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We report on the VERITAS discovery of very-high-energy (VHE) gamma-ray emission above 200 GeV from the high-frequency-peaked BL Lac object RXJ0648.7+1516 (GBJ0648+1516), associated with 1FGL J0648.8+1516. The photon spectrum above 200 GeV is fit by a power law dN/dE = F0(E/E0)-Gamma with a photon index of 4.4 ± 0.8stat ± 0.3syst and a flux normalization F0 of (2.3± 0.5stat ±1.2sys)×10^-11 TeV^-1cm^-2s^-1 with E0 = 300 GeV. No VHE variability is detected during VERITAS observations of RXJ0648.7+1516 between 2010 March 4 and April 15. Following the VHE discovery, the optical identification and spectroscopic redshift were obtained using the Shane 3–m Telescope at the Lick Observatory, showing the unidentified object to be a BL Lac type with a redshift of z = 0.179. Broadband multiwavelength observations contemporaneous with the VERITAS exposure period can be used to sub-classify the blazar as a high-frequency-peaked BL Lac (HBL) object, including data from the MDM observatory, Swift -UVOT and XRT, and continuous monitoring at photon energies above 1 GeV from the Fermi Large Area Telescope (LAT). We find that in the absence of undetected, high-energy rapid variability, the one-zone synchrotron self-Compton model (SSC) overproduces the high-energy gamma-ray emission measured by the Fermi -LAT over 2.3 years. The SED can be parameterized satisfactorily with an external-Compton or lepto-hadronic model, which have two and six additional free parameters, respectively, compared to the one-zone SSC model. Fil: Aliu, E.. Columbia University; Estados Unidos Fil: Aune, T.. University of California; Estados Unidos Fil: Beilicke, M.. University of Washington; Estados Unidos Fil: Benbow, W.. Harvard-Smithsonian Center for Astrophysics; Estados Unidos Fil: Bottcher, M.. Ohio University; Estados Unidos Fil: Bouvier, A.. University of California; Estados Unidos Fil: Bradbury, S. M.. University of Leeds; Reino Unido Fil: Buckley, J. H.. Washington University; Estados Unidos Fil: Bugaev, V.. Washington University; Estados Unidos Fil: Cannon, A.. University College Dublin,; Irlanda Fil: Cesarini, A.. National University of Ireland Galway; Irlanda Fil: Ciupik, L.. Adler Planetarium and Astronomy; Estados Unidos Fil: Connolly, M. P.. National University of Ireland Galway; Irlanda Fil: Cui, W.. Purdue University; Estados Unidos Fil: Decerprit, D.. Desy; Alemania Fil: Dickherber, R.. Washington University; Estados Unidos Fil: Duke, C.. Grinnell College; Estados Unidos Fil: Errando, M.. Columbia University; Estados Unidos Fil: Falcone, A.. Pennsylvania State University; Estados Unidos Fil: Feng, Q.. Purdue University; Estados Unidos Fil: Finnegan, G.. University of Utah; Estados Unidos Fil: Fortson, L.. University of Minnesota; Estados Unidos Fil: Furniss, A.. University of California; Estados Unidos Fil: Galante, N.. Harvard-Smithsonian Center for Astrophysics; Estados Unidos Fil: Gall, D.. University of Iowa; Estados Unidos Fil: Gillanders, G. H.. National University of Ireland Galway; Irlanda Fil: Godambe, S.. University of Utah; Estados Unidos Fil: Griffin, S.. McGill University; Canadá Fil: Grube, J.. Adler Planetarium and Astronomy Museum; Estados Unidos Fil: Pichel, Ana Carolina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: The Veritas Collaboration.

We present results of five years of optical (UBVRI) observations of the very-high-energy gamma-ray blazar 1ES 1011+496 at the MDM Observatory. We calibrated UBVRI magnitudes of five comparison stars in the field of the object. Most of our observations were done during moderately faint states of 1ES 1011+496 with R > 15.0. The light curves exhibit moderate, closely correlated variability in all optical wavebands on time scales of a few days. A cross-correlation analysis between optical bands does not show significant evidence for time lags. We find a positive correlation (Pearson's r = 0.57; probability of non-correlation P(>r) ~ 4e-8) between the R-band magnitude and the B - R color index, indicating a bluer-when-brighter trend. Snap-shot optical spectral energy distributions (SEDs) exhibit a peak within the optical regime, typically between the V and B bands. We find a strong (r = 0.78; probability of non-correlation P (>r) ~ 1e-15) positive correlation between the peak flux and the peak frequency, best fit by a relation $��F_��^{\rm pk} \propto ��_{\rm pk}^k$ with k = 2.05 +/- 0.17. Such a correlation is consistent with the optical (synchrotron) variability of 1ES 1011+496 being primarily driven by changes in the magnetic field., Accepted for publication in ApJ. 16 pages, including 7 figures