Meteor Data Center Research Articles

Search for duplicates of showers in the IAU MDC database

Context. The meteor shower database of the IAU Meteor Data Center (MDC) is used by the whole community of meteor astronomers. Observers submit both new and known meteor shower parameters to the MDC. Two types of problems may arise during the submission process: If a new observation of an already-known meteor shower is submitted as the discovery of a new shower, a duplicate shower will appear in the MDC. If the submission of a new set of parameters for an existing shower is incorrect, a false duplicate of a known meteor shower will appear in the MDC. The MDC database contains such duplicates and false duplicates, so it is desirable to detect them among the streams already in the database and those delivered to the database as new streams. Aims. We aim to develop a method for objective detection of duplicates among meteor showers and to apply it to the MDC. The method will also enable us to verify whether various sets of parameters of the same shower are compatible and thus reveal the false duplicates. Methods. We suggest two methods based on cluster analyses and two similarity functions among geocentric and heliocentric shower parameters collected in the MDC. Results. We obtained a number of results of varying significance. Seven new showers represented by two or more parameter sets were discovered, revealing the duplicates we searched for. We found full agreement between our results and those reported in the MDC database for 30 showers. The multiple sets of parameters defining these showers are correct since they were identified as duplicates. For 20 showers, the same duplicates as given in the MDC were found only by one method. We found 27 showers for which the number of parameter sets found by both methods is close to the corresponding number in the MDC database. However, we found 56 showers listed in the MDC by more than one set of parameters for which no duplicates were found by either of the applied methods. These showers have false duplicates among their sets of parameters. Conclusions. The obtained results confirm the effectiveness of the proposed approach of identifying duplicates. We have shown that in order to detect and verify duplicate meteor showers, it is possible to apply the objective proposal instead of the subjective approach used so far. We consider the identification of 83 problematic cases in the MDC database, among which at least some duplicates were misclassified, to be a particularly important result. The correction of these cases will significantly improve the content of the MDC database.

Showers with both Northern and Southern solutions

Meteoroids of a low-inclination stream hit the Earth arriving from a direction near the ecliptic. The radiant area of stream like this is often divided into two parts: one is situated northward and the other southward of the ecliptic. In other words, two showers are caused by such a stream. Well-known examples of such showers are the Northern Taurids, #17, and Southern Taurids, #2, or the Northern δ-Aquariids, #26, and Southern δ-Aquariids, #5. While the meteoroids of the northern shower collide with the Earth in the descending node, those of the southern shower collide with our planet in the ascending node of their orbits. Because of this circumstance and tradition, the northern and southern showers must be distinguished. Unfortunately, this is not always the case with meteor showers listed in the IAU Meteor Data Center (MDC). For the same shower, some authors reported a set of its mean parameters corresponding to the northern shower and other authors to the southern shower. We found eleven such cases in the MDC. In this paper, we propose corrections of these mis-identifications.

Modification of the Shower Database of the IAU Meteor Data Center

Context. The Shower Database (SD) of the Meteor Data Center (MDC) has been operating for 15 yr and is used by the entire community of meteor astronomers. It contains meteor showers categorised in individual lists on the basis of their status. Since the inception of the SD, no objective rules for moving showers between individual lists have been established. The content of the SD has not yet been checked for the correctness of the meteor data contained therein. Aims. Our aims are (1) to formulate criteria for nominating meteor showers for established status, (2) to improve the rules for the removal of showers, (3) to verify and enhance the content of the SD, and (4) to improve the user area of the MDC SD. Methods. The criteria for moving showers from the Working list to the Lists of established or removed showers were generated using an empirical evaluation of their impact on the registered showers. The correctness of the parameters of each stream included in the SD was checked by comparing them with the values given in the source publications. Results. We developed a set of criteria for nominating showers to be established. We objectified rules for the temporary and permanent removal of meteor showers from the Working list. Both of our proposed new procedures were approved by a vote of the commission F1 of the IAU in July 2022. We verified more than 1350 data records of the MDC SD and introduced ~1700 corrections. We included new parameters for shower characterisation. As a result of our verification procedure, 117 showers have been moved to the List of removed showers. As of October 2022, the SD contains 923 showers, 110 of which are in the List of established showers and 813 are in the Working list. We also improved the user area of the SD and added a simple tool to allow a quick check of the similarity of a new shower to those in the database.

