| Abstract | We present BVRI CCD photometry of ~600 stars in the central region of a resolved spiral galaxy NGC 1560 which is seen almost edge-on, apparently located in the IC 342 group. The V - (B - V) diagram shows a dominant group of significantly reddened blue plume stars consisting of young massive main-sequence and evolved blue supergiant stars. The tip of the blue plume is found to be at V ~ 21 mag and (B-V)~0.4 mag. The I -(R-I) diagram shows a large group of red supergiants the brightest of which are extending to I~19.5 mag at (R-I)~ 1.1 mag. The logarithmic slope of the V luminosity function of the blue plume stars is 0.69 +/- 0.10, similar to that for other nearby galaxies. The mean color of the blue plume stars is <(B - V)> = 0.25 +/- 0.03 mag. The total reddening, including both foreground and internal reddening, is estimated from the mean color of the blue plume stars, to be E(B - V) = 0.40 +/- 0.10 mag, whereas the foreground reddening based on the H I column density and faint galaxy counts is E(B-V) = 0.16 mag. Combining our results with those in the literature, we have obtained distance estimates using four methods: brightest blue stars [(m -M)_0_ = 27.11 mag], brightest red stars [(m-M)_0_ = 27.02 mag], B-band Tully-Fisher relation [(m-M)_0_ = 26.96 mag], and H-band Tully-Fisher relation [(m-M)_0_ = 26.86 mag]. These four estimates agree very well. Taking the average of these four estimates, we obtain a value for the true distance modulus to NGC 1560, (m-M)_0_ = 27.0 +/- 0.1 mag, corresponding to a distance of 2.5+/-0.1 Mpc. |
