs. Remaining predictions below the threshold can be manually annotated. Using a high threshold minimizes label noise and ensures instances are correctly labeled while considerably reducing the  amount of data that needs to be annotated. Weak supervision can be confirmed by checking date ranges and data distributions for known meteor showers to verify predicted labels.</p><p> </p><p>To encourage discovery and distribution of training data and models, we additionally provide scripts to automate data ingestion and model training from raw camera data files. The data scripts handle processing of CAMS data, providing a pipeline to encourage open sharing and reproduction of our research. Additionally, we provide code for a LSTM classifier baseline model which can identify probable meteors. This baseline model script allows further exploration of CAMS data and an opportunity to experiment with other model types.  </p><p> </p><p>In conclusion, our contributions are (1) a weak supervision method utilizing a year’s worth of labelled CAMS data to generate labels for a decade’s worth of data, along with (2) baseline data processing and model scripts to encourage open discovery and distribution. Our unique contributions expand access to labeled training meteor data and make the data globally and publicly accessible thorough daily generated maps of meteor shower activity posted at http://cams.seti.org/FDL/. </p>


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