The κ-Cygnid Meteor Shower and Its Relationship with Near-Earth Asteroids

This study is focused on the relationships between the κ-Cygnid meteor shower and different groups of asteroids crossing the Earth’s orbit (the so-called near-Earth objects (NEOs)). The analysis is based on the visible structure of the meteor shower and a comprehensive strategy for estimating the proximity of orbits of two bodies. The κ-Cygnid meteor shower (abbreviated as KCG) is observed from August 3 to August 25 every year; it is classified as a minor shower, and the size of its mean orbit is around 3.2 AU, while the geocentric velocity is 20.9 km/s. No parent body (PB) of the shower has been found among comets so far. Relationships between the shower and asteroids, as potential PBs of the shower, are under active examination; some hypotheses on this subject can be found on the website of the Meteor Data Center (MDC) of the International Astronomical Union (IAU).

Orbital evolution of meteorite-producing groups and their sources

This paper presents and discusses findings from the study of orbital evolution of six meteorite-producing groups, which include meteorites known from instrumental observations. The existence of four meteorite-producing groups was studied earlier by Halliday et al. using data from the Meteorite Observation and Recovery Project (MORP) network in Canada and the Prairie Network (PN) in USA. We have inferred the asteroidal origin of some fireball streams. Shestaka investigated a swarm of meteorite-forming bodies containing the Innisfree and Ridgedale fireballs. The study yielded that the examined swarm contained nine small meteoric swarms, several asteroids and 12 fireballs photographed by the cameras of the Prairie Network and Canadian Meteorite Observation and Recovery Project. The investigation of the annual activity profile of bright sporadic fireballs from the International Astronomical Union Meteor Data Centre (IAU MDC) database and small meteors (from -2.5 to -5.0 mag) from the SonataCo database resulted in the identification of several peaks in the fireball activity which were not related to any recognised cometary meteor showers. Such results gave an impetus to further study the issue of the existence of groups of sporadic meteoroids and L3.5-H5 ordinary chondrites in Jupiter-family comet-like orbits in the near-Earth space and their relationship with their plausible parents, i.e. near-Earth objects (NEOs). The relationship between meteorite-producing groups and their plausible parents was verified by the backwards analysis of the evolution of the mean orbit of each meteorite-producing group, a known meteorite and their plausible parent NEOs over a time span of several millennia. The analysis was carried out using the Halley software whereby the equations of motion were numerically integrated using the 11th-order Everhart method.

October Draconids 2018 outburst by AMOS

The analysis of Slovak Video Meteor Network (SVMN) observation of October Draconids (009/DRA in the IAU Meteor Data Center) meteor shower on Oct. 8, 2018, is presented. Three all-sky AMOS cameras were in operation during short-lived display of October Draconids. Over hundred shower meteors are recorded within the outburst by single station. We derived ZHR counts for two stations in suitable time intervals. They reveal almost the same behaviour of the activity, in details. Overall it can be accounted to rather fine complex structure of the recent October Draconids stream. Hereby we can identify at least three peaks in the count of shower meteors, on a short time scale. 25 double-station and one multi-station orbits of the shower meteors gathered within the SVMN are analysed and radiant position and area is derived. The results will be compared with data published of Draconids (2011), 2012 outbursts.

Selected catalog of highly eccentric orbits of meteoroids from archived data of radio observations of faint meteors in Kharkiv, Ukraine

