The CILBO meteor orbit database Thomas Albin1,2, Detlef Koschny3,4, achel !oja1, alf !rama1 and B"örn $oppe2 1. Instit'te of S%ace Systems, University of St'tt*art, Pfa+en,aldring 2-, 7/01- St'tt*art, Germany& [email protected]'tt*art.de, [email protected]'tt*art.de, [email protected]'tt*art.de 2. 5edical Radiation Physics, Fac'lty VI, Carl von Ossiet89y University, 2112- Oldenb'r*, Germany thomas.albin@uni-oldenb'r*.de, b"oern.po%%e3'ni-oldenb'r*.de 3. :'ro%ean S%ace A*ency, E!A;:!T:C, Ke%lerlaan 1, 22/1 A< Noord,ij9 Z>, Netherlands detlef&[email protected] 4. Chair of Astrona'tics, Technical Univ& 5'nich, Bolt8mannstra?e 10, 80.4@ Garching, Germany Abstract The double4station meteor cameras of the CILBO ACanary Islands Lon*4Baseline Obser)atory) obser)e the same )olume in the atmosphere abo)e the islands Tenerife and La $alma& The set'% allo,s a stereoscopic vie, of meteors that is suitable for meteor orbit determination AKoschny et al. 2013, Koschny et al. 2014)& The CILBO system has obser)ed o)er 15,/// meteors simultaneously since operation began in 2012. The soft,are pac9age C5eteor Orbit and Tra"ectory !oft,areC AKoschny D Dia8 2002) ,as eEtended by a 5onte4 Carlo based a%%roach to compute orbital elements and other Fight dynamic properties& The results are sa)ed in a database and are used by :!ACs 5eteor esearch Group and collaboratin* institutes& In this ,or9 ,e present an o)ervie, of the database and its content& Ge give a summary of certain stream detections, the sporadic bac9*round and the detected source regions& Key words. CILBO – do'ble station – meteor – orbit determination - database References: Koschny, D. & Dia8 del Rio, J., „5eteor Orbit and Tra"ectory Soft,are (5OT!B - Determining the Position of a 5eteor ,ith Respect to the Earth Usin* Data Collected with the !oft,are Met ecK, G2=, Journal of the International Meteor Or*anization, 2//2, 3/, 8.-1/1 Koschny, D.; Betton)il, F&L Licandro, J.; L'ijt, C. v& d.; Mc A'li+e, J.; Smit, H.; S)edhem, H.; de Wit, F.; Witasse, O. & <ender, J., „A do'ble-station meteor camera set4'% in the Canary Islands – CILBOK, 2eoscientific Instr'mentation, Methods and Data Systems, 2/13, 2, 33--34@ Koschny, D.; Mc A'liffe, J.; Drolsha*en, :&L Betton)il, F.; Licandro, J.; van der L'ijt, C.; Ott, T&L Smit, H&L S)edhem, >.; Witasse, O& D Zender, J., „CILBO - Lessons learned from a double-station meteor camera set'% in the Canary Islands“, Ra'lt, J.-L. & Ro**emans, P., editors, $roceedin*s of the International Meteor Conference, 2iron, France, 1@-21 Se%tember 2/14, I5O, pa*es 1/-10 COLLISION WITH METEOROIDS AS ONE OF POSSIBLE MECHANISMS OF COMETARY NUCLEI’ SPLITTING by Guliyev A.S. - The results of the statistical analysis of the dynamic parameters of 114 comets undergoing to nuclear splitting are presented in the article. The list of the objects contains: splitted in the period of the observation comets; one fragment from each comet couples; the lost comets with designation D; comets with large-scale formations in the atmosphere. Some aspects of the following hypothesis are studied: disintegration of the comet nuclear happens us results of their collision with meteoroid streams. For the verification of this hypothesis the position of splitted comet’ orbits relatively to 58 meteor streams from Cook’ catalogue is analyzed. Number (N) of orbital nodes of splitted comets according to the distances 0.001, 0.005, 0.01, 0.05 и 0.1 a.u. from each stream is calculated. For the determination of the exceed’ measure of N the special algorithm is developed. It allows to find the expected value and dispersion for these comet nodes. Comparative analysis of the parameter N in 29 cases displays its redundancy. It means one of possibility reasons of disintegration of comet nuclear is their collision with meteoroids in the streams. Asteroid and Kuiper belts as potential sources of vast number of sporadic meteoroids are tested similarity. According of results of calculations first of them may be considered the most efficient region of the disintegration of the periodic comets. Probability of coincidental clustering among the orbits of small bodies T. J. Jopek (1), M. Bronikowska (2) (1) Institute Astronomical Observatory, Faculty of Physics, A.M. University, Poznan,´ Poland, (2) Institute of Geology, A.M. University, Poznan,´ Poland Introduction searched for clusters or the size of the identified group. It is different for groups of 2, 3 ... members. Of course The major tool for finding clusters among small bodies it depends on the cluster analysis method applied. of the Solar System has been orbit similarity, quanti- We tested the impact of some of these factors. For fied by a function called D-criterion. Finding a very a given size of the orbital