Supernovae occur roughly once a century in a typical spiral galaxy. However, precise observations of the centre of the Milky Way have shown a ribbon of high mass stars, all forming at once. This mean that one day, in about 100 million years, these stars will all explode about at the same time, creating a beautiful celestial phenomenon known as starburst. (Similar in mechanics to starburst galaxies, which are undergoing rapid periods of star formation)
It is typically believed that these periods occur when two galaxies gravitationally interact with one another, before ultimately merging — something our galaxy will experience in about 5 billion years when our closest celestial neighbor, the Andromeda galaxy, collides with our own. After which, the shockwave sent through the new, larger galaxy, will cause the massive clouds to collapse, forming hundreds of thousands of high mass, blue-white stars, ultimately sparking a new era in the evolutionary process of the Milky galaxy. The last starburst period our galaxy experienced took place about 4 to 6 million years ago, when the Quintuplet Cluster, the Central Cluster and at least one more open cluster formed, likely after perturbations occurred between stars and the super-massive black hole that lies at our galaxy’s center.
An example of this is M82 (also known as the Cigar Galaxy), in the constellation of Ursa Major.