although its also a star, our sun doesnt have a generally accepted and unique proper name. Its just the sun.
You sometimes hear people use the name Sol for our sun. Sol is the Roman equivalent of the Greek sun god Helios. And maybe in earlier times people did actually use these names. According to straightdope.com, the first cited use of Sol as a proper name for the sun is the 1450 Ashmole Manuscript Treatise on Astrology, which stated:
Sol is hot & dry but not as mars is.
So much for ancient knowledge.
And meanwhile neither Sol nor Helios is an official name for the sun, according to the International Astronomical Union (IAU), the international body of astronomers which since 1922 has charged itself with the responsibility for naming all things celestial. By the way, the IAU is virtually alone in the world in suggesting we all use Sun and Moon, rather than the lower-case sun and moon. Most astronomers do capitalize these words (frequently along with other non-standard capitalizations such as Galaxy, Solar System and Universe), but most media organizations (which tend to use media stylebooks such as the AP Stylebook) dont.
So the sun doesnt have its own name. But it does have a symbol thats exclusively its own. The suns symbol is a circle with a dot in the center used in mathematical formulas.
In being nameless, our sun has company. There are several thousand stars visible to the eye, and only a few hundred of them have actual names, as opposed to designations. Astronomers use the Greek alphabet to order visible stars in each constellation, according to their brightness. To identify stars invisible to the eye, astronomers turn to star catalogs, which assign a number to each star according to its position in the sky.
hope this clears it up
Ron