Astronomy G6001: Radiative Processes

Light Echoes - Oct 4

When a star has a bright outburst, the light may illuminate clouds or sheets of interstellar dust in its vicinity and along the line of sight to us. The arrival of the scattered light is delayed from the arrival of the direct signal, resulting in apparent rings that expand in time. Some of the more spectacular examples are illustrated here.

Star V838 Monocerotis

V838 Monocerotis

Light Echoes from V838 Mon in 2002 from the Hubble Space Telescope, and animation

Supernova 1987A

SN 1987A

Light Echoes from Supernova 1987A from the Anglo-Autralian Telescope

X-ray outburst of Soft Gamma-ray Repeater 1E 1547.0-5408

X-ray Jan 23 Jan. 23

X-ray Jan 24 Jan. 24

X-ray Jan 25 Jan 25

X-ray Jan 25-26 Jan 25-26

Black Hole X-ray Nova V404 Cyg

V404 Cyg

Swift satellite animation of X-ray scattering halo from the outburst of the black hole binary V404 Cyg on June 30 - July 4, 2015

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Updated: September 4, 2017