We present moderate-resolution spectroscopic observations of red supergiants ( RSGs ) in the low-metallicity Local Group galaxies NGC 6822 ( Z = 0.4 Z _ { \odot } ) and Wolf-Lundmark-Melotte ( WLM ; Z = 0.1 Z _ { \odot } ) .
By combining these observations with reduction techniques for multislit data reduction and flux calibration , we are able to analyze spectroscopic data of 16 RSGs in NGC 6822 and spectrophotometric data of 11 RSGs in WLM .
Using these observations we determine spectral types for these massive stars , comparing them to Milky Way and Magellanic Clouds RSGs and thus extending observational evidence of the abundance-dependent shift of RSG spectral types to lower metallicities .
In addition , we have uncovered two RSGs with unusually late spectral types ( J000158.14-152332.2 in WLM , with a spectral type of M3 I , and J194453.46-144552.6 in NGC 6822 , with a spectral type of M4.5 I ) and a third RSG ( J194449.96-144333.5 in NGC 6822 ) whose spectral type has varied from a M2.5 in 1997 to a K5 in 2008 .
All three of these stars could potentially be members of a recently-discovered class of extreme RSG variables .