M94 - Croc’s Eye Galaxy
M94 is a spiral galaxy located 16 million light-years away in the constellation Canes Venatici. New stars are forming at a high rate within the bright central ring. The cause of this peculiarly shaped star-forming region is likely a pressure wave traveling outward from the galactic center, compressing the gas and dust in the outer regions, which collapses into denser clouds. Inside these dense clouds, gravity pulls the gas and dust together until the temperature and pressure are high enough for stars to be born. M94 was initially believed to be roughly 30,000 light-years in diameter, until two faint spiral arms were recently discovered outside of its core region that extend far out into space. This discovery has effectively tripled the galaxy’s known diameter.
May 4, 2025
It’s springtime, so clouds, breezes, and intermittent precipitation persist! It’s been about a month since my last image, but there were a couple clear nights for me to capture some data. This image actually is the result of a few spare hours of data from back in April, and a reasonably clear (but windy!) night a few nights ago. Guiding wasn’t great on either night because of the wind, and I tossed out about 2 hours of subs due to clouds. Undeterred, I went ahead and processed the data anyway. I was pleased that I was able to capture a hint of the faint outer ring of the galaxy. Darker skies, more integration time, and a faster scope would certainly bring out more details, but it’s a big universe out there, so it was time to wrap this target up for the season. I’m still pleased with the Triband filter on starburst galaxies. I’m able to capture and enhance some of the nebulosity without needing to shoot dual narrowband in addition to luminance, though I will be experimenting with this in the future whenever I can get a solid strong of clear nights!
Technical Details
Imaging Telescope: Celestron C9.25 XLT
Imaging Camera: ZWO ASI533MC Pro
Mount: Sky-Watcher EQ6-R Pro
Filter: Antlia Tri-band RGB Ultra Filter - 2” Mounted
Accessories: ZWO ASIAIR Plus, ZWO EAF, Antlia OAG with Filter Drawer, Starizona SCT Corrector 0.63x IV, Baader Diamond Steeltrack Focuser
Software: Siril, PixInsight, BlurXterminator, NoiseXterminator, SetiAstro Statistical Stretch, SetiAstro Star Stretch
Guiding Camera: ZWO ASI174MM
Imaging Dates: April 14 and May 2, 2025
Frames (gain 101.0) f/4.9 -10c: 130x180” (6.5h)
Integration Time: 6.5h
Darks/Flats/Dark Flats: 30/30/30
Bortle Dark-Sky Scale: 6.00