Full Kharkiv archival data from 1972 to 1978 have a volume of almost 250 thousand meteor orbits. Of these, we used a sample of sporadic meteoroids with a volume of 159319 orbits. We selected 214 meteor orbits with the aphelia exceeding 100 AU. The greatest aphelion distance for them was 1997.7 (near 2000) AU. At the same time, meteoroids in these orbits invaded the Earth’s atmosphere and burned, creating ionized meteor tracks. The sensitivity of the Kharkiv orbital radar made it possible to record radio meteors up to +12 ​M from meteoroids in the mass range 10−3-10−6 g. Thus, the selected catalog of 214 meteor orbits represents a kind of toolkit for testing remote areas of the Solar system associated with objects called sednoids. The selected catalog of 214 highly eccentric orbits of weak radio meteors up to +12 ​M is presented in the form of tables with a description of the data. Distributions by various parameters for 214 orbits and 159319 orbits are given.The mapping of the annual cycle of observations may be obtained across a catalog of 6743 sporadic meteor orbits, which were published by Voloshchuk, Kolomiyets, and Cherkas in 2018. It is planned to transfer the Kharkiv archived meteor radar data to the IAU Meteor Data Center using experience of transferring archived data of radio observations of past years, received at the Hissar Observatory in Tajikistan which was published by Narziev in 2018.

Long-period comet C/1963 A1 (Ikeya), the probable parent body of π-Hydrids, δ-Corvids, November α-Sextantids, and ϑ-Leonids

Aims. We study the meteoroid stream of the long-period comet C/1963 A1 (Ikeya) to predict the meteor showers originating in this comet. We also aim to identify the predicted showers with their real counterparts. Methods. We modeled 23 parts of a theoretical meteoroid stream of the parent comet considered. Each of our models is characterized by a single value of the evolutionary time and a single value of the strength of the Poynting–Robertson effect. The evolutionary time is defined as the time before the present when the stream is modeled and when we start to follow its dynamical evolution. This period ranges from 10 000 to 80 000 yr. In each model, we considered a stream consisting of 10 000 test particles that dynamically evolve, and their dynamics is followed via a numerical integration up to the present. At the end of the integration, we analyzed the mean orbital characteristics of particles in the orbits approaching Earth’s orbit, which thus enabled us to predict a shower related to the parent comet. We attempted to identify each predicted shower with a shower recorded in the International Astronomical Union Meteor Data Center list of all showers. In addition, we tried to separate, often successfully, a real counterpart of each predicted shower from the databases of real meteors. Results. Many modeled parts of the stream of comet C/1963 A1 are identified with the corresponding real showers in three video-meteor databases. No real counterpart is found in the IAU MDC photographic or radio-meteor data. Specifically, we predict five showers related to C/1963 A1. Two predicted showers are identified with π-Hydrids #101 and δ-Corvids #729. The third predicted shower is only vaguely similar to November α-Sextantids #483, when its mean orbit is compared with the mean orbit of the November α-Sextantids in the IAU MDC list of all showers. However, the prediction is very consistent with the corresponding showers newly separated from three video databases. Another predicted shower has no counterpart in the IAU MDC list, but there is a good match of the prediction and a shower that we separated from the Cameras for Allsky Meteor Surveillance video data. We name this new shower ϑ-Leonids. The last of the predicted showers should be relatively low in number and, hence, no real counterparts were either found in the IAU MDC list or separated from any considered database.

Modeling of the meteoroid stream of comet C/1975 T2 and λ-Ursae Majorids

Aims. We study the meteoroid stream of the long-period comet C/1975 T2 (Suzuki-Saigusa-Mori). This comet was suggested as the parent body of the established λ-Ursae Majorid meteor shower, No. 524. Methods. We modeled 32 parts of a theoretical meteoroid stream of the parent comet considered. Each of our models is characterized with a single value of the evolutionary time and a single value of the strength of Poynting-Robertson effect. The evolutionary time ranges from 10 000 to 80 000 yr. It is the period during which the evolution of the stream part is followed. In each model, the dynamical evolution of 10 000 test particles was then followed, via a numerical integration, from the time of the modeling up to the present. At the end of the integration, we analyzed the mean orbital characteristics of particles in the orbits that approach the Earth’s orbit, which thus enabled us to predict a shower related to the parent comet. The predicted shower was subsequently compared with its observed counterparts. We separated the latter from the databases of real meteors. As well, we attempted to identify the predicted shower to a shower recorded in the International Astronomical Union Meteor Data Center (IAU MDC) list of all showers. Results. Almost all modeled parts of the stream of comet C/1975 T2 are identified with the corresponding real shower in three video-meteor databases. No real counterpart is found in the IAU MDC photographic or radio-meteor data. In the IAU MDC list of showers and in our current study, this shower is identified with the established λ-Ursae Majorid shower, No. 524. Hence, our modeling confirms the results of previous authors. At the same time we exclude an existence of other meteor shower associated with C/1975 T2.

