About the LASCO Blink Tool

Comparing two astronomical images taken at different times is a well known method of finding differences. The dwarf planet Pluto was discovered by this method. "Blinking" images is used to find objects moving in the sky by aligning two images so that the background starfield is held stationary and looking for differences. This tool takes two LASCO images and "blinks" them. For C2 it chooses images roughly 3 hours apart. For C3 it chooses the first and last image of the day. If you point to a star with your mouse, it will not move (much). Due to optical distortion and the fact the browser can shift the images by only an integer number of pixels the shift is only approximate.

Planets, asteroids and comets are seen as moving objects against the background starfield. Use an almanac or starchart to identify which object you are seeing. You might also look for stars that change brightness. It could be a nova or supernova!

The images have lots of cosmic ray hits so there are lots of spurious bright points making them more difficult to blink, so if you find an object in the field confirm it using the movie tool.

To Do

The tool currently will not wrap around to a past month when choosing which day to examine. This is a problem at the beginning of a month.