  We report the detection of a very low mass star (VLMS) companion to the
primary star 1SWASPJ234318.41+295556.5A (J2343+29A), using radial velocity (RV)
measurements from the PARAS (PRL Advanced Radial-velocity Abu-sky Search) high
resolution echelle spectrograph. The periodicity of the single-lined eclipsing
binary (SB1) system, as determined from 20 sets of RV observations from PARAS
and 6 supporting sets of observations from SOPHIE data, is found to be 16.953 d
as against the 4.24 d period reported from SuperWasp photometry. It is likely
that inadequate phase coverage of the transit with SuperWasp photometry led to
the incorrect determination of the period for this system. We derive the
spectral properties of the primary star from the observed stellar spectra: Teff
= 5125 +/- 67 K, [Fe/H] = 0.1 +/- 0.14 and log g = 4.6 +/- 0.14, indicating a
K1V primary. Applying the Torres relation to the derived stellar parameters, we
estimate a primary mass 0.864 +/- 0.097 M_sun and a radius of 0.854 +/- 0.050
R_sun. We combine RV data with SuperWASP photometry to estimate the mass of the
secondary, M_B = 0.098 +/- 0.007 M_sun, and its radius, R_B = 0.127 +/- 0.007
R_sun, with an accuracy of around 7%. Although the observed radius is found to
be consistent with the Baraffe's theoretical models, the uncertainties on the
mass and radius of the secondary reported here are model dependent and should
be used with discretion. Here, we establish this system as a potential
benchmark for the study of VLMS objects, worthy of both photometric follow-up
and the investment of time on high-resolution spectrographs paired with
large-aperture telescopes.
