  We report on VERITAS observations of the BL Lac object B2 1215+30 between
2008 and 2012. During this period, the source was detected at very high
energies (VHE; E > 100 GeV) by VERITAS with a significance of $8.9\sigma$ and
showed clear variability on time scales larger than months. In 2011, the source
was found to be in a relatively bright state and a power-law fit to the
differential photon spectrum yields a spectral index of $3.6 \pm
0.4_{\mathrm{stat}} \pm 0.3_{\mathrm{syst}}$ with an integral flux above 200
GeV of $(8.0 \pm 0.9_{\mathrm{stat}} \pm 3.2_{\mathrm{syst}}) \times 10^{-12}\,
\mathrm{cm}^{-2} \mathrm{s}^{-1}$. No short term variability could be detected
during the bright state in 2011. Multi-wavelength data were obtained
contemporaneous with the VERITAS observations in 2011 and cover optical
(Super-LOTIS, MDM, Swift-UVOT), X-ray (Swift-XRT), and gamma-ray (Fermi-LAT)
frequencies. These were used to construct the spectral energy distribution
(SED) of B2 1215+30. A one-zone leptonic model is used to model the blazar
emission and the results are compared to those of MAGIC from early 2011 and
other VERITAS-detected blazars. The SED can be well reproduced with model
parameters typical for VHE-detected BL Lacs.
