RCW 89: A less-imaged Supernova
OTA: PlaneWave 20" f/6.8
Observatory: iTelescope
Filters: R, G, B, H, O
Image Width: 37 arc-minutes
Processed by Alex Woronow (2023) using PixInsight, Topaz, 3DLut
RCW 89 (aka MSH 15-52) is a supernova remnant of an explosion estimated to have occurred about 1700 years ago. Not that long ago, on the grand scale of things! The cloud's shape does not abide by the spherical-shell geometry that other exploded stars seem to favor—well, maybe a little once you know what to look for. But measurements reported in
https://arxiv.org/pdf/2005.07721.pdf show 5000km/s radial winds, as would be expected from a point explosion.
Data & Processing: The narrowband images had poor tracking with a star-axis ratio of almost 2::1. Nonetheless, the narrowband and broadband images were stacked, generating an RGBHO "true color" image. This involved using a script that extracts the emission lines from the continuum and puts the results into the RGB image's corresponding filters. (I wrote a PI script to extract the emission line from the background called NbAssistant. Be glad to share!)
After BXT, the image was stretched, denoised (NXT), and the stars removed (StarNet2). Topaz Studio2 executed some basic adjustments then 3DLut finished off the process. I reintroduced the stars back in PI using the script AC_Restar (I wrote and will share). It maintains the correct, calibrated star colors through the transfer step, which neither cut/paste nor unscreen/screen does correctly.
Hope you enjoy this rather rarely imaged target.
Alex Woronow
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