The Low-Frequency Array radio telescope discovered the $707$ Hz binary millisecond pulsar (MSP) J0952$-$0607 in a targeted radio pulsation search of an unidentified $textit{Fermi}$ gamma-ray source. This source shows a weak energy flux of $F_gamma = 2.6 times 10^{-12},text{erg},text{cm}^{-2},text{s}^{-1}$ in the energy range between $100,text{MeV}$ and $100,text{GeV}$. Here we report the detection of pulsed gamma-ray emission from PSR$,$J0952$-$0607 in a very sensitive gamma-ray pulsation search. The pulsars rotational, binary, and astrometric properties are measured over seven years of $textit{Fermi}$-Large Area Telescope data. For this we take into account the uncertainty on the shape of the gamma-ray pulse profile. We present an updated radio-timing solution now spanning more than two years and show results from optical modeling of the black-widow-type companion based on new multi-band photometric data taken with HiPERCAM on the Gran Telescopio Canarias on La Palma and ULTRACAM on the New Technology Telescope at ESO La Silla. PSR$,$J0952$-$0607 is now the fastest-spinning pulsar for which the intrinsic spin-down rate has been reliably constrained ($dot{P}_text{int} lesssim 4.6 times 10^{-21},text{s},text{s}^{-1}$). The inferred surface magnetic field strength of $B_text{surf} lesssim 8.2 times 10^{7},text{G}$ is among the ten lowest of all known pulsars. This discovery is another example of an extremely fast spinning black-widow pulsar hiding within an unidentified $textit{Fermi} gamma-ray source. In the future such systems might help to pin down the maximum spin frequency and the minimum surface magnetic field strength of MSPs.
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