Abell 43
Abell 43
Planetary Nebula in Ophiuchus

Click here for uncropped versions:  40%, uncropped (1484x1484) 65%, uncropped (2412x2412) 100%, uncropped (3710x3710)


Abell 43: This is a very small (about 85 arcseconds by 80 arcseconds) and dim (magnitude 14.7) planetary nebula in the constellation Ophiuchus. A "planetary nebula" (so called because the astronomer who first identified them as nebulae noted the color was similar to the then recently-discovered Neptune) is a structure of gas resulting from the death throes of a star about the size of our sun, when it runs out of fusable material; the color is the result of the gas being ionized by the remnant of the star, a white dwarf (ionize oxygen is the dominant emission in this planetary nebulae, giving off the characteristic blue-green color). Due to its roughly spherical shape and extensive web of tendrils weaving through it, it has some resemablance to a ghostly soccer ball, hence its nickname "Galactic Soccer Ball." It is estimated to be approximately 7000 light years from earth, which would give it a diameter of about 2.5 light years.


Technical Information:

(L+OIII)(R+Ha)(G+OIII)(B+OIII): Ha-600, OIII-690, L-255, R-195, G-180, B-180 (Luminance layer was a blend of 17 fifteen-minute, luminance-filtered images and 23 thirty-minute OII_filtered images; Red channel was a blend of 13 fifteen minute red-filtered images and 20 thirty-minute Ha-filtered images; Green channel a blend of 12 fifteen-minute green-filtered images and the same OIII dated blended with the luminance layer, and the blue channes was a blend of 9 20-minute blue-filtered images and the OIII data. All images unbinned.

Equipment: RC Optical Systems 14.5 inch Ritchey-Chretien carbon fiber truss telescope, with ion-milled optics and RCOS field flattener, at about f/9, and an SBIG STX-16803 with internal filter wheel (SBIG filter set), guided by an SBIG AO-X, all riding on a Bisque Paramount ME German Equatorial Mount.

Image Acquisition/Camera Control: Maxim DL, controlled with ACP Expert/Scheduler, working in concert with TheSky X.

Processing: All images calibrated (darks, bias and sky flats), aligned, and combined in Pixinsight. Color combine in Pixinsight. Some finish work (background neutralization, color calibration, gradient removal, deconvolution) done in Pixinsight; some finish work (Neat Image noise reduction, Smart Sharpening, LRGB combination, contrast and saturation adjustment) was done in Photoshop CC.

Location: Data acquired remotely from Sierra Remote Observatories, Auberry, California, USA.

Date: Images taken on many nights in June and July of 2020. Image posted July 29, 2020.

Date: Image scale of full-resolution image: 0.56 arcseconds per pixel.

Seeing: Generally good, with calibrated luminance images varying from 1.6 to 2.1 arcsecond FWHM

CCD Chip temperature: -25C

Copyright 2020 Mark de Regt

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