We report on X-ray and TeV \gamma -ray observations of the pulsar/Be star binary PSR J2032+4127/MT91 213 .
PSR J2032+4127 is a 143-ms \gamma -ray pulsar which shares a long period ( 45-50 year ) and highly eccentric orbit with the massive Be star MT91 213 .
TeV \gamma -ray emission was detected from the binary following a coordinated observing campaign over the fall 2017 periastron with VERITAS , MAGIC , and X-ray monitoring with Swift -XRT .
The discovery of this \gamma -ray binary makes it just the second such source known to contain a pulsar as the compact object .
We report on over 100 hours of extensive TeV observations across the periastron passage , which reveal variations in the TeV flux by an order of magnitude over time scales of days .
The X-ray flux was also found to be highly variable , although it was not directly correlated with the TeV flux .
These observations present serious challenges to existing models of the system , which will require significant revisions .
We also discuss the steady and extended TeV source TeV J2032+4130 , which lies in the same direction as the binary system , and its potential association with the pulsar .