Like a glowing stone thrown into a lake at night: the James Webb space telescope took a new image of the star system WR 140, in which you can see beautiful ripples from the star spreading through space.
WR 140 is a Wolf-view type star. Wolf-ray stars are extremely hot massive stars that emit an extremely strong solar wind – that is, they lose material to space at a rapid rate. WR 140, about 5,600 light-years away in the Cygnus constellation, is 20 times more massive than our Sun and is at the end of its life.
But WR 140 is not alone: it is part of a binary, or double, system of stars. Its companion is an even more massive star, with a mass of 50 suns, still melting hydrogen at its core. It so happened that the two stars emit a lot of material into space, at speeds of about 3,000 kilometers per second.
The interesting thing is that the two orbit each other in a very eccentric orbit: instead of two perfect circles around a common center of mass, they move in oval orbits – and at their closest point to each other, the stars come almost to the distance of the Earth from the Sun. At this point, the solar winds of the two hot stars collide.
Animation showing the interaction between the stars. Credit: NASA, ESA, Joseph Olmsted/STScI
The solar wind from the young and massive star blows and accelerates the solar wind of WR 140 – mainly carbon particles. The result looks like tree rings: since the two stars complete the cycle every 7.9 years, every 7.9 years a new ring of hot dust is blown into space. And because James Webb takes pictures in the infrared, the new space telescope is the ideal instrument for studying the heat signature of these rings. In the picture we see about 20 such rings, which means about 160 years of rings.
Many surfers wondered on Twitter about the blue rays emanating from the star. These are lines of diffraction, or diffraction, created by the impact of the waves from the bone in Webb’s lens – similar to what happens when we photograph a street lamp at night. In contrast, the red rings in the image are completely real: they are there in space, expanding and cooling around WR 140.