PHOTOMETRIC OBSERVATIONS OF ASTEROIDS IN FRAME OF ISON PROJECT

Transcription

1 ХАРКІВСЬКИЙ НАЦІОНАЛЬНИЙ УНІВЕРСИТЕТ ім. В.Н.Каразіна НАУКОВО-ДОСЛІДНИЙ ІНСТИТУТ АСТРОНОМІЇ 61022, м. Харків, вул. Сумська, 35 тел., факс: (057) , PHOTOMETRIC OBSERVATIONS OF ASTEROIDS IN FRAME OF ISON PROJECT Yurij Krugly,, I.E. Molotov, V.M. Agapov,, L. Elenin, N.M. Gaftonyuk,, V.V. Kouprianov,, N.H. Minikulov, M.I. Gulyamov,, Z. Donchev,, V. Ivanova,, A.V. Sergeev, V.V. Rumyantsev, R.Ya. Inasaridze,, T.V. Kryachko, N.I. Dorokhov

2 ISON - International Scientific Optical Network Started in 2004, currently, the project involves more than 20 observatories and scientific institutions in 10 countries (Russia, Ukraine, Moldova, Georgia, Uzbekistan, Tajikistan, Italy, Bolivia, Switzerland, Spain). The works are part of long-term agreements on scientific-technical cooperation between the Keldysh Institute of Applied Mathematics (KIAM, Moscow) and related scientific or scientific-educational organizations, using both their own instruments (telescopes) in the possession of the organization, as well as instruments that, under agreements places the KIAM (or those and other tools are used together). The project presented at the UN and the results obtained are highly appreciated as colleagues from various scientific organizations, and at the level of a number of foreign space agencies (ESA, NASA, JAXA). 23/09/2010 Photometry asteroids in ISON 2

3 The aims of the ISON project Monitoring of man-made space debris (primarily high-geostationary orbits, high-elliptical, circular type of GLONASS and GPS) by means of carrying out astrometric and photometric observations of orbiting objects (i.e. the study of their orbital and physical properties), prediction long-term evolution of this state, taking into account various factors, identify the sources of formation of small debris, identifying objects of potential sources of risk to the functioning for operational spacecrafts. This is the main task. Tracking of near-earth asteroids (NEAs), to do the discovery and to study their physical properties and refinement of orbital parameters. This is an additional task 23/09/2010 Photometry asteroids in ISON 3

4 Map of observatories in the network 23/09/2010 Photometry asteroids in ISON 4

5 Telescopes in the network More then 20 wide-field telescopes were made and installed at different observatories of the network. The diameters are from 12.5 up to 50 cm, with filed of view on several degrees. 23/09/2010 Photometry asteroids in ISON 5

6 Telescopes in the network The old telescopes with diameters from 60 cm up to 2.6 m have been modernized and using in the network. Most of these telescopes have been equipped with modern CCD-cameras, mainly manufactured by firm Finger Lakes Instrument (FLI) in USA 23/09/2010 Photometry asteroids in ISON 6

7 INSTITUTE of ASTRONOMY of KHARKIV KARAZIN NATIONAL UNIVERSITY, UKRAINE :// 23/09/2010 Photometry asteroids in ISON 7

8 PHYSICS of ASTEROIDS and COMETS DEPARTMENT INSTITUTE of ASTRONOMY (15898) KharAsterTeam am 23/09/2010 Photometry asteroids in ISON 8

9 Chuguev Observation Station, Kharkiv 70-cm telescope 23/09/2010 Photometry asteroids in ISON 9

10 Kharkiv Program: CCD Observations of Near-Earth Asteroids (NEA) Started in 1995 joined with: DLR PLANETARY INSTITUTE, BERLIN Participants in Kharkiv Observatory: Yurij Krugly Irina Belskaya Vasilij Chiorny Vasilij Shevchenko Feodor Velichko Since 1996 the program is carried out jointly with: CRIMEAN ASTROPHYSICAL OBSERVATORY 23/09/2010 Photometry asteroids in ISON 10

11 Simeiz Observatory, Crimea 1-m m telescope 23/09/2010 Photometry asteroids in ISON 11

12 Main Aims of the Program PHYSICAL PARAMETERS OF NEAR-EARTH ASTEROIDS BY PHOTOMETRY TO OBTAIN: ROTATION PROPERTIES SURFACE PROPERTIES DIAMETERS SHAPE MODELS FOLLOW-UP ASTROMETRY AND PHOTOMETRY OF NEWLY DISCOVERED NEAs IN FRAME OF EUROPEAN ASTEROID HAZARD PROGRAM 23/09/2010 Photometry asteroids in ISON 12

13 MAIN RESULTS OF THE NEAs PROGRAM Up to 2005 it has been observed more than 100 NEAs and obtained in result: more than 500 lightcurves rotational periods: 60 (45 for the first time) absolute magnitudes: 60 binary asteroids: 6 photometric models: 6 23/09/2010 Photometry asteroids in ISON 13

