Photometric follow-up of RR Lyrae overdensities in the southern-hemisphere halo

The arrival of the SDSS revealed that the northern-hemisphere halo has plenty of substructures 
(e.g., the Field of Streams; Belokurov et al. 2006). The southern-hemisphere sky, on the other 
hand, remains a "terra incognita" where only recently some substructure candidates have 
been found, thanks to ongoing wide-field surveys. Extending the census of halo overdensities to 
the southern sky is important as these structures provide clues into the Milky Way's merger 
history. Very recently, more than 20 southern overdensity candidates were found, using RR 
Lyrae data from the Catalina Real-time Transient Survey (Torrealba et al, 2015). However, 
RR Lyrae stars comprise only a small fraction of the whole stellar populations in these 
overdensities. Accordingly, we have initiated a program to identify the underlying non-variable 
stars associated with each such candidate halo overdensity. In this contribution, our 
preliminary results for one of the most isolated overdensities will be presented (Scl01; Torrealba 
et al. 2015).