A Bent Galaxy. NGC 2146 is about 80,000 light-years in diameter and appears nearly edge-on to us and bent from our point of view. Imagine a round dinner plate slightly bent and then angled so we see only the edge of the plate and not its face. It is no illusion that it appears bent, as it has been extremely disrupted by either merging with another galaxy or the passing of a nearby galaxy NGC 2146A, or both! Note that each galaxy contains 100-200 billion stars, however if they had collided directly head on, statistically they would have passed through each other without ever a star or planet colliding. The most noticeable feature of NGC 2146, is its intensely dusty lanes in the spiral arm closest to us, obscuring much of the starlight of the galaxy core. Visible also are many disturbances in the shapes of small arms and loops along the outer edges of NGC 2146. Each of these arms or loops contains 10s of millions of stars like our sun, each with, on average, a few planets, perhaps tens of moons, and likely tens of thousands to millions of asteroids and comets!

Interacting Galaxy. Imagine a billiard table with zero resistance where a billiard ball moves around, bouncing off the table sides forever, without slowing down. Then imagine each billiard ball is swarm of billions of stars gravitationally bound. As these balls of stars move around the frictionless surface they inevitably come close to, or even collide, with another ball of stars. These close encounters and collisions are how galaxies interact with and disturb each other, occasionally merging with one another to form even more massive galaxies. Most galaxies seem to be the more boring elliptical type without arms or spiral structure. The spiral arms form when galactic density waves occur to align the galaxy into arms. One contributor to the density waves affect may be when galaxies interact with each other.

Starburst Galaxy. As galaxies interact, a larger galaxy often cannibalizes a smaller galaxy by merging with it and taking all of its stars. This may have indeed happened here with a galaxy that no longer is visible but has been absorbed. However, the galaxy NGC 2146A may also have been involved somehow, but was clearly not absorbed. It instead moved on past, perhaps to return in orbit at a distant date, but more likely to move onward toward its next galactic encounter, billions of years in the future. The interaction with NGC 2146A, nearly a billion years ago, however, may have caused additional density waves to ripple through NGC 2146. These ripples in turn push gas and dust together causing the rate of star formation to increase substantially. A galaxy with such a high rate of star formation is called a starburst galaxy. If observed over millions of years, a timelapse video of say one frame per 100,000 years would show stars born rapidly and seeming to appear like fireflies at a much faster rate than normal galaxies.

Discovery:In 1876, Friedrich Winnecke discovered NGC 2146 likely while searching for comets. Winnecke was most famous for creating a list of double stars sometimes designated as Winnecke # or WNC #.

Annotations. The above image shows annotations when hovering over the image. Starting with the lower left and progressing clockwise, the first inset is PGC 2776169 which may be a double galaxy 100s of millions of lightyears way. Next are displaced stars showing the small arms and loops of 100s of millions of stars displaced by the previous merger or interaction. Note the G5 yellow star in this image. This is of similar size, mass, and color as our own star the sun. At visual magnitude 8.31 it is near 10 times fainter than the faintest star visible with the average human eye. PGC 142974 may be a close companion galaxy to NGC 2146. PGC 2776482 and 2775989 are likely very distant galaxies far beyond the 70 million light-years of NGC 2146. Note the galactic nucleus enlarged inset shows more details of the disturbed and bent spiral arm closest to us.

The first image below, shows the same field as above but with the foreground stars removed. Hovering over the image brings them all back. In the second image below, the image has been cropped, rotated slightly, and zoomed to show more detail of the galaxy as if it were horizontal to better see the bent shape