The Morning Star [1] is a pattern seen in a candlestick chart, a popular type of a chart used by technical analysts to anticipate or predict price action of a security, derivative, or currency over a short period of time.
[2] When found in a downtrend, this pattern can be an indication that a reversal in the price trend is going to take place.
What the pattern represents from a supply and demand point of view is a lot of selling in the period of the first black candle.
Then, a period of lower trading with a reduced range, which indicates indecision in the market, forms the second candle.
As the Morning Star is a three-candle pattern, traders often don't wait for confirmation from a fourth candle before they buy the stock.