BD+43° 3654

BD+43° 3654 is a star in the constellation Cygnus.

Features

BD+43° 3654 is a blue supergiant star of spectral type O4If with a mass around 70 times larger than the Sun, likely 850,000 times brighter, and very young, with an age that has been estimated to be around 2 million years.^[1] Its distance to the Solar System has been estimated to be 1.45 kiloparsecs (4,700 light-years) ^[1] and it's moving at high speed through the interstellar medium, creating a shockwave in front of itself.^[1]

Studies of the trajectory and speed of BD+43° 3654 has proven it's a runaway star that was ejected from the nearby, massive stellar association Cygnus OB2, making it one of the most massive runaway stars known in the Milky Way along the also O-type supergiants Lambda Cephei and Zeta Puppis.^[1]

While initially it was suggested a supernova explosion of a former companion star in a binary system would be the cause of the high velocity of BD+43° 3654,^[1] later research has proven that a supernova would not be strong enough and, given this star is younger than other stars in Cygnus OB2, an alternative scenario has been proposed in which BD+43° 3654 would be a massive blue straggler that was born in an encounter between two former double stars in the core of Cygnus OB2. In this setting, two stars of each binary would collide and merge forming a larguer and more massive star (BD+43° 3654), that would be ejected of the stellar association as well as the two other stars, that would end exploding as supernovae leaving behind two pulsars -identified as B2020+28 and B2021+51-, whose dynamics show to have been too expelled from Cygnus OB2.^[3] A derivative consequence of the latter scenario is that the brightest and most massive stars of Cygnus OB2 would be blue stragglers too.

References