NEAR-EARTH ASTEROID PHOTOMETRY IN FRAME OF ISON PROJECT: DETECTION OF BINARIES Yu. Krugly1, I. Molotov2, R. Inasaridze3, V. Aivazyan3, O. Kvaratskhelia3, V. Zhuzhunadze3, I. Belskaya1, V. Chiorny1, T. Hromakina1, A. Sergeyev1, V. Shevchenko1, I. Slyusarev1, V. Rumyantsev4, Sh. Ehgamberdiev5, O. Burkhonov5, L. Elenin2, V. Voropaev2, V. Kouprianov6, M. Krugov7, A. Kusakin7, I. Reva7, N. Gaftonyuk4, A. Baransky8, Z. Donchev9, G. Borisov9, T. Irsmambetova10, A. Matkin11, D. Erofeev11, S. Schmalz12, T. Namkhai13, A. Wolf14, V. Kashuba15, V. Troianskyi15 The 4th Workshop on Binaries in the Solar System Prague, Czech Republic 2016 June 21-23

ISON OBSERVATORIES Chuguev Observatory, Kharkiv, Ukraine Keldysh Institute of Applied Mathematics, Moscow, Russia Kharadze Abastumani Observatory, Tbilisi, Georgia Crimean Astrophysical Observatory, Nauchny, Crimea Maidanak Observatory, Tashkent, Uzbekistan Pulkovo Observatory, St.-Petersburg, Russia Tien-Shan Observatory, Almaty, Kazakhstan Lisnyky Observatory, Kyiv, Ukraine Rozhen Observatory, Sofia, Bolgaria Sternberg Astronomical Institute, Moscow, Russia ISON-Ussuriysk Observatory, Russia Leibniz Institute for Astrophysics, Potsdam, Germany Huraltogoot Observatory, Ulan-Bator, Mongolia Altai State Pedagogical University, Barnaul, Russia Mayaki Observatory, Odessa, Ukraine

INTERNATIONAL SCIENTIFIC OPTICAL NETWORK (ISON) Started in 2004, currently the project involves more than 30 observatories and scientific institutions in 15 countries: Russia, Ukraine, Moldova, Georgia, Uzbekistan, Tajikistan, Kazakhstan, Italy, USA, Bolivia, Armenia, Switzerland, Spain, Mongolia, Mexico. There are more than 70 telescopes in the network. The work is a part of long-term agreements on a scientific and technical cooperation between the Keldysh Institute of Applied Mathematics (KIAM, Moscow) and scientific or educational organizations, using both their own instruments (telescopes) in the possession of the organization, as well as instruments provided by the ISON project.

WORLD OF ISON

THE NETWORK AIMS Monitoring of space debris by means of carrying out astrometric and photometric observations of Earth-orbiting objects Tracking of near-Earth asteroids (NEAs): to discover and refine orbital parameters; to study physical properties of NEAs The ISON facilities: 18 telescopes of 0.4-0.7 m 3 telescopes of 1 m 1.5 m and 2.6 m telescopes

ASTEROID PHOTOMETRY The telescopes with diameters from 40 cm up to 2.6 m have been modernized and used in the network for carrying out photometry of asteroids. Most of these telescopes have been equipped with modern CCD cameras, mainly manufactured by the firm Finger Lakes Instrument (USA).

GOALS OF ASTEROID PHOTOMETRY Physical characteristics of Near-Earth Asteroids Observations of Potentially Hazardous Asteroids (PHAs), especially newly discovered NEAs Search for binary asteroids and determination of parameters of binary systems Investigation of the YORP effect: detection of the influence on asteroid’s rotation Support of radar observations of NEAs by optical observations

