Capabilities of the Terskol Observatory for follow-up observations of Solar System objects within the Gaia mission Vira Godunova , V. Tarady, O. Sergeev, M. Andreev, V. Reshetnyk, A. Simon ICAMER Observatory, NASU, 27 Zabolotnoho St., 03680 Kyiv, Ukraine V_Godunova@bigmir.net Fig 4. On the left: Sky map and Gaia’s track from http://gbot.obspm.fr On the right: Image of Gaia obtained with the 2-m telescope at Terskol on 2015, March 10 (exposure time 60 s). Observatory and instruments Starting in 1996, the facilities of the Terskol Observatory (the Northern Caucasus, 3120 m asl) have been heavily used for follow-up studies of comets and asteroids. The available small and medium-sized telescopes provide good enough opportunities for astrometric, photometric, and spectroscopic observations of these objects [1]. CONCLUSIONS Small- and medium-aperture telescopes still provide good enough opportunities for follow-up studies of small Solar System objects. More systematic, integrated use of small and medium- aperture telescopes could lead to better information about the potentially hazardous objects. The telescopes Zeiss-2000 and Zeiss-600 at the Terskol Observatory have been successfully used for follow-up astrometry of Gaia and asteroids detected within the Gaia project. To date, positions of a number of these objects were detected; an accuracy is on average 0.2- 0.3 arcseconds. The observed coordinates of a newly detected asteroids or improved astrometric data for known objects have been continuously reported to the Minor Planet Center. REFERENCES [1] Tarady, V., Sergeev, O., Karpov, N., Zhilyaev, B., and Godunova, V. “Observations with Small and Medium-Sized Telescopes at the Terskol Observatory”, 25 March 2010, http://arxiv.org/pdf/1003.4875 [2] Godunova, V., Reshetnyk V., Zhilyaev B., Andreev M., 2014, Determining rotation periods of NEAs from optical observations at the Terskol Observatory, EPSC Abstracts, Vol.9, EPSC2014-797 [3] Godunova, V., M. Andreev, O. Sergeev, V. Tarady, V. Reshetnyk, 2015, Follow-up observations of NEAs at the Terskol Observatory, in: Proc. of 3 rd Gaia-FUN-SSO workshop (Paris, France, Nov 24-26, 2014), eds. P.Tanga & W.Thuillot, IMCCE/Obs. Paris, ISBN 2-910015- 73-4 – pp.131-135 www.imcce.fr/hosted_sites/gaiafun2014/documents.php Fig. 1. Gaia, as seen with the aid of the 60-cm telescope (processed with Astrometrica) Fig. 5 . Composite image of G01237 (~19.4 m ) formed by combining two stacked images obtained on 17 and 18 May 2015 with the 2-m telescope. The 60-cm Cassegrain telescope (Zeiss-600) is the main instrument for follow-up astrometry, photometry and spectroscopy of asteroids. This f/12.9 reflector has two CCD cameras. The one recently mounted is a SBIG STL-1001 based on 1024x1024 CCD with 24 micron pixels that provides a field of view of 10.9 x 10.9 arcmin. The limiting V magnitude for this telescope is 20.5 m . We report here observations in support of the Gaia mission, which have been obtained at the Terskol Observatory (the Northern Caucasus, 3120 m asl) with the aid of optical telescopes with diameters up to 2 m. For almost 20 years, the Terskol Observatory has produced useful observational datasets that contribute significantly to achieving advances in studies of Solar System small bodies. New techniques and methods applied allow us to provide observations with sufficient accuracy of both fast moving objects and transient events. Appropriate software developed has been used to determine rotation properties and spectral class of asteroids. In addition to continuous studies of newly detected Earth-approaching objects, follow-up observations of the Gaia spacecraft have been started at Terskol in 2015; an accuracy of about 0.1 arcsec was achieved. Observations In 2003-2015, positions of more than 200 NEAs were detected; an accuracy of much better than 0.6 arcsec (on average 0.2–0.3 arcsec) was achieved (Fig. 2). Astrometric observations have been continuously reported to the IAU Minor Planet Center. Appropriate software developed has been applied to derive asteroid’s properties and to classify them. [2,3]. 