Primärstjärnan HD 34557 A är en vit till blå stjärna i huvudserien av spektralklass A3 V, som har snabb rotation med en projicerad rotationshastighet av 217 km/s. Den har en radie som är ca 1,6 solradier och har ca 40 gånger solens utstrålning av energi från dess fotosfär vid en effektiv temperatur av ca 8300 K.
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