14 ROTATION PERIOD ABSOLUTE MAGNITUDE Obtained up to N= mag 21.5 mag Rotation period, hours Rotation period, hours P=2.2 hr N=338 - All observed NEAs - Observed in Kharkiv Magnitude Magnitude P=2.2 hr 23/09/2010 Photometry asteroids in ISON 14

15 Asteroid Observations in frame of ISON Since 2006 Kharkiv Asteroid Group cooperates with ISON Several ISON observatories are involved in photometry of asteroids. THE MAIN DIRECTIONS OF OUR RESEARCHES: Physical properties of the Near-Earth Asteroids Observations of newly discovered NEAs and Potentially Hazardous Asteroids (PHAs) firstly Searching for binary asteroids and determining parameters of the binary systems Support in optics of asteroid s radar observations Investigation of Yarkovsky-O Keeffe-Radzievskii-Paddack effect (YORP-effect) the influence on asteroid s rotation 23/09/2010 Photometry asteroids in ISON 15

16 Crimean Astrophysical Observatory, Nauchnyi 2.6-m m telescope 23/09/2010 Photometry asteroids in ISON 16

17 Rozhen Observatory, Bulgaria 2-m m telescope 23/09/2010 Photometry asteroids in ISON 17

18 Maidanak Observatory, Uzbekistan 60-cm and 1.5-m m telescopes 23/09/2010 Photometry asteroids in ISON 18

19 Gissar Observatory, Tajikistan 70-cm telescope 23/09/2010 Photometry asteroids in ISON 19

20 Abastumani Observatory, Georgia 70-cm and 1.25-m m telescopes 23/09/2010 Photometry asteroids in ISON 20

21 ISON Observatory in New Mexico 45-cm telescope 23/09/2010 Photometry asteroids in ISON 21

22 Photometry of Asteroid 433 Eros CCD camera precision test 1 1, Эрос V(1,α=23.3 ), mag 1 1,4 0 N o v e m b e r 1 5, , U T, h o u r s 23/09/2010 Photometry asteroids in ISON 22

23 NEAR-EARTH ASTEROID LIGHTCURVES 23/09/2010 Photometry asteroids in ISON 23

24 The largest NEA1036 Ganymed Ganymed H 9.0 R H R = 9.08 G = 0.38 P= hrs April-May Rotational phase 23/09/2010 Photometry asteroids in ISON 24

25 Photometry of NEAs H R CV BQ H P = hrs Rotational phase 1980 Tezcatlipoca - V, Jul 20, R, Jul 20 - V, Jul 21 - R, Jul 21 Relative Magnitude V, Aug 2, 2006 P = hrs - R, Aug 2 - R, Aug ,0 9,2 UT(c.) QS P = hrs Rotational phase - V, Jul 22, R, Jul 22 - V, Jul 28 - R, Jul 28 - V, Jul 29 - R, Jul 29 Magnitude R 9,4 9,6 P = h - Sept. 5, ,8 0,0 0,2 0,4 0,6 0,8 1,0 Rotational phase 23/09/2010 Photometry asteroids in ISON 25

26 ASTEROID RADAR SHAPE MODELS: Lightcurves of NEA HW1 14,6 14, HW1 8,8 9, HW1 Magnitude R(1,α=0) 15,0 15,2 15,4 15,6 15,8 - Jul Aug 2008 P = 8.756hrs Relative magnitude R 9,2 9,4 9,6 9,8 10,0 - Aug Sep ,0 0,2 0,4 0,6 0,8 1,0 Rotational phase 10,2 0,0 0,2 0,4 0,6 0,8 1,0 P = hrs Rotational phase July-August 2008 August-September /09/2010 Photometry asteroids in ISON 26

27 SHAPE MODEL OF HW1: radar and photometry Magri et al. (2010), prepared for Icarus submitting 23/09/2010 Photometry asteroids in ISON 27

28 BINARY NEAR-EARTH EARTH ASTEROIDS: Asynchronous Binary NEA 2005 NB7 Observations in May Magnitude R NB7-2 мая 2008 г UT(nc) Magnitude R NB7-3 мая 2008 г UT(nc) 23/09/2010 Photometry asteroids in ISON 28

29 BINARY NEAR-EARTH EARTH ASTEROIDS: Composition lightcurve of 2005 NB NB N B Relative magnitude R Relative magnitude R P = h May Rotational phase P = h M a y R o ta tio n a l p h a s e Short-period component: Primary body rotation Long-period component: Orbital and secondary body rotation 23/09/2010 Photometry asteroids in ISON 29

30 FIRST RADAR BINARY 2000 DP107 discovered in 2000 Margot et al. (2000) IAUC 7503 Tower of Eiffel 23/09/2010 Photometry asteroids in ISON 30

