IS THE SUN LOCATED NEAR THE COROTATION CIRCLE

The line-of-sight velocity field of Cepheids was analysed in terms of a disk galaxy model perturbed by spiral density waves in order to esti mate the parameters of the galactic rotation curve and the free parame ters of density waves. It was shown that: 1) the Sun is located near t he corotation circle because the angular rotation velocity of the Gala xy Omega. approximate to 26.0 km s(-1) kpc(-1) (Kerr & Lynden-Bell, 19 86; Dambis, Mel'nik & Rastorguev, 1995) is close to that of the spiral pattern Omega(p) approximate to 28.1 +/- 2.0 km s(-1) kpc(-1) and the corotation radius R-c approximate to 7.2 +/- 1.3 kpc (we adopt the ga lactocentric distance of the Sun R. approximate to 7.5 kpc); 2) the sp iral pitch angle i approximate to -6.8 degrees +/- 0.7 degrees; 3) the Sun is at the spiral wave phase chi. approximate to 290 degrees +/- 1 6 degrees; 4) Oort's constant A approximate to 20.9 +/- 1.2 km s(-1) k pc(-1); the second term in the expansion of the galactic rotation velo city is R.Omega.'' approximate to 13.3 +/- 3.1 km s(-1) kpc(-2).