  Aims: Very Long Baseline Interferometry yields physical constraints on the
compact radio emission of young stellar objects. At the same time, such
measurements can be used for precise astrometric measurements of parallaxes and
proper motions. Here, we aimed to make the first detections of very compact
radio emission from class I protostars in the Corona Australis star-forming
region. Methods: We have used the Long Baseline Array (LBA) to observe the
protostars IRS 5 and IRS 7 in the Corona Australis star-forming region in three
separate epochs Results: We report the first firm radio detection of a class I
protostar using very long baseline interferometry. We have detected the
previously known non-thermal source IRS 5b, part of a binary system. IRS 5a and
IRS 5N were undetected, as were all sources in the IRS 7 region. Conclusions:
These results underline the unusual nature of IRS 5b as a genuine protostar
with confirmed non-thermal radio emission. Also, these observations highlight
the potential of the LBA as a tool to provide precision astrometric
measurements of individual young stellar objects in southern star-forming
regions that are not accessible to the Very Long Baseline Array in the northern
hemisphere.