Binary Asteroids Observed in 2013-… Orbit Type H mag Diameter Km Albido Rot. Period hrs Q Ampl 4034 Vishnu (r) Аполлон O 18.4 0.42 0.52 ~15.46 2,N > 0.3 7888 1993 UCB (r) U;S 15.1 2.72 0.18 2.3386 ± 0.0004; P2 ~ 51.2 h ± 0.2 3!, B-N 0.09; 0.2 17188 1999 WC2 (r) - 16.5 1.5 - 3.4 5.063 ± 0.001 0.43 24445 2000 PM8 (r) Амур 14.6 3.6 - 8.1 6.805h ± 0.003 0.29-0.37 68216 2001 CV26B(r) Sq 16.4 1.36- 3.5 0.26 2.4295 ± 0.0005 P2~16..25h(19.7;25.) 0.17; min=0.04 137126 1999 CF9 (r) 18.0 0.9 ~ 7 ~0.55 137805 1999 YK5 Атон X;RQ 16.60 1.5 3.468h ±0.008 0.12 163249 2002 GTB (r) S 18.5 1.3-0.6 3.764 ± 0.002 0.36 203471 2002 AU4 19.30 0.9-0.4 > 6 > 1.1 285263 1998 QE2B (r) Ch 16.98 2.75 0.06 4.7493 ± 0.0005 0.19 329437 2002 OA22 (r) 19.4 2.6211h ± 0.0005 0.20 361071 2006 AO4 15.5 2.4 - 5.4 4.0895 ± 0.0005 0.32

RESULTS OF PHOTOMETRY About 190 NEAs were observed in 2013-2016, among them 18 were binaries, about 30 NEAs had been suspected to be binary, signs of possible binarity for 7 of them were actually found

(8373) STEPHENGOULD 2010 OPPOSITION Mars-crosser from Hecuba group: Kirkwood gap at the 2:1 mean motion resonance with Jupiter; unstable asteroids with lifetime <10 Myr 2010 OPPOSITION i = 40.77° e = 0.55 a = 3.28 AU q = 1.47 AU Q = 5.10 AU Porb = 5.95 yr H = 14.64 D = 3-6 km ASTEROID TAX. CLASS D1 (km) P1 (hrs) A1 (mag) D1/D2 R/D1 (ρ=1/2) P2 YEAR 8373 Stephengould (EMP) 3.86 4.435 0.33-0.39 >0.27 2/3 34.1 2010

(8373) STEPHENGOULD On Jan.17-18, 2010 two binary evens have been registered and orbital period was estimated as results of observations at Chuguev Observatory (Ukraine)

(8373) STEPHENGOULD BinAstSurvey observations Evens on Jan.17-27, 2010

(8373) STEPHENGOULD March-June 2010: NO EVENTS FOUND

(8373) STEPHENGOULD in 2014 Previously the asteroid was observed in Jan. 2004 by Brian Warner In 2010 new analysis of the data showed one event on Jan. 09, 2004

(8373) STEPHENGOULD in 2015-2016 Jan. - Feb. 2016 Nov. - Dec. 2015 Apr. 2016 May 2016

337866 (2001 WL15) H = 18.8; Sk-type (Binzel et al. 2004); D = 530 m Radar target at Arecibo in Dec 2015-Jan 2016 Asteroid was observed at Abastumani Observatory in March 2016 Short-period lightcurve Long-period component

337866 (2001 WL15) Observed by Hicks (2016): published in The Astronomer’s Telegram Long period could be connected with binary nature Warner informed about the rotation period 8.955 hrs

163246 (2002 GT) Chesley et al. (2013) informed about indication that it might be a binary system from its photometry in April 2013.

2002 GT campaign in frame of Gaia-FUN-SSO June - July 2013 NEA 2002 GT is a target of the Deep Impact spacecraft (flyby on Jan. 2020). 585 Lisnyky: Jun 10, 24-25 095 Nauchny: Jun 10-11 094 Simeiz: Jun 12-13, 20; Jul 12 119 Abstumani: Jun 19-20, 30 121Chuguev: Jun 19 190 Gissar: Jul 04 188 Maidanak: Jul 5

2013 TV135 October-December 2013 119 Abastumani: Oct 21-22, 24-25; Dec 4 121 Chuguev: Oct 23; H15 ISON-NM: Oct 17, 19, 22, 24, 27

SUMMARY We made many follow-up observations of known NEA binaries. We should continue the observations trying to improve them by using more telescopes, especially more telescopes of larger apertures, located in different observatories. Search of a binary among NEAs is very time-consuming, and requires better cooperation between observatories around the world.

ACCURACY OF PHOTOMETRY The lightcurves example: NEA (3554) Amun observed in the network V=16 mag, RMS = 0.03 mag V=16 mag, RMS = 0.02 mag V= 14 mag, RMS = 0.007 mag V= 15 mag, RMS = 0.01 mag The typical accuracy is 0.01-0.02 mag and no worse than 0.03-0.04 mag.