The impact of Vega on a short call butterfly option strategy is that it can affect the value of the options in the position differently. Vega is a measure of an option's sensitivity to changes in implied volatility. A short call butterfly position generally has a positive Vega, which means that as implied volatility increases, the value of the position will increase. An increase in implied volatility will increase the value of both short call options and long call options, but the short call options will increase more in value than the long call options. This creates a Vega imbalance in the position, with the short options being more sensitive to changes in implied volatility than the long options. Therefore, when implied volatility is high, the short call butterfly will be more profitable. Conversely, when implied volatility is low, the short call butterfly will be less profitable. It's important for investors to be aware of the impact of Vega on a short call butterfly option trading strategy and to adjust their positions accordingly.