A Novel Survey for Young Substellar Objects with the W-band filter III:
  Searching for very low mass brown dwarfs in Serpens South and Serpens Core
  We present CFHT photometry and IRTF spectroscopy of low-mass candidate
members of Serpens South and Serpens Core ($\sim$430 pc, $\sim$0.5 Myr),
identified using a novel combination of photometric filters, known as the
W-band method. We report SC182952+011618, SS182959-020335 and SS183032-021028
as young, low-mass Serpens candidate members, with spectral types in the range
M7-M8, M5-L0 and M5-M6.5 respectively. Best-fit effective temperatures and
luminosities imply masses of $<$ 0.12M$_{\odot}$ for all three candidate
cluster members. We also present Hubble Space Telescope imaging data (F127M,
F139M and F850LP) for six targets in Serpens South. We report the discovery of
the binary system SS183044-020918AB. The binary components are separated by
$\approx$45 AU, with spectral types of M7-M8 and M8-M9, and masses of 0.08-0.1
and 0.05-0.07M$_{\odot}$. We discuss the effects of high dust attenuation on
the reliability of our analysis, as well as the presence of reddened background
stars in our photometric sample.
