Using HST WFPC2 images , we have obtained U,B,V,I, and H \alpha photometry for 76 star clusters in the nuclear star-forming ring of the barred spiral galaxy NGC 4314 .
These clusters are likely associated with an inner Inner Lindblad Resonance , or IILR .
The blue colors and H \alpha emission for most of these clusters imply very young ages of 1-15 Myr .
Age estimates based on several reddening-free parameters indicate that the present epoch of star formation has lasted at least 30 Myr .
By estimating the masses of stars in the clusters and comparing with the H \alpha luminosity , we conclude that a significant fraction of ongoing star formation in the nuclear ring of NGC 4314 occurs in clusters .
The cluster masses identify these as young open clusters , not young globular clusters .
Further out in the galaxy , just exterior to the ring of young stars , previous ground-based observations revealed two symmetric stellar spiral arms which may be associated with an outer Inner Lindblad Resonance , or OILR .
With our HST data , we have revealed part of this structure and its colors in more detail .
The spiral arm colors are consistent with stellar ages between 40 and 200 Myr .
The age difference between the inner ring of young stars ( IILR ) and the larger oval-like feature containing the blue arms ( OILR ) supports an interpretation of the morphology of the nuclear region of NGC 4314 that requires a reservoir of gas that becomes more compact over time .
We speculate that as the gas distribution becomes more centrally concentrated , it interacts with these two resonances .
Each resonance triggers star formation , resulting in two distinct epochs of star formation .