February 7, 2017

NGC 2371 & 2372, a Planetary Nebula in Gemini (Jan. 2017)


Here is a planetary nebula that sits just south of Castor and Pollux, the two bright stars in the heads of Gemini.  The nebula looks a bit like taffy candy.  The Taffy Nebula?

The data for this image was gathered through Astronomik 6nm-wide narrowband filters focused on the emission lines of Hydrogen alpha (H-α) and OIII.  The H-α filter may also pick up some NII emission at 658.4 nm.  Two hours of data (8x900") were collected through each filter.  The two data sets were combined with a synthetic green channel to create an RGB.  The color of the image matches closely the cyan of the OIII emission, which predominates the data, but the image preserves also the H-α [+NII] emission, and particularly the jets coming from the central star.  I have included the separate monochrome data from the two sets below.  The nebula's central star is about magnitude 14.8.

This image was taken through the CFF 290 Classical Cassegrain at f/7.93, with the SXVF-H9 camera.

Here is a link to a Hubble image of the nebula.

Here is the OIII:

Here is the Hα:

And here is an inverted and stretched OIII version showing the looping of the jets back around to form the taffy wrapper pulls, or, at least, that's what it looks like to me.  An interesting paper discussing the nebula's structure is here: https://arxiv.org/ftp/arxiv/papers/1206/1206.1902.pdf.



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