2-m RCC telescope Main mirror d=2m, f= 5.6m Ritchey-Chretien system equivalent focal length: 16 m field of view: 108’ Coude system equivalent focal length: 72 m field of view: 5’ CCD Camera FLI PL4301 : 2084 x 2084 pixels (pixel size 24x24 micron) Field of view: 11x11 arcmin The photometric complex of the 2-m telescope includes a two-channel high-speed photometer with cooled photo-multipliers, UBVRI filters and a CCD guiding system. This complex has a precise timing and synchronization system based on the GPS smart antenna Acutime-2000. The accuracy of the timing and synchronization is better than l ms. High-resolution Echelle spectrograph Multimode spectrometer High-speed two-channel photometer Several specified photometers and CCDs 60-cm telescope Fig. 3. Position uncertainties plotted against R magnitude of NEAs observed in 2013 at the Terskol Observatory Observations of Gaia It is a difficult task because Gaia’s magnitude ranges between 20.2 and 21.6; moreover, full Moon does not allow one to detect this object. The Gaia satellite were observed at Terskol during several nights in February-May 2015. ============================================================== DASO Circular No. 516 Issued: 2015 Apr. 25, 03:50 UT The DISTANT ARTIFICIAL SATELLITES OBSERVATION (DASO) Circulars are a private publication by staff of the Minor Planet Center and are intended to disseminate astrometric observations of distant artificial satellites. Editor: Gareth V. Williams (gwilliams@cfa.harvard.edu) Astrometry submissions to obs@cfa.harvard.edu (Subject line = "ART SAT") Observations: … Gaia C2015 03 10.79140 11 01 23.05 +12 48 40.1 21.5 R D0516B18 Gaia C2015 03 10.79215 11 01 23.12 +12 48 39.1 21.1 R D0516B18 Gaia C2015 03 10.79366 11 01 23.21 +12 48 38.1 20.6 R D0516B18 Gaia C2015 03 10.79441 11 01 23.28 +12 48 37.1 20.6 R D0516B18 Gaia C2015 03 10.79516 11 01 23.34 +12 48 36.2 20.5 R D0516B18 Gaia C2015 03 10.79591 11 01 23.38 +12 48 35.6 21.1 R D0516B18 Gaia C2015 03 10.79742 11 01 23.52 +12 48 33.8 21.5 R D0516B18 Gaia C2015 03 10.79817 11 01 23.57 +12 48 33.1 21.7 R D0516B18 Gaia C2015 03 10.79892 11 01 23.64 +12 48 32.2 21.1 R D0516B18 Gaia C2015 03 10.80043 11 01 23.72 +12 48 30.7 21.9 R D0516B18 … Observer details: B18 Terskol. Observers S. Velichko, M. Andreev, V. Godunova. Measurer M. Andreev. 2.0-m Ritchey-Chretien + CCD. ========================================= Fig. 2. Asteroid G01366, as seen with the aid of the 60-cm telescope (stacked image) Observations of newly detected asteroids In 2015, we start to observe asteroids discovered within the Gaia project. Objects have been selected from the list of recently discovered asteroids prepared by the Gbot team (gbot.obspm.fr/pub/ASTEROIDS/mostrecent.php). Ephemerides of the most bright and very recently detected asteroids have been computed using the following tools: http://www.projectpluto.com/fo.htm http://www.minorplanetcenter.net/iau/MPEph/NewObjEphems.html Asteroids have been observed down to V magnitude of 21 m , with individual exposure times of 60-180 seconds. There is a problem which concerns the processing of asteroid observations, because orbits of newly detected asteroids is not yet known to great precision. In fact, only observations that are close in time to those aquired with VST can be easily linked together, as the asteroid displacement relative to its background will be small. If the observations are performed over longer time spans (two days and more), it is difficult or even impossible to detect and identify these objects. =========================================================== COD B18 OBS M. Andreev, V. Godunova, O. Sergeev, N. Parakhin MEA M. Andreev TEL 0.6-m Cassegrain F/12.9 + CCD COM Observations of a new asteroid detected by the GBOT AC2 V_Godunova@bigmir.net NET NOMAD G01366 KC2015 05 21.87135 16 29 55.85 -24 36 00.3 19.6 R B18 G01366 KC2015 05 21.87460 16 29 55.68 -24 35 57.5 19.2 R B18 G01366 KC2015 05 21.87784 16 29 55.50 -24 35 55.9 19.3 R B18 G01366 KC2015 05 21.88108 16 29 55.32 -24 35 53.7 19.6 R B18 G01378 KC2015 05 21.84902 16 37 04.63 -25 33 41.5 19.4 R B18 G01378 KC2015 05 21.85334 16 37 04.34 -25 33 39.5 19.5 R B18 G01378 KC2015 05 21.85767 16 37 04.11 -25 33 37.2 19.5 R B18 G01378 KC2015 05 21.86201 16 37 03.87 -25 33 35.1 19.5 R B18 ===========================================================