Gaze at a Nearby Actively Feeding Supermassive Black Hole

By Nancy Atkinson - May 2, 2023 at 8:59 PM UTC | Black Holes
hubble_ngc4395_centerright_v5_flat_final_2.jpg

Astronomers recently shared a new image captured by the Hubble Space Telescope of the galaxy NGC 4395. This relatively diffuse and dim dwarf galaxy is located just 14 million light-years from Earth.

NGC 4395 has several oddities, and this new image zooms in on the galaxy's central region to highlight just one of those quirks. NGC 4395 is different from other dwarf galaxies because it contains an actively feeding supermassive black hole at its center.

But this black hole is considered one of the lowest mass supermassive holes ever detected, an oxymoron if there ever was one.

The black hole has "merely" 10,000 times the mass of the Sun, which would make it as much as 100 times smaller than others of its kind. The black hole is only detectable because of the radiation blasting out of the galaxy's center, this bright region in the lower left of this image.

NGC 4395 wears several different hats. It is a dwarf galaxy because of its small size. It is considered a spiral galaxy because of its diffuse but definite spiral arms. However, it's also considered a Seyfert galaxy because it contains an active galactic nuclei (AGN), a small region at its center that is brighter than can be explained by the stellar population alone.

But again, this AGN -- powered by the supermassive black hole -- is one of the dimmest AGNs out there.. It's classified as a Seyfert galaxy and not a full-blown quasar because the amount of radiation from the black hole doesn't overwhelm the rest of the galaxy.

NGC 4395 is also unique among Seyfert galaxies due to its lack of galactic bulge, the tightly packed group of stars often found at the center of a galaxy. Astronomers say it could be that the black hole "ate" most of the stars in the bulge, and doesn't have much more food within reach. That would keep the black hole from growing.

Here's another Hubble image of NCG 4395 that zooms into one of the galaxy's diffuse spiral arms:

Source: NASA

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com