Here's why:

* Spectral Class: The Sun is classified as a G-type star based on its spectral characteristics, particularly the presence of certain absorption lines in its spectrum.

* Luminosity: G-type stars fall within a specific range of luminosity, and the Sun fits comfortably within that range.

* Temperature: G-type stars have surface temperatures around 5,200 to 6,000 degrees Celsius, which is very close to the Sun's temperature of about 5,500 degrees Celsius.

* Size: Yellow dwarfs are considered "main sequence" stars, meaning they are in the stable phase of their life cycle, fusing hydrogen into helium in their core. The Sun's size and mass fall within the typical range for yellow dwarfs.

While the term "yellow dwarf" is not a formal astronomical classification, it's a common way to refer to stars like our Sun.