  A star's obliquity with respect to its planetary system can provide us with
insight into the system's formation and evolution, as well as hinting at the
presence of additional objects in the system. However, M dwarfs, which are the
most promising targets for atmospheric follow-up, are underrepresented in terms
of obliquity characterization surveys due to the challenges associated with
making precise measurements. In this paper, we use the extreme-precision radial
velocity spectrograph MAROON-X to measure the obliquity of the late M dwarf
TRAPPIST-1. With the Rossiter-McLaughlin effect, we measure a system obliquity
of $-2^{+17}_{-19}$ degrees and a stellar rotational velocity of 2.1 $\pm$ 0.3
km s$^{-1}$. We were unable to detect stellar surface differential rotation,
and we found that a model in which all planets share the same obliquity was
favored by our current data. We were unable to make a detection of the
signatures of the planets using Doppler tomography, which is likely a result of
the both the slow rotation of the star and the low SNR of the data. Overall,
TRAPPIST-1 appears to have a low obliquity, which could imply that the system
has a low primordial obliquity. It also appears to be a slow rotator, which is
consistent with past characterizations of the system and estimates of the
star's rotation period. The MAROON-X data allow for a precise measurement of
the stellar obliquity through the Rossiter-McLaughlin effect, highlighting the
capabilities of MAROON-X and its ability to make high-precision RV measurements
around late, dim stars.