31 LIGHTCURVES OF 2000 DP Reduced R magnitude Sept 29, UTc, hours Reduced R magnitude UTc, hours Oct 5, /09/2010 Photometry asteroids in ISON 31

32 Survey for Asynchronous Binary Asteroids Installed by Petr Pravec (Ondrejov Observatory, Czech Rep.) The goal of the survey is to discover asynchronous binary asteroids among small NEAs, MCs, and inner MBAs, and to do it in a controlled way that will allow to simulate selection effects and biases in obtained sample We take part in this project 23/09/2010 Photometry asteroids in ISON 32

33 Yarkovsky and YORP effect Each photon escaping from asteroid surface carries away a momentum p = hν/c. When sunlight from an asteroid s surface is reflected and re-emitted at thermal, infrared wavelengths then it produces a torque. The thermal forces of the Yarkovsky effect can cause small bodies to drift slowly towards or away from the Sun. (Rubincam, 2000) 23/09/2010 Photometry asteroids in ISON 33

34 YORP effect These thermal torques can cause small asteroids to spin up or down with time the Yarkovsky-O'Keefe O'Keefe-Radzievskii-Paddack effect or YORP effect. The direction and acceleration of the spin being determined by the shape and orientation of each body. 23/09/2010 Photometry asteroids in ISON 34

35 YORP-effect: 1862 Apollo The direct observational detection of the YORP effect on the NEA 1862 Apollo have been done in 2007 (Kaasalainen et al. 2007, Nature 446, 420). New observations in April 2008 have confirmed influence of the YORP effect on Apollo s rotation period (Durech et al. 2008, Astron. Astroph submitted). It was found that Apollo s spin behaviour cannot be explained with a simple assumption of a constant sidereal rotation period P. To achieve a data fit down to the noise level, the standard lightcurve inversion model had been extended by a linear increase in time t in the rotation speed w=2π/p: w( t) = w( t ) + dw / dt( t t ) 0 0 Apollo s model: λ p = 48 deg, β p = -72 deg P (JD ) = ± h dw/dt = (5.5 ± 1.2) x 10-8 rad/day 2 dp/dt = x 10-6 hr/year For ρ = 2.7 g/cm3, D = 1.45 km, Bond albedo = 0.1, thermal conductivity K = 0.02 W/m K predicted value of YORP acceleration is dw/dt = 8.0 x 10-8 rad/day 2 Relative magnitude R 11,8 12,0 12,2 12, Apollo 0,0 0,2 0,4 0,6 0,8 1,0 Rotational phase April /09/2010 Photometry asteroids in ISON 35

36 YORP-effect: 1620 Geographos Geographos rotation modeling with new observations in January-March 2008 has revealed the YORP acceleration of the rotation period (Durech et al. 2008, Astron. Astroph. 489, L25 L28): dw/dt = 1.1 x 10-8 rad/day 2 P = ± hr Amp = 1.3 mag (α = 15 deg) S-asteroid with D = 2.2 km H = 15.33, G =0.15 albedo = 0.26 H v Geographos λ p = 56 deg, β p = -47 deg (Magnusson et al. 1996) 16.0 Febr Rotational phase 23/09/2010 Photometry asteroids in ISON 36

37 SUPERFAST ROTATING ASTEROIDS: Diameter = 180 m NEA (54509) YORP (=2000 PH5) Period = min R(1, 60 ) 23.5 (54509) 2000 PH UT, hours July 27, /09/2010 Photometry asteroids in ISON 37

38 COMPOSITE LIGHTCURVE of (54509) 2000 PH R(1, 60 ) (54509) 2000 PH ο - July 26, Kharkiv - July 27, Kharkiv - July 27, Simeiz P = min - July 28, Simeiz Rotational Phase 23/09/2010 Photometry asteroids in ISON 38

39 ISON OBSERVATIONS IN THE FRAME OF ASTEROID HAZARD PROBLEM Discovery of new near-earth asteroids Searching of NEAs in frame of ISON project was started in June 2010 and now one NEA have been discovered Follow-up of newly discovered objects to obtain the coordinates and estimate their diameters Study of physical parameters of near-earth asteroids, the first of all newly discovered 23/09/2010 Photometry asteroids in ISON 39

40 New ISON Observation Station at Macon: under construction We have a protocol of intentions between ISON, IATE-UNC- CONICET and administration of Salta province about scientific and technical cooperation In frame of this cooperation we are planning to install wide-field 25 and 50 cm telescopes at Macon in close future. It is supposed inputting from both IATE and ISON in constructing and exploration these telescopes The telescopes will be worked in automatic regime and used both IATE and ISON for several tasks: for space debris, asteroid observations and so on 23/09/2010 Photometry asteroids in ISON 40

41 New ISON Observation Station at Macon: under construction 25-cm reflector with FOV 4x4 deg2 23/09/ cm reflector with FOV 2x2 deg2 Photometry asteroids in ISON 41

42 Thank you! 23/09/2010 Photometry asteroids in ISON 42