NGC147 and NGC185, paired satellites of the Andromeda galaxy, possess the same order of mass and analogous structures, but they show dierent star formation and different amounts of interstellar gas and dust. Therefore, we present the first reconstruction of the star formation history of NGC147 and NGC185. Asymptotic Giant Branch stars are highly evolved stars that are brightest in K-band. This maximum K-band magnitude is related to the birth mass of stars. As a result, we have found a 9.9 Gyrold single star formation epoch for NGC185 followed by relatively continuous star formation. NGC147, however, has passed through two star formation episodes; one is as old as ~6 Gyr and the other is as recent as 850 Myr. Asymptotic Giant Branch stars are also important dust factories; by fitting Spectral Energy Distributions to observed near and mid infrared data for each star, we were able to measure the dust production rates of individual stars; on order of 10-5M⊙yr-1. Hence, we estimate the total mass entering the interstellar medium to be 1.06 X 10-4M⊙ yr-1 and 2.89 X 10-4M⊙ yr-1 for NGC147 and NGC185.

We present B VRI CCD surface photometry for the central (6'.35 ×6'.35) regions of the dwarf elliptical galaxies NGC 185 and NGC 205 in the Local Group. Surface brightness profiles of NGC 185 (R<225") and NGC 205 (R<186") show excess components in the central regions. The colors of NGC 185 get bluer inward at R<25", while they remain constant at R ≥ 25". The colors of NGC 205 get bluer inward at 1"<R<50", and remain flat outside. Our photometry, supplemented by the photometry based on the far-ultraviolet and visual images of the HST archive data, shows that there is an inversion of color at the very nucleus region (at about 1"). The implications of the redder color of the core part of the nucleus compared with neighboring regions are discussed. The amount of the excess components in the central regions of these galaxies is estimated to be ≈10 5 L⊙. Distributions of dust clouds in the central regions of the two galaxies are also investigated.