No, OGLE-2005-BLG-390L b is not a serial number. OGLE-2005-BLG-390L b is the most Earth-like planet discovered orbiting another star.

OGLE-2005-BLG-390L b is an extrasolar planet orbiting the star OGLE-2005-BLG-390L and is 28000 light years from earth. It is situated in the Sagittarius constellation and is near the center of the Milky Way galaxy.

This is the first extrasolar planet discovered to be similar to Earth.

However, the star OGLE-2005-BLG-390L is a cool brown dwarf which means it doesn’t give off much heat. Also, the planet is 2.5 times farther from the star than Earth is from the sun (380,000,000 km). This means the surface temperature be under -350°F.

It is roughly 5 times more massive than earth, but is prediected to be a rocky planet – unlike most extrasolar planets discovered so far that tend to be gas giants like Jupiter and Saturn.

The discovery was announced on January 25, 2006.