Electronic Telegram No. 3765 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network S/2012 (2577) 1 W. J. Merline, Southwest Research Institute (SwRI); P. M. Tamblyn, Binary Astronomy, LLC, Dillon, CO, U.S.A., and SwRI; B. D. Warner, Center for Solar System Studies, Landers, CA, USA; P. Pravec, Ondrejov Observatory; J. P. Tamblyn, Binary Astronomy, LLC, Dillon, CO, U.S.A.; C. Neyman, W. M. Keck Observatory; A. R. Conrad, Max Planck Institute for Astronomy; W. M. Owen, Jet Propulsion Laboratory; B. Carry, Institut de Mecanique Celeste et de Calcul des Ephemerides, Paris Observatory; J. D. Drummond, Starfire Optical Range, Air Force Research Laboratory, Kirtland Air Force Base, Albuquerque, NM, U.S.A.; C. R. Chapman and B. L. Enke, SwRI; W. M. Grundy, Lowell Observatory; C. Veillet, Large Binocular Telescope Observatory (LBTO); S. B. Porter, Lowell Observatory; C. Arcidiacono, Astronomical Observatory of Bologna, Istituto Nazionale di Astrofisica; J. C. Christou, LBTO; D. D. Durda, SwRI; A. W. Harris, "More Data!", La Canada, CA, USA; H. A. Weaver, Applied Physics Laboratory, Johns Hopkins University; C. Dumas, European Southern Observatory, Chile; D. Terrell, Sonoita Research Observatory and SwRI; and P. Maley, Houston, TX, USA, report the discovery, using the Keck II telescope (+ NIRC2 Laser-Guide-Star adaptive-optics system), of a second satellite of the Hungaria-type minor planet (2577) Litva. On 2012 June 22.3 UT, the satellite was found at p.a. 89 deg and separation 0".229 (projected separation 230 km). At that time, (2577) was 1.39 AU from the earth at magnitude V = 16.6. The satellite has been imaged in the K_p, H, and J bands. It was also detected on 2012 June 27, Aug. 11, and Aug. 16. Failure to detect it on 2012 July 15, despite excellent conditions, is now seen, in retrospect, to be due to being in conjunction with the primary. Follow-up observations were made at the Keck II telescope (+ LGS-AO) on 2013 Aug. 25 and 26 by Merline, Tamblyn, Conrad, and Tamblyn. Additional detections were made at the Large Binocular Telescope (adaptive secondary mirror and PISCES near-infrared camera at the "Right Front Bent" Gregorian focus) by Veillet and Arcidiacono on 2013 Oct. 12 and at the Keck II telescope (+ LGS-AO) by Grundy and Porter on 2013 Oct. 25, giving a total baseline of 490 days. The best-fit orbit analysis indicates that the third component has a semi-major axis of 378 km and an orbital period of 214 days. Despite the long baseline and the number of observational epochs, the phasing of the observations is such that a period of half this length cannot be ruled out. Either orbit would be among the longest periods known for main-belt binary/ multiple systems and would also be the most loosely bound. It resembles other wide binary systems discovered by this same group (cf. Durda et al. 2010, Proc. Lunar and Planet. Sci. Conf. 41, 2558; Jacobson et al., Ap.J., submitted, as viewable at website URL http://lanl.arxiv.org/abs/1311.4887). The third component is about 2.6 mag fainter than the combined brightness of the close inner pair. Using H magnitudes to scale the size of (2577) from other E-type objects of better-known size, the diameter of (2577) is estimated to be about 4 km, implying a size for the new satellite of 1.2 km. The first satellite of (2577) was discovered by Warner et al. (CBET 1715) in 2009, by lightcurve analysis, revealing eclipses/occultations by a close secondary, having an orbital period of 35.9 hr; their estimate of the size ratio was 0.35, meaning that the second component would be 1.4 km diameter, based on the 4-km assumption for (2577), above. This close inner pair is unresolvable in the imaging data reported above. Warner et al. (2009, Minor Planet Bull. 36, 165) suggested that a residual 5.7-hr lightcurve period may be due to rotation by a third body, an idea further bolstered by Pravec et al. (2012, Icarus 218, 125), who found that this period was still evident even when the secondary object was in eclipse. The observing program described here has given high priority to objects suspected of having satellites. To the authors' knowledge, S/2012 (2577) 1 is the only satellite to have been predicted prior to being found by targeted imaging. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2013 CBAT 2013 December 22 (CBET 3765) Daniel W. E. Green