Association between meteor showers and asteroids using multivariate criteria

Context. Meteoroid streams are fragments of matter produced by comets or asteroids which intersects the orbit of Earth. Meteor showers are produced when Earth intersects these streams of matter. The discoveries of active asteroids and extinct comets open a new view of the relation between these objects as possible parent bodies at the origin of meteor showers. Aims. The aim of this work is to identify the asteroids that can produce or re-populate meteoroid streams by determining the similarity of their orbits and orbital evolution over 10 000 yr.Methods. The identification was carried out by evaluating several well known D -criteria metrics, the orbits being taken from the IAU Meteor Data Center database and from IAU Minor Planet Center. Finally, we analyzed the physical properties and the orbital stability (in the Lyapunov time sense) of the candidates as well as their possible relationship with meteorites.Results. 206 near-Earth asteroids (NEAs) were associated as possible parent bodies with 28 meteor showers, according to at least two of the criterion used. 50 of them satisfied all the criteria. Notable finds are: binary asteroid 2000UG11 associated with Andromedids (AND), while the tumbling asteroid (4179)Toutatis could be associated with October Capricornids (OCC). Other possible good candidates are 2004TG10, 2008EY5, 2010CF55, 2010TU149 and 2014OY1. These objects have low albedo, therefore can be primitive objects. Asteroid 2007LW19 which is a fast rotator and most probably has monolithic structure and so its physical characteristic does not support the association found based on the dynamical criteria.

Regular and transitory showers of comet C/1979 Y1 (Bradfield)

Aims. We intend to map the whole meteor complex of the long-period comet C/1979 Y1 (Bradfield), which is a proposed parent body of the July Pegasids, No. 175 in the list of meteor showers established by the Meteor Data Center (MDC) of the International Astronomical Union (IAU).Methods. For five perihelion passages of the parent comet in the past, we model associated theoretical stream, its parts, each consisting of 10 000 test particles, and follow the dynamical evolution of these parts up to the present. Subsequently, we analyze the mean orbital characteristics of those particles of the parts that approach the Earth’s orbit and, thus, create a shower or showers. The showers are compared with their observed counterparts separated from photographic, radio, and several video databases.Results. The modeled stream of C/1979 Y1 approaches the Earth’s orbit in two filaments that correspond to two regular (annual) showers. We confirm the generic relationship between the studied parent comet and 175 July Pegasids. The other predicted shower is a daytime shower with the mean radiant situated symmetrically to the July Pegasids with respect to the apex of the Earth’s motion. This shower is not in the IAU MDC list, but we separated it from the Cameras-for-Allsky-Meteor-Surveillance (CAMS) and SonotaCo video data as a new shower. We suggest naming it α -Microscopiids. The stronger influence of the Poynting-Robertson drag deflects the stream away from the Earth’s orbit in those sections that correspond to the July Pegasids and the predicted daytime shower, but it makes the stream cross the Earth’s orbit in other sections. Corresponding showers are, however, only expected to survive during a limited period and to consist of particles of sizes in a narrow interval. We identified one of these “transitory” filaments to the 104 γ -Bootids in the IAU MDC list of meteor showers.

