On the serendipitous discovery of a Li-rich giant in the globular
  cluster NGC 362
  We have serendipitously identified the first lithium-rich giant star located
close to the red giant branch bump in a globular cluster. Through
intermediate-resolution FLAMES spectra we derived a lithium abundance of
A(Li)=2.55 (assuming local thermodynamical equilibrium), which is extremely
high considering the star's evolutionary stage. Kinematic and photometric
analysis confirm the object as a member of the globular cluster NGC 362. This
is the fourth Li-rich giant discovered in a globular cluster but the only one
known to exist at a luminosity close to the bump magnitude. The three previous
detections are clearly more evolved, located close to, or beyond the tip of
their red giant branch. Our observations are able to discard the accretion of
planets/brown dwarfs, as well as an enhanced mass-loss mechanism as a formation
channel for this rare object. Whilst the star sits just above the cluster bump
luminosity, its temperature places it towards the blue side of the giant branch
in the colour-magnitude diagram. We require further dedicated observations to
unambiguously identify the star as a red giant: we are currently unable to
confirm whether Li production has occurred at the bump of the luminosity
function or if the star is on the pre zero-age horizontal branch. The latter
scenario provides the opportunity for the star to have synthesised Li rapidly
during the core helium flash or gradually during its red giant branch ascent
via some extra mixing process.
