The asteroid 1689 Floris-Jan is a small size object from the main asteroid belt. It was discovered in September 1930 by H. Van Gent. The diameter of 1689 Floris-Jan is estimated to be 9 to 27 km depending on the assumed albedo. In 1982 Schober et al. (1982) presented UBV photometry of this object, which revealed its unusually long period of rotation of 6.042 0.21 days. Typical periods of rotation of asteroids range from about 2 to about 20 hours. For many years this asteroid was considered to be one of the slowest rotators among minor planets. In 1997 our colleagues from the Astronomical Observatory of Adam Mickiewicz University, Pozna, selected 1689 Floris-Jan as a target for the observations in a long term program of CCD photometry of minor planets (Kryszczynska et al., 1996).
© European Southern Observatory (ESO) 1999
Online publication: March 1, 1999