sample we have assessed similar orbits among the asteroids, comets or mete- probability of random grouping for several groups of oroids always rise a question — whether such simi- different sizes. On the other hand, for a given size of larity is only a chance coincidence? To give answer the identified group we have found how these proba- we need an adequate value of the orbital similarity bilities vary with the size of the orbital samples. threshold (a key parameter of any cluster analysis) cor- Finally, keeping fixed size of the orbital sample and responding to the value of the probability of a chance the size of the group, we have shown that the probabil- similarity between two or more orbits. ity of random grouping can be significantly different Reliability of orbital grouping is quite old problem, for the orbital samples obtained by different observa- first time engaged in [5] and [3]. However, due to limi- tion techniques. tation of the computing power at that time it was rather This result is important, it means that contrary to problematic to accomplish an extensive reliability test quite common practice we should rather not use the of detected groups. So no values of the probabilities values of the orbital similarity thresholds applied by were assigned to the identified pairs or groups of me- someone in earlier study e.g. for searching for streams teor orbits. Afterwards the problem was elaborated among video orbits. For given orbital sample and the more extensively in [1, 2] or more recently in [4]. cluster analysis method one should find the proper val- ues of the orbital similarity threshold for each group of 2,3,4, ... members, severally. Our work In this study we made use of our earlier experiences References [1] and the approach described in [4]. Both methods [1] Jopek, T.J., Froeschlé Cl., 1997, A&A, 320, 631 are based heavily on the artificial orbital samples. We [2] Jopek T.J. Valsecchi, G. B., Froeschlé Cl., 2003, have shown that both methods give consistent results MNRAS, 344, 665 but the method proposed in [4] needs more computing [3] Nilsson C.S., 1964, Aust. J. Phys., 17, 205 power. [4] Pauls A., Gladman B., 2005, M&PS, 40, 1241 Sets of the synthetic meteoroid’s or asteroid’s orbits [5] Southworth R.B., Hawkins G.S., 1963, Smiths. one can generate in different ways: Contr. Astroph.,7, 261 • using different statistical properties of the orbital elements generated randomly, • by taking (or not) into account correlation be- tween some orbital elements. We have investigated how such different methods im- pact assessment of the probability of pairing or group- ing among the orbits? Probability of random grouping depends on sev- eral other factors like the size of the orbital sample Impact detections of temporarily captured natural satellites David L. Clark1,2,3, Pavel Spurný4, Paul Wiegert2,3, Peter Brown2,3, Jiří Borovička4, Ed Tagliaferri5, Lukáš Shrbený4 1 Department of Earth Sciences, University of Western Ontario, London, ON N6A 5B8, Canada 2 Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 5B8, Canada 3 Centre for Planetary Science and Exploration, University of Western Ontario, London, Ontario N6A 5B8, Canada 4 Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondřejov, Czech Republic. 5 ET Space Systems, 5990 Worth Way, Camarillo, California 93012, USA Abstract: Temporarily Captured Orbiters (TCOs) are Near-Earth Objects (NEOs) which make a few orbits of Earth before returning to heliocentric orbits. Only one TCO has been observed to date, 2006 RH120, captured by Earth for one year before escaping. Detailed modeling predicts capture should occur from the NEO population predominantly through the Sun-Earth L1 and L2 points, with 1% of TCOs impacting Earth and approximately 0.1% of meteoroids being TCOs. Although thousands of meteoroid orbits have been measured, none until now have conclusively exhibited TCO behaviour, largely due to difficulties in measuring initial meteoroid speed with sufficient precision. We report on a precise meteor observation of January 13, 2014 by a new generation of all-sky fireball digital camera systems operated in the Czech Republic as part of the European Fireball Network, providing the lowest natural object entry speed observed in decades long monitoring by networks world-wide. Modeling atmospheric deceleration and fragmentation yields an initial mass of ~5 kg and diameter of 15 cm, with a maximum Earth- relative velocity just over 11.0 km/s. Spectral observations prove its natural origin. Back- integration across observational uncertainties yields a 92 - 98% probability of TCO behaviour, with close lunar dynamical interaction. The capture duration varies across observational uncertainties from 48 days to 5+ years.