CCD photometry of asteroids (4197) 1982 TA and 1997 LY4

We present results of our photometric observations of the Apollo asteroid (4197) 1982 TA and the Mars-crosser 1997 LY4. Their synodic rotation periods (3.53802±0.00005) and (46.07±0.02) h, respectively, have been derived. The fast rotation of (4197) suggests a lower limit of the bulk density of 1.1 g/cm3. The mean diameter of (4197) is likely in the range 3–6 km. The present knowledge does not support a possibility that (4197) is an extinct cometary nucleus as suggested from its orbit. The smaller (1.4–3 km), slowly-rotating asteroid 1997 LY4 is an elongated object with the equatorial axis ratio ≥1.8.