scale of 1.24 arc seconds per pixel using an SBIG ST10XME. Flat, dark, and bias images were applied using MaximDL and photometry was done using MPO Canopus. All images were unfiltered. C15 (Cooney et al., 2015), K16 (Krugly et al., 2016), L20 (Larsen, J. A., et al. 2020. In preparation.), M07 (McMillan et al., 2007), P06 (Pravec et al., 2006), P14 (Pravec et al., 2014), P19 (Pravec et al., 2019), V17 (Vokrouhlický et al., 2017).

The data used in our analysis, obtained during six and five apparitions for 1999 KW4 and 2001 SL9, respectively, are summarized in Tables \[TableDataKW4\] and \[TableDataSL9\]. The references and descriptions of observational procedures of the individual observatories are summarized in Table \[TableObs\].

The data were reduced using the standard technique described in Pravec et al. (2006). By fitting a two-period Fourier series to data points outside mutual (occultation or eclipse) events, the rotational lightcurves of the primary (short-period) and the secondary (long-period), which are additive in intensities, were separated. The long-period component containing the mutual events and the secondary rotation lightcurve is then used for subsequent numerical modeling.

Numerical model {#NumModel}
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We constructed models of the two binary asteroids using the technique of Scheirich 