The Canarias Einstein Ring: a Newly Discovered Optical Einstein Ring
  We report the discovery of an optical Einstein Ring in the Sculptor
constellation, IAC J010127-334319, in the vicinity of the Sculptor Dwarf
Spheroidal Galaxy. It is an almost complete ring ($\sim 300^{\circ}$) with a
diameter of $\sim 4.5\, {\rm arcsec}$. The discovery was made serendipitously
from inspecting Dark Energy Camera (DECam) archive imaging data. Confirmation
of the object nature has been obtained by deriving spectroscopic redshifts for
both components, lens and source, from observations at the $10.4$ m Gran
Telescopio CANARIAS (GTC) with the spectrograph OSIRIS. The lens, a massive
early-type galaxy, has a redshift of ${\rm z}=0.581$ while the source is a
starburst galaxy with redshift of ${\rm z}=1.165$. The total enclosed mass that
produces the lensing effect has been estimated to be ${\rm M_{tot}=(1.86 \pm
0.23) \,\cdot 10^{12}\, {\rm M_{\odot}}}$.
