What will happen to the shape of a galaxy when a super massive black hole lying in its center dies(evaporates out)? What's at the Center of the Milky Way?
 In this article it is said that a supermassive black hole lies in the center of milky way galaxy.


  At its center, surrounded by 200-400 billion stars and undetectable to the human eye and by direct measurements, lies a supermassive black hole called Sagittarius A*, or Sgr A* for short.
  The Milky Way has the shape of a spiral and rotates around its center, with long curling arms surrounding a slightly bulging disk. It's on one of these arms close to the center that the sun and Earth are located. Scientists estimate that the galactic center and Sgr A* are around 25,000 to 28,000 light-years away from us. The entire galaxy is around 100,000 light-years across.


We revolve around the center every 250 million years.Presumbably we rotate beacuse of the BH.

When the black hole dies in our galaxy will we be thrown out of the revolving orbit?

The shape of the galaxy is expected to change right?It will be some irregular shape not spherical?
Presumbably we rotate beacuse of the BH.


No. The galaxy is being held in one piece due to its own total gravity. The black hole is only a small fraction of that. Basically, the BH doesn't matter.


  When the black hole dies in our galaxy


The BH will probably be the last thing left of our galaxy at the end. And even then it will take some incredibly long time for it to evaporate. BH evaporation for very large BHs is basically the slowest process you could imagine.


  It will be some irregular shape not spherical?


The galaxy is not spherical. Its shape is rather more like a round disk (with some irregularities and some features like arms, etc).