Photometry and colors of NEAs at the origin of meteor showers

Transcription

1 Astronomical Institute, Romanian Academy Photometry and colors of NEAs at the origin of meteor showers B. A. Dumitru 1,2,3,4,M. Birlan 2,3, M. Popescu 3,2, A. Sonka 3, A. Nedelcu 3,2 1- Institute of Space Science (ISS), Magurele, Romania 2- Paris Observatory, Paris, France 3- Astronomical Institute of Romanian Academy, Bucharest Observatory, Bucharest, Romania 4- Faculty of Physics, Bucharest University, Bucharest, Romania Faculty of Physics, Bucharest University

2 Abstract Near-Earth Asteroids and comets are the parent bodies of meteor showers. The association between meteor showers and their possible parent bodies are usually based on dynamical elements similarity. However, the parent body physical properties are essential in characterizing meteoroids production, size and mineralogical composition. These characteristics are very important mainly in the case of NEAs possible parent bodies. From our dynamical analysis, 41 of meteor showers have probabilities to be produced by asteroids. Our sample of asteroids contains more than 1,000 objects, all of them belonging to the Near-Earth Asteroid population. Into our sample, we reproduce the association of 3200 Phaeton to Geminid meteor shower, as well as the association of 1991 AQ to Northern delta Capricornids. Some of our associations are puzzling while the results seem to diverge from the one of the literature. A systematic approach concerning the physical properties of our sample was performed and reinforced the link between asteroids and the associated meteor shower. An observational campaign was started in 2014 at Pic du Midi 1 meter telescope for the characterization of NEAs potential parent bodies of meteors. Five objects were observed in April 2016 in order to obtain colors and lightcurves. The results of this campaign will be presented. 11/7/2016 IAC Winter School 2

3 Introduction Our present knowledge is that at the base of meteor showers is found to small bodies of the solar system (comets and asteroids). The processes which produce the fragments for meteor showers are [D. Jewitt, H. Hsieh, J. Agarwal(2015)]: ejection and disaggregation at impacts rotational instabilities electrostatic repulsion radiation pressure dehydration stresses thermal fracture sublimation of ice The aim of this study was to determine the relationship between asteroids at the origin of meteor streams. Fig. 1. Earth moving through meteoroid debris 11/7/2016 IAC Winter School 3

4 Fig. 2. The position of associated asteroids in the solar system, in a diagram of eccentricity vs semi-major axes. In the first representation we have all objects from the IAU Minor Planet Center (all asteroids - grey), all established meteor showers (red) and planets from Mercury to Jupiter (green). The black rectangle represents a zoom were the used metrics found asteroids associated with meteor showers. This zoom is a representation where we have all the associated asteroids (1086 objects) by all metrics used DACS - red,$dsh - green, DH - blue) and the associated meteor shower (violet) [Dumitru B. A., et al 2016, in Proceedings of the International Meteor Conference Egmond, the Netherlands, 2-5 June 2016, ed. A. Roggemans & P. Roggemans, 69 72]. 11/7/2016 IAC Winter School 4

5 Analysis procedure The analysis was made with Maxim DL (Fig. 3). This is an astronomical software created by Cyanogen Imaging for the intended purpose of astronomical imaging. The periodogram for composite lightcurve was made on NASA Exoplanet Archive Periodogram Service. The service supports three algorithms: Lomb-Scargle, Box-fitting Least Squares (BLS) and Plavchan. We used Lomb-Scargle algorithm. Fig. 3. Maxim Dl interface Other software used: Aladin, Origin Fig. 4. Periodogram for asteroid /7/2016 IAC Winter School 5

6 Results - Colors Table 1. Colors obtain for the observed objects. 1999FK21 was associated with Daytime xi Sagittariids (XSA) and 2004FG11 was associated with Daytime zeta Perseids (ZPE). The object 333P/Linear is a comet that was discovered as the near-earth asteroid 2007 VA85 by the LINEAR asteroid survey (MPEC 2007-V72). Nb. Object G-R G-I Color Reflectance Color Reflectance 5141 Tachibana VR FK FG P Linear /7/2016 IAC Winter School 6

7 Results - Lightcurve Fig asteroid composite lightcurve with a period of 3.63 h Fig asteroid composeite lightcurve with a period of 5.99 h (363599) 2004FG11 is a binary asteroid [Taylor P.A et al. (2012) FG11 CBET 3091]. For this asteroid we found in the literature that the primary period is smaller then 4 hours and an period of 22 hours for the system. From our data we found that the asteroid has an primary period smaller then 6 hours (Fig. 5). 11/7/2016 IAC Winter School 7

8 Fig. 7. The first representation is the lightcurve for from THE MINOR PLANET BULLETIN VOLUME 41, NUMBER 4, A.D OCTOBER-DECEMBER and the second representation is the lightcurve obtained form our periodogram (Fig.5). 11/7/2016 IAC Winter School 8

9 Conclusions We observe four asteroids and an comet For all five objects were obtain colors and reflectance (Table 1). Asteroid (363599)2004FG11 was observe for approximate 4.5 hour in two nights. The results obtain are not similar to those found in literature. 11/7/2016 IAC Winter School 9