Left panel: composite image of NGC 3503 and its environs. Red and green show emission at 8.13 μm (MSX) and 24 μm (MIPSGAL). The color scale goes from 1 × 10^-5 to 4 × 10^-5 W m^-2 sr^-1and from 27 to 100 MJy ster^-1, respectively. The white rectangle encloses the IR counterpart of NGC 3503 (IRK). Right panel: composite image of NGC 3503 . Red, green, and blue show emission at 8 μm (IRAC-GLIMPSE), 24, and 70 μm (MIPSGAL), respectively. Colors scales range from 40 to 500 MJy ster^-1(24 μm), from 300 to 2000 MJy ster^-1(70 μm), and from 30 to 400 MJy ster^-1(8 μm). The location of the members of Pis 17 is indicated with black crosses. MSX and 2MASS candidate YSOs are indicated with red and green crosses (see text).