55 Million Solar Masses

My latest image from Australia is Centaurus A (NGC5128), a large, unusual galaxy.  The photo looks like a thick dust lane with a very bright star behind it, but all that glowing in the center is actually from the core of the galaxy, which includes a supermassive black hole, estimated to be 55 million times the mass of our Sun (which is itself far beyond the size of objects in normal human experience).

If my camera could pick up x-ray and/or radio signals we would see enormous jets radiating from the center, perpendicular to the disk.  The inner portions of these jets are moving at roughly half the speed of light.  The x-ray portion extends for thousands of light-years, and associated radio jets are over a million light-years long.

The galaxy appears to have undergone a merger with another galaxy, and perhaps because of the chaos that caused, the exact galaxy type for Centaurus A is uncertain, as is its distance (estimated at somewhere between 10 and 16 million light-years).

Below is a tight crop from the above image:

At this size you can see the blue regions (especially at the upper right edge of the galaxy) that are typical of hot, young stars, plus the bright red spots throughout the galaxy that are hydrogen emission regions.  The exposure consists of 3 hours each of red, green, and blue; 4.5 hours of luminance; and 4 hours of Hydrogen-alpha.  I first created a color image using just the RGB data, then added the H-alpha data to the red channel to bring out the hydrogen regions.  H-alpha was also combined with the luminance data, which was then applied over the RGB color image.

Hopefully, we’ll have one more image from Australia soon, but it’s Winter there now, so data collection has been a bit slower due to the weather.  Meanwhile, I’m trying to get out as often as possible to shoot more northern hemisphere objects – when I can get away from customer orders!


About Greg Marshall

I am a retired electronics engineer and after a few months of enjoying my leisure I began to miss doing product development. My astronomy hobby always needed new solutions to unique problems, so I decided that whenever I came up with a good solution I would try to make it available to others.

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