IAU Meteor Data Center—the shower database: A status report

Currently, the meteor shower part of Meteor Data Center database includes: 112 established showers, 563 in the working list, among them 36 have the pro tempore status. The list of shower complexes contains 25 groups, 3 have established status and 1 has the pro tempore status.In the past three years, new meteor showers submitted to the MDC database were detected amongst the meteors observed by CAMS stations (Cameras for Allsky Meteor Surveillance), those included in the EDMOND (European viDeo MeteOr Network Database), those collected by the Japanese SonotaCo Network, recorded in the IMO (International Meteor Organization) database, observed by the Croatian Meteor Network and on the Southern Hemisphere by the SAAMER radar.At the XXIX General Assembly of the IAU in Honolulu, Hawaii in 2015, the names of 18 showers were officially accepted and moved to the list of established ones. Also, one shower already officially named (3/SIA the Southern iota Aquariids) was moved back to the working list of meteor showers. At the XXIX GA IAU the basic shower nomenclature rule was modified, the new formulation predicates “The general rule is that a meteor shower (and a meteoroid stream) should be named after the constellation that contains the nearest star to the radiant point, using the possessive Latin form”.Over the last three years the MDC database was supplemented with the earlier published original data on meteor showers, which permitted verification of the correctness of the MDC data and extension of bibliographic information. Slowly but surely new database software options are implemented, and software bugs are corrected.

CAMS newly detected meteor showers and the sporadic background

The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit survey adds 60 newly identified showers to the IAU Working List of Meteor Showers (numbers 427, 445–446, 506–507, and part of 643–750). 28 of these are also detected in the independent SonotaCo survey. In total, 230 meteor showers and shower components are identified in CAMS data, 177 of which are detected in at least two independent surveys. From the power-law size frequency distribution of detected showers, we extrapolate that 36% of all CAMS-observed meteors originated from ∼700 showers above the N=1 per 110,000 shower limit. 71% of mass falling to Earth from streams arrives on Jupiter-family type orbits. The transient Geminids account for another 15%. All meteoroids not assigned to streams form a sporadic background with highest detected numbers from the apex source, but with 98% of mass falling in from the antihelion source. Even at large ∼7-mm sizes, a Poynting–Robertson drag evolved population is detected, which implies that the Grün et al. collisional lifetimes at these sizes are underestimated by about a factor of 10. While these large grains survive collisions, many fade on a 104-y timescale, possibly because they disintegrate into smaller particles by processes other than collisions, leaving a more resilient population to evolve.The meteors assigned to the various showers are identified in the CAMS Meteoroid Orbit Database 2.0 submitted to the IAU Meteor Data Center, and can be accessed also at http://cams.seti.org.

Independent identification of meteor showers in EDMOND database

Cooperation and data sharing among national networks and International Meteor Organization Video Meteor Database (IMO VMDB) resulted in European viDeo MeteOr Network Database (EDMOND). The current version of the database (EDMOND 5.0) contains 144 749 orbits collected from 2001 to 2014. This paper presents the results obtained by a proposed new independent method of meteor showers identification, which is applied to the current version of the database (EDMOND 5.0). In the first step of the survey we used the DSH criterion to find groups around each meteor within the similarity threshold. Mean parameters of the groups were calculated and compared using a new function DX based on geocentric parameters (λ⊙, α, δ, and Vg). Similar groups were merged into final clusters (representing meteor showers), and compared with the IAU Meteor Data Center list of meteor showers.

Variation of Meteor Heights and Solar-Cycle Activity

Photographic meteor observations of the Perseid meteoroid stream compiled from the IAU Meteor Data Center catalogue are analyzed from the viewpoint of possible long-term variation of meteor heights with the solar-cycle activity, which was previously reported from radio observations. The observed beginning and end-point heights of the Perseids, normalized for the geocentric velocity and the absolute photographic magnitude, do not show a variation consistent with the solar-cycle activity. This result is valid for the mass range of larger meteoroids observed by photographic techniques, and must be still verified also for the range of smaller meteoroids observed by TV and radio methods.

