Spectral Energy Distribution of Blue Stragglers in the core of 47
  Tucanae
  We have constructed the Spectral Energy Distributions (SEDs) of a sample of
Blue Straggler Stars (BSSs) in the core of the globular cluster 47 Tucanae,
taking advantage of the large set of high resolution images, ranging from the
ultraviolet to the near infrared, obtained with the ACS/HRC camera of the
Hubble Space Telescope. Our final BSS sample consists of 22 objects, spanning
the whole color and magnitude extension of the BSS sequence in 47 Tucanae. We
fitted the BSS broadband SEDs with models to derive temperature, surface
gravity, radius, luminosity and mass. We show that BSSs indeed define a mass
sequence, where the mass increases for increasing luminosity. Interestingly,
the BSS masses estimates from the SED fitting turn out to be comparable to
those derived from the projection of the stellar position in the
color-magnitude diagram onto standard star evolutionary tracks. We compare our
results with previous, direct mass estimates of a few BSSs in 47 Tucanae. We
also find a couple of supermassive BSS candidates, i.e., BSSs with a mass
larger than twice the turn-off mass, the formation of which must have involved
more than two progenitors.
