Program: GS-2020A-FT-201

The formation of a high-mass star generates a stellar cluster. Whether this is an unavoidable outcome of the formation process is still unclear but certainly not excluded by theory. We propose to scrutinize the apparent isolated nature of a O3If* 100 solar mass star shown by Gaia astrometry (Kalari et al. 2019). Using medium resolution GMOS spectra, we plan to assess the radial velocity to completely exclude (or demonstrate) a runaway/walkaway scenario. Additional deep JHKs imaging can identify any previously unappreciated stellar overdensities or young clusters surrounding RFS8 (or not). Combined, our observations will be telling on the formation scenario of what is currently the best isolated massive star formation candidate, providing crucial evidence for the current debate on massive star formation.