I will report on new X-ray spectropolarimetric observations from the recently launched
Imaging X-ray Polarimetry Explorer (IXPE) of the ultracompact low-mass X-ray binary
system 4U 1626-67. I will also report on supplementary observations taken by NICER and
Chandra/HETGS around the IXPE observation window. I will present energy-resolved and
pulse phase-resolved spectropolarimetric 2-8 keV IXPE observations of 4U 1626-67 and
discuss implications for our understanding of accretion geometries in accreting
pulsars. NICER provided complementary spectral and timing results over the 0.3-10 keV
band, with an emphasis on the soft band; Chandra/HETGS allowed for detailed
characterization of the plasma in the accretion disk. 4U 1626-67 is an interesting
system as it hosts a slowly spinning accretion-powered pulsar (~7.7 s) with a strong
magnetic field (B ~ 10^12 G) in a ~42 minute ultracompact orbit around a very low mass
hydrogen-depleted companion. It has exhibited two episodes of long-term torque reversals
in 1990 and 2008, and it is currently in the spin-up state; the pulse profiles also
exhibit strong energy dependence. The quiescent state is also occasionally punctured by
>100 s-long flaring episodes. In addition, the system hosts a highly
collisionally-ionized plasma in the accretion disk and complex emission line phenomena
around 1 keV (attributed to Ne X and O VIII).