Electronic Telegram No. 23 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://cfa-www.harvard.edu/iau/cbat.html eta CARINAE P. A. Whitelock, F. Marang, and L. Crause, South African Astronomical Observatory, report that observations show that the anticipated fading of eta Car (cf. IAUC 8154) at infrared wavelengths (JHKL) started between June 19 (L) and June 24 (J). Following the discussion of Feast et al. (2001, M.N.R.A.S. 322, 741) infrared minimum can be expected around July 13. NOTE: These 'Central Bureau Electronic Telegrams' are intended to be preliminary announcements of items that later appear in the formal IAU Circulars. Citations should normally be made to IAUCs rather than to CBETs. (C) Copyright 2003 CBAT 2003 June 28 (CBET 23) Kyle E. Smalley