It’s galaxy season! In April and May, the night-side of our Earth looks out of starry plane of our own galaxy and into the vast blackness of intergalactic space. Here, in constellations like Virgo, Ursa Major, and Coma Berenices, there are thousands of galaxies assembled by gravity into clusters and superclusters. Sweep this region with a mid-sized telescope, and you have no problem finding galaxies. The problem is figuring out which is which.
With a small telescope of 3″-4″ aperture, if you’re persistent, you might see a hundred galaxies, maybe half of which present intriguing views. Perhaps fewer in light-polluted skies. In dark skies, with the help of CCD’s and image processing know-how, thousands of galaxies are within reach of skilled observers. Many connoisseurs pick through maps and atlases of faint galaxies looking for the most photogenic targets. One such master observer is Terry Hancock, whose work has been featured here before. Let’s take a peek at his latest work, an image of NGC 4395, a small, dim galaxy with a surprise at its center…
*** Highly Recommended ***
A concise guide to observing the universe beyond our solar system. Secrets of the Deep Sky includes tips on equipment selection and observing techniques, along with a tour of dozens of lovely sights in the north and south hemispheres. Click here to learn more…
* * * * * * * * * *
While obviously a beautiful object, NGC 4395 also holds the attention of research astronomers. This peaceful-looking object seems all disk and no core, but there’s some energetic business taking place in the center of this small, irregular spiral galaxy. Astronomers have found hot and energetic gas at the center of the galaxy, and they’ve determined the galaxy contains a central small supermassive black hole. That’s a crazy definition, I suppose. But most galaxies have supermassive black holes at the center of some 1-2 million or more solar masses. In NGC 4395, the black hole is just 300,000 solar masses.
Many of the larger Seyfert galaxies have very bright cores, and in images give the appearance of a fried egg. You can learn more about Seyfert galaxies here.
This image of NGC 4395 was taken by Mr. Hancock over 6 nights in April and early May 2013 from Fremont, Michigan with a QHY9M monochrome CCD and an Astronomy Technologies Astro-Tech 12″ f/8 Ritchey-Chrétien astrograph. More about the image here.
NGC 4395 lies about 14 million light years away in the constellation Canes Venatici. Because of its low surface brightness, it’s a difficult object to see visually.