Madison R. LeBlanc, Tim M. Johns, Todd J. Henry, Kenneth J. Slatten, Jennifer G. Winters, Wei-Chun Jao, Aman Kar, Michele L. Silverstein, Eliot Halley Vrijmoet, Casey Rush, Andrew A. Couperus
We present the RMSTAR (RECONS M STAR) catalog, a 25 pc volume-limited and effectively volume-complete sample of the nearest 3352 M dwarf systems and their 305 wide stellar and 9 brown dwarf companions. RMSTAR has been created using only results from \textit{Gaia} Data Releases 3 (GDR3) and 2 (GDR2), \textit{Hipparcos}, and ground-based discoveries of M dwarf systems that are not available in the space-based results. The wide companions are identified using only results from GDR3 and GDR2, and have separations $ρ\ge0.''46$. There are 291 primaries with stellar companions, yielding a multiplicity rate of 8.68$\pm$0.49\% for these widely separated systems, with a rate of 6.86$\pm$0.44\% for projected separations $s\geq30$ au, where the sample of stellar companions is complete except perhaps for a few fringe cases. It is shown that the rate of stellar companions increases from the search limit of 30,000 au down to separations of 30 au, with a large set of companions to be characterized at closer separations in future work. We determine luminosity and mass functions for all stellar red dwarfs and their wide secondaries, finding that the luminosity function displays a classic turnover at $M_G\sim11$, whereas the mass function is described by an exponential function that rises from 0.60 M$_{\odot}$ to the end of the stellar main sequence at 0.075 M$_{\odot}$. We assess the large population of close, unresolved companions to M dwarfs by analyzing several \textit{Gaia} parameters, identifying 1089 (30\%) individual sources as having at least one of these elevated unresolved companion indication parameters.