Hubble's Variable Nebula

A shadow that first appeared on JD 2,451,142 moved northward across the western half of the nebula during the following two months. Frames 142 and 160 below point to the area to watch in the animation.

111	142	150	160	168	171
174	188	204

A simple calculation of the northward movement of the shadow between JD 142 and 160 yields a proper motion in that direction of about 1.3±0.2 times the speed of light. A review of the subtracted animations below shows that the shadow sweeps out an arc of increasing radius that moves eastward as well as northward.
 

Changes from JD 111 See complete page of this animation

Changes for successive intervals See complete page of this animation

As this shadow moves across the western half of the nebula, another shadow is moving in tandem in the south-western region of the nebula. In the left-hand animation above it looks, at first, as though the eastern and western shadows are in fact one shadow that has been cut in two by a bright section of the nebula. However, the right-hand animation above shows successive changes in brightness that suggest that two distinct shadows are crossing the face of the nebula at the same time. In either case, the synchronized behaviour of two shadows or two parts of the same shadow suggests that they are caused by the same source.
 
 

Last modified April 16, 1999