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Crab Sans Pulsar | by geckzilla
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Crab Sans Pulsar

A pretty cool public lecture from STScI's Frank Summers is over on Youtube. Explains all these weird shapes far better than I can:


The famous Crab Nebula, a supernova remnant that contains a pulsar with a bright wind nebula intermixed among remnant filaments. Here, I've removed the wind nebula completely, along with the stars and the pulsar itself, leaving only the strange tendrils of leftover from when the star exploded many hundreds of years ago. Apparently the pulsar, not the initial supernova explosion, is responsible for the much of the intricate shaping of the filaments.


Oddly enough the nebula does look a bit fake to me with all the stars removed. Some of the fakeness is also due to the way I covered the awkward edges where the data ended due to the footprint of the WFPC2 detector. Hopefully it doesn't look too bad, though.


Speaking of WFPC2, can you believe Hubble still hasn't looked at this nebula in color since the observations comprising this mosaic were made around 20 years ago? The center has been looked at it relatively recently in polarized light, a mediumband and wideband green filter, and once in near-infrared but never again in enough filters to produce a color image of the whole nebula. You might think that the Crab Nebula is very popular and looked at quite frequently, but that's not the case.


I do think this version shows off the three emission lines better than I've done previously. Blueish hues denote doubly ionized oxygen, reddish colors are singly ionized silicon, and the yellowish areas are where neutral oxygen is present. Some older versions I made can be seen here and here.


Data from the following proposal were used to create this image:

An Emission Line Survey of the Crab Nebula


F547M filter was used for subtraction. Subtraction function was not linear or the same for each channel.


Orange: WFPC2 F673N [S II] - F547M

Green: WFPC2 F631N [O I] - F547M

Cyan: WFPC2 F502N [O III] - F547M


North is up.

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Uploaded on February 1, 2020