Understanding the nature of the blazar CGRaBS~J0211$+$1051
  The source CGRaBS~J0211$+$1051 (MG1 J021114+1051, z=0.20) flared up on 2011
January 23 in high-energy $\gamma$-rays as reported by {\it Fermi}/LAT. This
event was followed by the increased activity at the UV, optical and radio
frequencies as detected by the observing facilities worldwide. The source also
showed a high and variable optical polarization based on which it was proposed
to be a low-energy peaked BL Lac Object (LBL). Present work reports first
comprehensive multi-wavelength study of this source using data in the radio,
optical, UV, X- and $\gamma$-rays and optical polarization. Using these
multi-wavelength data on the source, we have estimated various parameters and
verified it's classification vis-a-vis blazar sequence. Multi-waveband
light-curves are used to discuss flaring events of 2011 January in an attempt
to address the nature of the source and pinpoint the possible physical
processes responsible for the emission. The light-curves show variations in the
high energy $\gamma$-rays to be correlated with X-ray, UV and optical
variations, perhaps indicating to their co-spatial origin. Our optical data,
quasi-simultaneous with UV (Swift-UVOT) and X-ray (Swift-XRT) data, enabled us
to trace low energy (Synchrotron) component of the spectral energy distribution
(SED) for CGRaBS J0211+1051, for the first time. The SED shows the synchrotron
peak to lie at $\sim 1.35\times10^{14}$~Hz, confirming CGRaBS~J0211+1051 to be
an LBL. Some other parameters, such as local magnetic field ($\sim 5.93 $
Gauss) and black hole mass ($\sim 2.4 \times 10^{8} M_{\odot}$) are also
estimated which are in agreement with their typical values for the blazars.
Based on the present study, identification of the Fermi/LAT source, 2FGL
J0211.2+1050, with its BL Lac counterpart CGRaBS J0211+1051 is confirmed.
