Astronomy Without Telescopes

Mariko Kato (Professor, Department of Foreign Languages and Liberal Arts)

Astronomy is the study of celestial objects on a very large scale, such as stars, galaxies, and the universe. It encompasses not only vast spaces but also immense timescales, studying events from the distant past before the solar system or humans existed, and even the beginning of the universe. To study celestial objects, various observational instruments are used, including optical telescopes, radio telescopes, and X-ray telescopes (mounted on artificial satellites). However, there are also research methods that do not use telescopes. This involves recreating celestial objects within a computer.

I study novae. A nova is a phenomenon that occurs when a normal star, like the Sun, and a small, dense star called a white dwarf orbit each other in close proximity. Gas from the normal star falls onto the white dwarf, triggering an explosive phenomenon on its surface and causing it to suddenly brighten. The figure on the left is an artist's conception of the nova U Scorpii, based on my theory. When hydrogen gas explodes on the surface of the star at the center of the gas disk, the gas expands significantly and brightens. Even with a telescope, it is not only impossible to see such fine details, but it is also impossible to resolve the two stars separately. Theorists construct physical theories based on various observational results and perform numerical calculations on computers to get closer to understanding the nature of celestial objects.

When a nova explodes, it scatters carbon and oxygen into space. Certain types of novae eventually undergo a supernova explosion, producing large amounts of iron. Separately, massive stars undergo a supernova explosion at the end of their lives, releasing silicon and nickel. These elements mix with the gas that serves as the material for star formation, and new stars are born. The elements that make up life on Earth were synthesized in this way inside stars long ago. The personal computers in our labs are connected to these distant events in the universe.