The Biggest Light Echo Ever

the biggest light echo's ever

Light echoes from Circinus X-1

The biggest light echo ever experienced – created by X Ray light – have been captured by NASA in some amazing images.


A light echo is a light bouncing off the dust from a stella star. The light from the bursting star is reflected by the dust towards Earth in an indirect path. Because of this path and the time delay that it takes for the light to reach us -which in this case is between 1-3 months – the X Rays arrive in these incredible ring formations.


These particular rings were delivered by a huge flare from a neutron star and give us the opportunity to measures its distance from our planet. The rings appear around a star stystem in the plane of the Milky Way galaxy containing the neutron star. The double star system is called Circinus X-1 and the neutron star is a remnant from a supernova explosion.

Many light years away

Shrouded by thick clouds of dust and gas, the star is difficult to measure the distance to from Earth, but these X Rays provide an opportunity. The echo rings suggest that Circinus X-1 is 30,700 light years from planet Earth. The team of astronomers from University of Wisconsin, USA, who have studied the data, believe the X Rays were released in the fall of 2013.

The different rings and colours are the result of the different light refractions and the researchers believe that they each came from a different dust cloud.

Jet speed like a black hole

Now we have a better distance estimate for Circinus X-1, it suggests that it is much brighter than we thought before. The research team also established that the particles produced by the activity travelled at 99.9% of the speed of light and this is something only normally associated with jets from a black hole.

The following video offers an idea of a light echo captured by Hubble.