Bostroem, Kyra; Walborn, Nolan; Crowther, Paul; Caballero-Nieves, Saida; Lennon, Daniel; Maíz Apellániz, Jesús
Massive Stars: From α to Ω, held 10-14 June 2013 in Rhodes, Greece; Online at http://a2omega-conference.net, id.56 (2013).
We display new (in some cases, the first ever) spatially resolved optical and UV spectroscopy of a number of early O-type stars in R136, the massive core cluster of 30 Doradus in the LMC. Some of them are of the earliest spectral types, O2-O3, which accompany the more luminous WN members that are the most massive stars known, near or exceeding 300~M_⊙ initially. These results are relevant to the very top of the IMF and to the structure and formation of starburst clusters. The data are from HST/STIS programs GO 12465/13052 (PI Crowther), in which the long slit was stepped across the inner 4 arcsec (1 parsec) of R136, yielding both optical photospheric and FUV stellar-wind spectra of at least 100 resolved members, many of them for the first time. The optical data were obtained at 4 epochs to support eventual radial-velocity detection of spectroscopic binaries. This program vitally complements the VLT-FLAMES Tarantula Survey of the wider stellar content of 30 Doradus, by adding that of the massive core cluster, which is inaccessible to such observations from the ground. These combined datasets will provide unprecedented information about massive stellar evolution and starbursts.