Thus, in fact, we are already entering a collision with the neighboring Andromeda galaxy. There is almost no free space left between galaxies.

How was it possible to clarify the size of our galaxy?

More than 200 stars of variable RR Lyra type have been detected along the edges of the borders to clarify the outer boundaries of the Milky Way. Due to their properties, such variable stars make it possible to accurately determine the distances to them. In fact, these are local signs, the characteristics of which are very similar and make it possible to accurately estimate the range. That’s exactly what a group of astronomers from the University of California at Santa Cruz did in the new study.

According to calculations, the distance from the center of the galaxy to its edge is one million light years. Because it is a highly diluted gas, we cannot accurately measure the outer limits of the gas cloud around our galaxy – the so-called halo – from the inside. Therefore, it remained to rely on theoretical calculations based on indirect measurements.

In the new study, scientists used the distance to 208 open variable stars at the edge of our galaxy for this measurement. One such star, for example, was midway between the Milky Way and Andromeda. we are approaching a collision.

This work redefines what the outer boundary of our galaxy is. Our galaxy and Andromeda are so large that there is almost no space between them.
– pointed out the authors of the study.

According to the measurement data, the outer boundary of the Milky Way 40 thousand light years away, more than predicted by theoretical calculations. Scientists backed up the theory with observations that would give astronomers another tool to accurately assess astronomical events in the universe, and there are never too many tools.