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In this paper, we construct the circular velocity curve of the Milky Way outto $\sim 30$ kpc, providing an updated model of the dark matter densityprofile. We derive precise parallaxes for 120,309 stars with a data-drivenmodel, using APOGEE DR17 spectra combined with Gaia DR3, 2MASS, and WISEphotometry. At outer galactic radii up to 30 kpc, we find a significantlyfaster decline in the circular velocity curve compared to the inner parts. Thisdecline is better fit with a cored Einasto profile with a slope parameter$0.91^{+0.04}_{-0.05}$ than a generalized Navarro-Frenk-White (NFW) profile.The virial mass of the best-fit dark matter halo profile is only$1.81^{+0.06}_{-0.05}\times10^{11}$ $M_{\odot}$, significantly lower than whata generalized NFW profile delivers. We present a study of the potentialsystematics, affecting mainly large radii. Such a low mass for the Galaxy isdriven by the functional forms tested, given that it probes beyond ourmeasurements. It is found to be in tension with mass measurements from globularclusters, dwarf satellites, and streams. Our best-fit profile also lowers theexpected dark matter annihilation signal flux from the galactic centre by morethan an order of magnitude, compared to an NFW profile-fit. In future work, wewill explore profiles with more flexible functional forms to more fullyleverage the circular velocity curve and observationally constrain theproperties of the Milky Way's dark matter halo.

The dark matter profile of the Milky Way inferred from its circular velocity curve