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The methoxy (CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$O) radical has attracted a great deal of attention in the literature due to its unique spectroscopy, as well as its importance as a reactive intermediate in combustion and atmospheric chemistry. In this study, we employ CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$O as a dynamical probe of the photodissociation dynamics of methyl nitrate, CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$ONO$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$, at 193 nm. Rotationally-resolved spectra of the CH$3$O photoproduct were recorded in the $A2A1\backslash relbarX2E$ system under both nascent and jet-cooled conditions using laser-induced fluorescence (LIF) spectroscopy. CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$O $A2A1\backslash relbarX2E$ transitions could be simulated effectively using known spectroscopic constants at the lowest temperatures achieved under jet-cooled conditions. Spectra recorded at warmer temperatures are being used to refine reported spectroscopic constants. Under nascent conditions, transitions were observed from the vibrationless level of CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$O ($X2E$) as well as with C$\backslash relbar$O stretch vibrational excitation, and the vibrational branching ratio is determined. The rotational excitation of these vibrational bands was fit to a Boltzmann distribution to extract nascent rotational temperatures. The experimental data indicate that the CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$O fragment is produced with minimal internal energy (1% of the available energy) following photodissociation of CH$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$ONO$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ at 193 nm.