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Instructions for Making a
Color Image of SN 1987A

Select where to point the Hubble Space Telescope and its Wide Field/Planetary Camera (WFPC2) in order to make a mosaic.

to the public data archive
Using a blue filter (B) to select only a blue light from the electromagnetic spectrum then expose the WFPC2 detector. Point the telescope again and repeat. Process these data and mosaic them into one black and white image (85 Kb file).

(Why does the WFPC2 have an unusual chevron shape?)

Repeat using a visual filter (V).
And then repeat using a red filter (R).

B filter
one of 85 Kb of images
V filter
one of 85 Kb of images
R filter
one of 85 Kb of images



(The color in the background of these icons gives the range of color transmitted by each filter.)






Check the progress. Assign the B filter the color blue, the V filter the color green and the R filter the color red; this is chromatic ordering Combine these 3 different images to create a 3 color image highlighting the color of the stars.

Repeat above observations and processing using a filter which transmits only the green light of hot oxygen gas ([O III]).

[O III] filter
one of 85 Kb of images
H II filter
one of 85 Kb of images


Repeat using a filter which transmits only the red light of hot hydrogen gas (H II; also called H alpha).

Add the [O III] filter image to the green image.

Add the H II filter image to the red image.

 


122 Kb jpeg of the HST mosaic

Combine these blue, green, and red images to create a 3 color image. Adjust the brightness to show both the stars and the hot gas of the nebula where SN 1987A is located.

Finish off by cropping to show the supernova in slightly more detail.


For a hardcopy version, copy and print according to instructions at our image information pages.