Electronic Telegram No. 5664
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
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Prepared using the Tamkin Foundation Computer Network


(44) NYSA
     K. Minker, Lowell Observatory; A. Conrad, Large Binocular Telescope
Observatory, Tucson; F. Pedichini, G. Li Causi, and S. Antoniucci, Istituto
Nazionale di Astrofisica, Rome; A. Berdeu, European Southern Observatory (ESO)
and Laboratoire d'Instrumentation et de Recherche en Astrophysique (LIRA),
Vitacura, Chile; M. Marsset, ESO, Garching; and B. Carry, Observatoire de la
Cote d'Azur, Nice, report that adaptive-optics R-band observations taken
with the 8.4-m Large Binocular Telescope reveal an unusual, highly concave,
possibly bilobate, shape for the main-belt asteroid (44) Nysa.  The
observation was made using the SHARK-VIS instrument during continous
monitoring from 2026 Feb. 15.1806 to 15.3229 UT.  If a bilobal interpretation
is correct, preliminary analysis indicates that at Feb. 15.2444 the projected
major and minor axes of the lobes were 98 x 26 and 52 x 64 (+/- 11) km, with a
projected inter-lobe angle of 110 +/- 10 degrees.  These observations are
consistent with reports of a highly elongated shape by Kaasalainen et al.
(2002, A.Ap. 383, L19) and Tanga et al. (2003, A.Ap. 401, 7330) using
photometric light curves and Hubble Space telescope imaging, respectively.
Both of those studies noted the possibility of a contact-binary morphology,
but neither confirmed nor denied its presence.  Additionally, Shepard et al.
(2008, Icarus 195, 220) presented radar observations from Arecibo Observatory
that suggested a concavity.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2026 CBAT
2026 February 23                 (CBET 5664)              Daniel W. E. Green