A dynamical characterization of dark matter dominated dwarf galaxies from their observed effects on galactic disks ( i.e .
Galactoseismology ) has remained an elusive goal .
Here , we present preliminary results from spectroscopic observations of three clustered Cepheid candidates identified from K -band light curves towards Norma .
The average heliocentric radial velocity of these stars is \sim 156 km/s , which is large and distinct from that of the Galaxy ’ s stellar disk .
These objects at l \sim 333 ^ { \circ } and b \sim - 1 ^ { \circ } are therefore halo stars ; using the 3.6 ~ { } \micron period-luminosity relation of Type I Cepheids , they are at \sim 73 kpc .
Our ongoing I -band photometry indicates variability on the same time scale as the period determined from the K _ { s } -band light curve .
Distances determined from the K -band period-luminosity relation and the 3.6 \micron period-luminosity relation are comparable .
The observed radial velocity of these stars agrees roughly with predictions from dynamical models .
If these stars are indeed members of the predicted dwarf galaxy that perturbed the outer HI disk of the Milky Way , this would mark the first application of Galactoseismology .