CAMS: Cameras for Allsky Meteor Surveillance to establish minor meteor showers

First results are presented from a newly developed meteoroid orbit survey, called CAMS – Cameras for Allsky Meteor Surveillance, which combines meteor detection algorithms for low-light video observations with traditional video surveillance tools. Sixty video cameras at three stations monitor the sky above 31° elevation. Goal of CAMS is to verify meteor showers in search of their parent comets among newly discovered near-Earth objects. This paper outlines the concept of operations, the hardware, and software methods used during operation and in the data reduction pipeline, and accompanies the data release of the first batch of meteoroid orbits. During the month of November 2010, 2169 precisely reduced meteoroid trajectories from 17 nights have an error in the apparent radiant of the trajectory <2° and error in speed <10%. Median values of the error are 0.31° and 0.53 km/s, respectively, sufficient to resolve the intrinsic dispersion of annual meteor showers and resolve minor showers from the sporadic background. The limiting visual magnitude of the cameras is +5.4, recording meteors of +4 magnitude and brighter, bright enough to stand out from the mostly fainter sporadic meteors detected as under dense radar echoes. CAMS readily detected all established showers (6) active during the clear nights in November. Of the showers that needed confirmation, we confirm the theta Aurigids (THA, IAU#390), the chi Taurids (CTA, IAU#388), and the omicron Eridanids (OER, IAU#338). We conclude that the iota November Aurigids (IAR, IAU#248) are in fact the combined activity of the theta Aurigids and chi Taurids, and this shower should be dismissed from the list. Finally, there is also a clustering consistent with the zeta Cancrids (ZCN, IAU#243), but we cannot exclude that this is lower perihelion dust belonging to the Orionid shower. Data are submitted to the IAU Meteor Data Center on a semi-regular basis, and can be accessed also at http://cams.seti.org.

The flux of interstellar particles detected in the Solar System

AbstractThe present work shows the proportion of interstellar meteors from different mass ranges (exceeding 20 orders of mass scale) detected by various observational techniques. Having analysed the IAU Meteor Data Center, we find that the mass index of interstellar particles continuously increases towards higher masses, but there is a significant change between 10−10 − 10−11 kg. This break is possibly caused by different physical processes leading to different populations of interstellar particles and might be connected with their origin.

The occurence of interstellar meteoroids in the vicinity of the Earth

AbstractIf interstellar meteors are present among the registered meteor orbits, the distribution of the excesses of their heliocentric velocities should correspond to the distribution of radial velocities of close stars. Hence, for the velocity vi = 20 kms−1 of an interstellar meteor (with respect to the Sun) we obtain a heliocentric velocity vH = 46.6 kms−1 of an interstellar meteor arriving at the Earth. Moreover, a concentration of radiants to the Sun's apex should be observed. An analysis of the hyperbolic meteors among the 4581 photographic orbits of the IAU Meteor Data Center showed that the identification of the vast majority of the hyperbolic orbits in these catalogues has been caused by an erroneous determination of their heliocentric velocity and/or other parameters. Any error in the determination of vH, especially near the parabolic limit, can create an artificial hyperbolic orbit that does not really exist. On the basis of photographic meteors from the IAU MDC, the proportion of possible interstellar meteors decreased significantly (greater than 1 order of magnitude) after error analysis and does not exceed the value 2.5 × 10−4. Neither any concentration of radiants to the Sun's apex, nor any distribution following the motion of interstellar material has been found.

Current Status of the Photographic Meteoroid Orbits Database and a Call for Contributions to a New Version

A central depository for meteor orbits obtained by photographic techniques, as a part of the IAU Meteor Data Center, was moved to the Astronomical Institute of the Slovak Academy of Sciences in Bratislava in 2001. The current version of the catalogue contains data on 4581 meteor orbits obtained by 17 different stations or groups from the period 1936 to 1996. Since 1996 a few huge campaigns were organised including very successful Leonids and Perseids. That is why we would prepare a new more complete version of the database. The main aim of this paper is a call to the observers of meteors having new or recalculated/remeasured data on photographic meteors to send them to the MDC, where after a check and consultations with the observer, the orbits will be included in the database.

Filaments within the Perseid meteoroid stream and their coincidence with the location of mean-motion resonances

Positions of 17 filaments found inside the Perseid meteoroid stream by method of indices are compared with those of low-order mean-motion resonances with Jupiter and Saturn. By this comparing, the Jupiter and Saturn branches of the Perseid stream were identified. The existence of gaps in the distribution of the semi-major axes of the Perseids is confirmed using the more numerous material of a new version of the IAU Meteor Data Center Catalogue. Our integrations of the motion of particles in the Perseid stream lead to an extraordinary important fact. The found filaments are located in close proximity of strong resonances. They represent, with a high probability, increased numbers of particles gravitationally expelled from a resonant gap and (temporary) settled down in its close proximity.