  The process of accretion in classical T Tauri stars (CTTSs) has been observed
to vary on different timescales. Studying this variability is vital to
understanding a star's evolution and provides insight into the complex
processes at work within. Understanding the dichotomy between continuum veiling
and emission line veiling is integral to accurately measuring the amount of
veiling present in stellar spectra. Here, 15 roughly consecutive nights of
optical spectroscopic data from the spectropolarimeter ESPaDOnS are utilised to
characterise the short-term accretion activity in the CTTS, RU Lup, and
investigate its relationship with the veiling in the LiI 6707A absorption line.
The accretion-tracing HI Balmer series emission lines were studied and used to
obtain the accretion luminosity (Lacc) and mass accretion rate (Macc) for each
night, which vary by a factor of ~2 between the brightest and dimmest nights.
We also measured the veiling using multiple photospheric absorption lines (NaI
5688A, MnI 6021A, and LiI 6707A) for each night. We find the LiI 6707A line
provides measurements of veiling that produce a strong, positive correlation
with Lacc in the star. When corrected for Li depletion, the average veiling
measured in the LiI 6707A line is r_LiI(avg)~3.25+/-0.20, which is consistent
with the other photospheric lines studied (r_avg~3.28+/-0.65). We measured
short timescale variability in the Lacc and Macc that are intrinsic and not due
to geometric effects. Upon comparing the changes in veiling and Lacc, we find a
strong, positive correlation. This study provides an example of how this
correlation can be used as a tool to determine whether a measured variability
is due to extinction or an intrinsic change in accretion. As the determination
of veiling is an independent process from measuring Lacc, their relationship
allows further exploration of accretion phenomena in young stars.
