It is difficult to determine which twinkling star you are referring to tonight, as there are numerous stars visible in the night sky. There may be several bright stars or planets that stand out from the rest. To identify a particular star or planet, you can use a stargazing app or a physical star chart to match the star's position and brightness to the corresponding celestial body. Some notable bright stars that you might see in the sky include Sirius, Vega, Arcturus, and the North Star (Polaris).