A shooting star is a single candlestick with a small real body near the bottom of its range and a long upper wick at least roughly twice the body, appearing after an uptrend. Price spiked higher during the period and was sold back down to close near the open, leaving a long upper shadow that reads as rejection of higher prices.
It is the bearish counterpart of the hammer: the same geometry, flipped, at the top of a move rather than the bottom. The long upper wick is interpreted as buyers running out of fuel and sellers stepping in, making it a candidate reversal signal at resistance or the top of an extended rally.
Like all single-candle patterns it is low-information on its own and conventionally requires confirmation — a lower close on the following candle, or coincidence with a known level. An identically shaped candle after a downtrend is an inverted hammer and carries a different, potentially bullish, reading, so location is decisive and must be part of any tested rule.