A blue stellar link between the Magellanic Clouds

Three pairs of UK Schmidt plates of selected fields between the Magellanic Clouds have been processed using the APM facility in Cambridge. Color- magnitude diagrams obtained from the plate pairs revealed the presence of blue main-sequence stars between the wing of the SMC and the western halo of the LMC. The spatial distribution of these blue stars, B(J) - R less than 0.0, shows that many of them are in aggregates and newly identified clusters, stretching from an area surrounding and including the SMC wing tip all the way across to the LMC halo. Spectroscopic observations confirmed that the stars are indeed OB stars at a distance of about 50 kpc with radial velocities consistent with cloud membership. The number and distribution of horizontal branch stars identified in the same area also support the conclusion that the SMC wing is really the brightest section of the stellar link between the SMC and LMC. All of the individual blue stellar aggregates, including the region around the tip of the SMC wing, appear to have been formed about 10 to the 8th yr ago suggesting a common origin for all these features. (Author)