40_Arietis
40 Arietis
Binary star in the constellation Aries
40 Arietis is a probable binary star[3] system in the northern constellation of Aries. 40 Arietis is the Flamsteed designation. Their combined apparent magnitude is 5.82,[2] putting the system near the limit of naked eye visibility. Based upon an annual parallax shift of just 7.33 mas,[1] it is 445 light-years (136 parsecs) away from the Sun. At that distance, its brightness is diminished by 0.21 in magnitude from extinction caused by interstellar gas and dust.[9]
This is a suspected spectroscopic binary with an angular separation of 0.2″ between the two components.[3] The visible component is an evolved giant star with a stellar classification of K1 III.[3] It is a suspected variable star of unknown type,[4] and is around 2.6 billion years old with 1.6 times the mass of the Sun.[7] With the supply of hydrogen at its core exhausted, the star has expanded to 20 times the Sun's radius.[1] It is radiating 128 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,473 K.[7]