Electronic Telegram No. 1686 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html eta CARINAE E. Fernandez-Lajus, Observatorio Astronomico de La Plata, Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, on behalf of the "La Plata eta Carinae monitoring group" (cf. CBET 1654), reports that eta Car has reached the minimum related to the 2009.0 event in the U, B, V, R, and I bands around 2009 Jan. 26-27, as determined from CCD observations that were obtained in Argentina using the 0.8-m "Virpi S. Niemela" telescope at La Plata Observatory (as detailed by Fernandez-Lajus et al. 2009, A.Ap. 493, 1093) and the 0.6-m "Helen Sawyer Hogg" telescope at Complejo Astronomico El Leoncito. The minimum was reached after about a 0.15-mag dip from maximum in the BVRI bands and 0.23 mag in U. The BVRI light curves are available at the following website URL: http://etacar.fcaglp.unlp.edu.ar/. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 February 5 (CBET 1686) Daniel W. E. Green