There are more barred spiral galaxies than regular spiral galaxies and elliptical galaxies combined. They make up about 60% of all galaxies. The structure of the visible beam is a result of the aligned orbits of the stars and galactic gas. This creates a dense region as individual stars move in and out of the region over time.
The latest Hubble Space Telescope is a collaborative instrument between NASA, the United States and the European Space Agency. It shows details using data collected from the six different Hubble filters found in a barred spiral galaxy. It is large in size, called NGC 4731, and is located in the constellation Virgo. Located about 43 million light-years from Earth, it reveals bright colors of bobbing gas and dark streaks of dust. The bright pink area is the birthplace of stars. While the most noticeable are the long glowing lines on the spiral arms.
Astronomers revealed that spiral galaxies appear to form concentric bands as they grow. This helps explain the large number of rays we see today in galaxies of the same type. But spiral galaxies can also lose their rays if the mass accreted along the rays becomes unstable.
Image source: ESA/Hubble and NASA, Dr. Thilker