We present results from a multi-chord Pluto stellar occultation observed on 29 June 2015 from New Zealand and Australia .
This occurred only two weeks before the NASA New Horizons flyby of the Pluto system and serves as a useful comparison between ground-based and space results .
We find that Pluto ’ s atmosphere is still expanding , with a significant pressure increase of 5 \pm 2 % since 2013 and a factor of almost three since 1988 .
This trend rules out , as of today , an atmospheric collapse associated with Pluto ’ s recession from the Sun .
A central flash , a rare occurrence , was observed from several sites in New Zealand .
The flash shape and amplitude are compatible with a spherical and transparent atmospheric layer of roughly 3 km in thickness whose base lies at about 4 km above Pluto ’ s surface , and where an average thermal gradient of about 5 K km ^ { -1 } prevails .
We discuss the possibility that small departures between the observed and modeled flash are caused by local topographic features ( mountains ) along Pluto ’ s limb that block the stellar light .
Finally , using two possible temperature profiles , and extrapolating our pressure profile from our deepest accessible level down to the surface , we obtain a possible range of 11.9-13.7 \mu bar for the surface pressure .