Celestial hemisphere:  Northern  ·  Constellation: Pisces (Psc)  ·  Contains:  M 74  ·  NGC 628
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M74, Scott Denning
M74
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M74

Getting plate-solving status, please wait...
M74, Scott Denning
M74
Powered byPixInsight

M74

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Description

M74

Early-Mid December 2020

Kind of crappy ... many nights of integration across a couple of weeks with the Borg 125f8 (FL=1050 mm) on the CEM40 with the ASI1600 guided with the Kowa guider

L 33x180 R 45x180 G 45x180 B 45x180 Ha 8x600 total

Preprocesseed with darks & flats, then heavily selected & weighted

Noise reduceed, deconvolved, stretched, StarNet++ to separate stars from galaxy

lots of attempts to reduce blue bloat and color balance, but pretty unhappy with the result. Lots of purple halos!

A classic “Grand Design” spiral galaxy, M74 floats in the intergalactic darkness far beyond the bright foreground stars of the V-shaped constellation Pisces the fish. Two symmetrical arms studded with new blue stars and fluorescent red gas loop far around its buttery yellow core where stars can’t form. It’s smaller in the sky than the nail on your little finger held at arm’s length, quite close to a star named Kullat Nunu.

Pisces is part of a group of dimly-lit water constellations of late autumn which form a kind of celestial sea: Aquarius the water-bearer, Cetus the whale, Delphinus the dolphin, Pisces Austrinus the southern fish, and Capricornus the “sea goat” (huh?). Ancient Mesopotamians may have associated this dark southern sky with the vast wetlands that stretch downstream from their land between the rivers.

As our end of the sapphire ball leans away from the central fire this time of year so also does our evening view tip down and away from the galactic disk that dominates our summer nights. No more glittering band of Milky Way studded with nebulae and clusters. Rather, beyond the sparse stars of the watery constellations our eyes are drawn out the bottom of the galactic disk and across a gulf of cosmic depth through the intergalactic void.

M74 isn’t part of our Local Group of galaxies. It’s more than a dozen times more distant than our galactic neighbors in Andromeda and Triangulum. It spins about 33 million light years away. We see M74 during Earth’s early Oligocene period, a time of profound transition as the world of mammals matured and the climate cooled. It’s about halfway between our own time and the huge impact that wiped out most species 65 million years ago and cleared the way for the rise of our furry ancestors.

At the time of this image, the collision of India with Asia that raised the Tibetan plateau and crinkled the crust had already been drawing down atmospheric CO2 through chemical weathering for millions of years, and it was starting to get cold. Antarctica and Australia pulled apart around the time we see M74, opening the Drake Passage so that cold water swirled all the way around the new Circumpolar current and isolated Antarctica.

Permanent ice sheets began to grow for the first time in hundreds of millions of years. The middle latitudes dried out and vast grasslands emerged as the forests retreated deep into the tropics. Herds of grazing mammals evolved to eat the grass. The Tethys Sea began to close and the Alps began to rise, hemming in the Mediterranean Sea and giving birth to the European landmass.

This is about 8 hours of exposures collected over a period of about a week from Fort Collins. It’s a stack of 3-minute exposures at a focal length of 1050 mm with a black-and-white camera covered with alternating clear, red, green, and blue filters. All the images are collected on a Raspberry Pi under the scope using a program called KStars. Then I sort through the pile and process them on a mac using a program called PixInsight.

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M74, Scott Denning