ARISTOTLE UNIVERSITY OF THESSALONIKI (AUTh) FACULTY OF SCIENCES SCHOOL OF PHYSICS SECTION OF ASTROPHYSICS, ASTRONOMY & MECHANICS DIPLOMA THESIS “ANALYSIS OF OCCULTATIONS AND PHOTOMETRY DATA FROM NEAR- EARTH ASTEROIDS” CHRYSOVALANTIS SARAKIS SUPERVISOR: KLEOMENIS TSIGANIS THESSALONIKI, GREECE OCTOBER 2017 2 3 Table of Contents TABLE OF CONTENTS ....................................................................................................................... 3 ABSTRACT ............................................................................................................................................ 7 ΠΕΡΙΛΗΨΗ ............................................................................................................................................ 7 ACKNOWLEDGEMENTS - INTRODUCTION ................................................................................ 9 CHAPTER 1 ......................................................................................................................................... 11 ASTEROIDS ......................................................................................................................................... 11 1.1 ORBITAL ELEMENTS ............................................................................................................ 11 1.1.1 Semi-major axis (a) .......................................................................................................... 11 1.1.2 Eccentricity (e) ................................................................................................................. 12 1.1.3 Inclination (풊/Incl) ............................................................................................................ 12 1.1.4 Longitude of the ascending node (Ω/Node) ...................................................................... 12 1.1.5 Argument of perihelion (ω/Peri) ....................................................................................... 13 1.1.6 Mean anomaly (M) ........................................................................................................... 13 1.1.7 Epoch ................................................................................................................................ 13 1.1.8 Perihelion (q) .................................................................................................................... 13 1.1.9 Aphelion (Q) ..................................................................................................................... 13 1.2 NEAR-EARTH ASTEROIDS .................................................................................................... 14 1.3 MAIN ASTEROID BELT ......................................................................................................... 14 1.3.1 Spectral Classification ...................................................................................................... 15 1.3.2 Kirkwood Gaps ................................................................................................................. 16 1.3.3 Resupply of NEOs ............................................................................................................. 17 1.3.4 Asteroid Families .............................................................................................................. 18 1.4 TROJAN ASTEROIDS ............................................................................................................. 19 1.5 CENTAURS ............................................................................................................................ 19 1.6 TRANSNEPTUNIAN OBJECTS ................................................................................................ 19 1.7 WHY DO WE STUDY ASTEROIDS? ......................................................................................... 20 PHYSICAL PROPERTIES ..................................................................................................................... 20 1.7.1 Rotation Period................................................................................................................. 20 4 1.7.2 Direction of Rotation Axis ................................................................................................ 21 1.7.3 Size .................................................................................................................................... 21 1.7.4 Shape ................................................................................................................................ 22 CHEMICAL COMPOSITION ................................................................................................................ 22 1.7.5 Reflectance Spectrum........................................................................................................ 22 CHAPTER 2 ......................................................................................................................................... 25 PHOTOMETRY ................................................................................................................................... 25 2.1 LIGHT-CURVE ANALYSIS ..................................................................................................... 25 2.2 AIR MASS .............................................................................................................................. 27 2.3 SEEING .................................................................................................................................. 27 2.4 SCINTILLATION .................................................................................................................... 28 2.5 OPPOSITION EFFECT ............................................................................................................ 28 2.6 DIFFERENTIAL PHOTOMETRY ............................................................................................. 29 2.7 BIAS-FRAME SUBTRACTION ................................................................................................ 30 2.8 DARK-CURRENT SUBTRACTION .......................................................................................... 31 2.9 FLAT-FIELD CORRECTION ................................................................................................... 32 2.9 OBSERVATIONS .................................................................................................................... 33 CHAPTER 3 ......................................................................................................................................... 35 OCCULTATIONS ................................................................................................................................ 35 3.1 WHAT IS A STELLAR OCCULTATION BY AN ASTEROID? ...................................................... 35 3.2 WHY DO WE STUDY OCCULTATIONS? ................................................................................. 37 3.3 OBSERVATIONS .................................................................................................................... 39 CHAPTER 4 ......................................................................................................................................... 41 RESULTS .............................................................................................................................................. 41 4.1 LIGHT-CURVE ANALYSIS ..................................................................................................... 41 4.1.1 Asteroid (100926) 1998 MQ ............................................................................................. 41 4.1.2 Asteroid (6974) Solti ......................................................................................................... 47 4.1.3 Asteroid (2012) Guo Shou-Jing ........................................................................................ 51 4.2 ANALYSIS OF STELLAR OCCULTATIONS BY ASTEROIDS DATA .......................................... 55 4.2.1 Occultation by (45) Eugenia, June 13 2014 ..................................................................... 55 5 ASTEROID (45) EUGENIA ................................................................................................................... 55 4.2.2 Occultation by (102) Miriam, March 03 2017 .................................................................. 59 ASTEROID (102) MIRIAM .................................................................................................................. 59 4.2.3 Occultation by (3332) Raksha, March 03 2017 ................................................................ 63 ASTEROID (3332) RAKSHA ................................................................................................................ 63 CHAPTER 5 ......................................................................................................................................... 67 CONCLUSIONS ................................................................................................................................... 67 APPENDIX ........................................................................................................................................... 69 ASTEROID (100926) 1998 MQ ............................................................................................................ 69 Attempt to track the asteroid .......................................................................................................... 69 Attempt to track the