Observation of a narrow meson decaying to<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi>γ</mml:mi></mml:math>at a mass of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>2.458</mml:mn><mml:mi/><mml:mi mathvariant="normal">GeV</mml:mi><mml:mrow><mml:msup><mml:mrow><mml:mo>/</mml:mo><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>

A narrow state, which we label ${D}_{\mathrm{sJ}}{(2458)}^{+},$ with a mass $2458.0\ifmmode\pm\else\textpm\fi{}1.0(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.0(\mathrm{syst})\mathrm{MeV}{/c}^{2},$ is observed in the inclusive ${D}_{s}^{+}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$ mass distribution in $91{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ storage ring. The observed width is consistent with the experimental resolution. The data favor decay through ${D}_{s}^{*}{(2112)}^{+}{\ensuremath{\pi}}^{0}$ rather than through ${D}_{\mathrm{sJ}}^{*}{(2317)}^{+}\ensuremath{\gamma}.$ An analysis of ${D}_{s}^{+}{\ensuremath{\pi}}^{0}$ data accounting for the influence of the ${D}_{\mathrm{sJ}}{(2458)}^{+}$ produces a ${D}_{\mathrm{sJ}}^{*}{(2317)}^{+}$ mass of $2317.3\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.8(\mathrm{syst})\mathrm{MeV}{/c}^{2}.$