Abell 1656 Spring 2023 – time for project nightflight to set out on a new journey and start another project. So, what's in the sky to explore? Abell 1656, the Coma Galaxy Cluster is a target worthy of our attention. The Coma Galaxy Cluster is no object for novice stargazers or beginner amateur astronomers. It might rather pique the interest of practiced deep-sky aficionados with the patience and the equipment to observe or image hidden jewels of the night sky. For them, Abell 1656 will reveal a wealth of galaxies that are unimaginably remote.
Abell 1656 Coma Galaxy Cluster by project nightflight
In our image we were able to reach galaxies down to the 18th magnitude. The field of view shown is 1.6 degrees wide, which corresponds to about three times the size of the full moon. We invested a mere 1.7 hours of exposure with an astrograph and discarded the red and blue channels of the image. We only processed the green channel, because this best corresponds to the sensitivity of the human eye. The shot was made with a 66/400mm apochromatic refractor and a highly sensitive astronomical camera, cooled down to -5 degrees Celsius to minimize thermal noise. At first glance, the cluster appears to be no cluster at all. The dominant objects in the field of view are two elliptical monster galaxies, NGC 4889 and NGC 4874. Their diameters of about 300,000 ly makes them both considerably larger than the Milky Way, which is roughly 120,000 light-years across. Seen from the Coma Galaxy Cluster, our own galaxy would look like one of the smaller specks in this image. And, of these smaller specks, there are many. The central section of our image roughly equals the space occupied by our own Milky Way galaxy, M33, and the Andromeda Galaxy, the Local Group. However, in comparison, the galaxy density is extremely high in the Coma Galaxy Cluster. Hundreds, even thousands of galaxies are packed tightly together in this cluster. As a side note it is perhaps interesting to mention that the cluster is part of the Northern Great Wall. This is an immense galaxy filament, that is one of the largest known superstructures in the observable universe. With all the astronomical and imaging details being delivered, let's return to the magic of the Coma Galaxy Cluster. Interestingly, its exact distance from Earth is unknown to this day. At present, different methods of measurement deliver distances between 280 and 360 million light-years. So, it is more or less safe to say that the Coma Galaxy Cluster is around 330 million light-years away from our own position in space. This means that the photons captured by our imaging sensor have travelled through space for around 330 million years. That long ago, our planet Earth looked vastly different than it does today. The supercontinent Pangea was in the process of formation at this time. It later spanned from the north pole to the south pole, combining all landmasses in a single, enormous continent. Landmasses were covered with endless forests populated with the predecessors of today's conifers. Amphibians were the abundant species of the animal realm. Trilobites were sill very numerous. Insects, millipedes, and scorpions grew to gigantic sizes. This has been contributed to the high oxygen concentration of about 35 % in the Earth’s atmosphere during that period. A minor extinction event some 300 million years ago caused the rainforests of that time to collapse and die. This plant matter later decayed and fossilized, which later formed extensive coal deposits. A whole geological period, the Carboniferous was named after this, from the Latin word carbon, which means coal. Given the time that has elapsed since then, it makes you wonder how the Coma Galaxy Cluster actually looks like at present. We only get the ancient light though. If you want to observe it through a telescope, you should use an aperture of at least 100 mm, or 4 inches. At higher magnification, this will reveal the two main galaxies as faint clouds among a small group of stars. The smaller galaxies most likely will not be visible in a telescope. Only long-exposure images will reveal their presence in stunningly large numbers.
Back to PROJECTS
GALLERY GALLERY
PROJECTS PROJECTS
TOOLS TOOLS