Behold the Tadpoles!

This is the nebula IC 410, a tiny little corner of the hexagonal constellation Auriga the charioteer which passes almost directly overhead these frigid nights in the northern hemisphere winter. This image took a lot of work: about a month of taking pictures in between clouds and snow and political violence and tech troubles, then many many hours of processing.

Like so many winter astro-images this is a star nursery in a spiral arm of our own Milky Way galaxy. It’s a clot of gas and dust which is collapsing on itself under its own weight to coalesce into myriad brand-new stars. Freshly lit nuclear fusion in their cores is blasting UV radiation outward through the cloud, lighting up the neighborhood with fluorescent red and cyan. The glowing stuff is plasma, ions of hydrogen (red) and oxygen (cyan) emitting colored light because they are superheated and buzzing with electrical charge.

The “tadpoles” (sperm?) appear to be swimming toward the upper left but are actually more like the wake of turbulent water downstream of a rock in a fast-moving stream that’s moving toward the lower right. Each tadpole is about 10 light years long and about a light year across.

The star-blasted plasma and UV radiation produced by the infant stars (just 4 million years old) is streaming outward, but little clots of dirt (yes, dirt!) are in the way. The plasma piles up against the dirt and gets compressed to the point that the hydrogen (red) and oxygen (cyan) glow even brighter on the upstream side of the clods, then flows around to recombine in turbulent tendrils on the downstream side.

Inside the sperm heads the solid dust (microscopic grains of silicate mineral and carbonaceous soot) shade the environment from the extreme radiation all around, letting the gas cool by infrared emission to the point that yet more new stars can form.

Like the famous “pillars of creation” Hubble image this is a glimpse of the creative destruction of galactic recycling that brings forth new worlds from the ruins of the old, again and again. And like them the tadpoles are evanescent. They are being eroded and consumed by the fierce winds of change that brought them about in the first place. The tadpoles will be gone in the blink of a cosmic eye (less than a million years).

Here on Earth almost everything is either condensed matter (people, plants, animals, rocks, soil, oceans, microbes) or gas (the air we breathe). It’s nearly all electrically neutral, with positive and negative charges perfectly balanced. The rare occurrence of net charge like lightning bolts or the winter spark of your carpet-charged finger on a light switch is a novelty.

But most of the ordinary matter in the universe is plasma, meaning that the positively-charged atomic nuclei (protons and neutrons) and the negatively-charged electrons that we’re accustomed to be bound together have been blasted apart from one another. Plasma is a “gas” made of ions and electrons rather than atoms and molecules.

Like solids, liquids, and gases plasma is a “state of matter.” In a solid the atoms are locked together into a fixed lattice of vibrating atoms kept in place by chemical bonds. Add enough energy in the form of heat or radiation and the lattice breaks in the process we prosaically call “melting.” The molecules can then flow freely but are still coherent as a liquid. Add more energy and the coherent liquid is blasted apart into its free-flying atoms or molecules in the process we call “boiling.”

Beyond these familiar “three states” of matter is plasma. When a gas is subjected to yet more radiation or heat it can go beyond the gas phase when the energy is sufficient to break the chemical bonds and then strip the electrons off the atoms to leave a buzzing soup of bare and unbound charged particles. The positives and negatives attract one another, but the energy of their collisions is too great to allow them to stick.

Plasma glows. Electrons are captured by positively-charged nuclei and emit a photon (red for hydrogen, cyan for oxygen). In the next moment they newly-bound atom is blasted apart again by ionizing radiation.

In the superheated plasma state gravity isn’t strong enough to hold the gas together and collapse it into stars and worlds.

But the dust – oh yes! – the dust! The black tendrils in the middle of this image aren’t void spaces lacking stars and gas and glowing plasma. Rather they are the silhouettes of minerals and organic soot backlit Without the shading by the dusty remnants of old dead stars new stars couldn’t be born.

It’s only in the cool dark shade of dead-star-dust that the plasma can cool enough for gravity to take over, squeezing the gas into collapsing spheres that eventually light up as protostars. Intense radiation driven by fusion in the protostars then carves out a transparent hole in the nebula and whatever leftover dust is gravitationally bound to the new star can coalesce to produce planets, plants, and people.

This image is a combination of 150 black-and-white pictures: 77 x 2-minute exposures taken through red, green, and blue filters plus 73 x 10-minute exposures taken through special narrowband filters which ONLY allow the special colors emitted by oxygen and hydrogen ions to come through. I shot these pics at a focal length of 1494 mm (about 5 feet) over the past three weeks. Every image gets “dark subtracted” and “flat-field corrected” before being aligned and stacked in software. Each pixel has a red, green, and blue value that’s the average of the 150 values at that position in hundreds of component shots. It’s a lot of work!

IC 410 is about 12,400 light years away, looking along a spiral arm toward the outer rim of our galaxy. We look back 12,400 years as we see it, to the time when early people were just beginning to domesticate wild plants and animals as they emerged from the last Ice Age.

DETAILS:

ASI1600 on C8 EdgeHD f/7 (FL=1495 mm) with reducer and Moonlite CHL focuser & OAG on a 10Micron 1000HPS mount from Bortle 6 suburbia.

R 27x120s G 26x120s B 27x120s Ha 44x600s O3 29x600s

Captured in KStars/Ekos under ubuntu 20.04. Processed in PixInsight on a Mac mini



Calibrated w 30 darks, 30 flats, 30 flat-darks for each light frame

LINEAR: Crop, DBE, MureDenoise, Deconvolution, RGB Photometric Color Calibration and then NBRGB combination

StarNet++ followed by separate processing of stars (color saturation) and nebula (strong stretch)

Brightened in Mac Photos for web presentation