Runaway stars and black holes

Astronomers try to find out why runaway stars leave their birth cluster in a galaxy. Mid-size black holes may be responsible. (Image: FAU/Andreas Irrgang)

FAU scientists discover a runaway star and suspect it originates from a mid-size black hole

Led by astronomers from FAU, an international consortium has recently discovered a new high-velocity star (HVS). These are stars which move at great speed through the Milky Way, sometimes travelling so fast that they may eventually leave our galaxy. Until now, scientists have not yet been entirely sure where these runaway stars find the enormous impulse they need to be able to accelerate to such high speeds. Together with their colleagues, Dr. Andreas Irrgang and Prof. Dr. Ulrich Heber from the Dr. Karl Remeis observatory in Bamberg, the Astronomical Institute of FAU, have collected data which could give new insights into the origin of HVS using one of the largest telescopes in the world, the Keck Observatory in Hawaii.

Using the data, the researchers traced the trajectory of a newly discovered runaway star and discovered that the standard ejection mechanisms could not apply to this star. The researchers were able to rule out the standard scenario, in other words interaction with the supermassive black hole at the centre of our universe. Instead, they suggest that an intermediate-mass black hole may be responsible. Black holes such as this have not yet been found. Based on the traced trajectory of the new HVS, however, astronomers now have an idea where they could look for possible mid-size black holes.

Dr. Karl Remeis Observatory

The Dr. Karl Remeis Observatory is the Astronomical Institute of FAU. (Image: FAU/Boris Mijat)

Further information

Dr. Andreas Irrgang
Phone: + 49 951 9522216


Addition information