Magnitude +11.2 face-on spiral galaxy NGC 6814 lies in the constellation Aquila, 74.4 million light-years from Earth. Click the image for a full-size view. Image credit: ESA/Hubble & NASA. Acknowledgement: Judy Schmidt.Spiral galaxies together with irregular galaxies make up approximately 60 percent of the galaxies in the local Universe. However, despite their prevalence, each spiral galaxy is unique — like snowflakes, no two are alike. This is demonstrated by the striking face-on spiral galaxy NGC 6814, whose luminous nucleus and spectacular sweeping arms, rippled with an intricate pattern of dark dust, are captured in this NASA/ESA Hubble Space Telescope image.
NGC 6814 has an extremely bright nucleus, a telltale sign that the galaxy is a Seyfert galaxy. These galaxies have very active centres that can emit strong bursts of radiation. The luminous heart of NGC 6814 is a highly variable source of X-ray radiation, causing scientists to suspect that it hosts a supermassive black hole with a mass about 18 million times that of the Sun.
As NGC 6814 is a very active galaxy, many regions of ionised gas are studded along its spiral arms. In these large clouds of gas, a burst of star formation has recently taken place, forging the brilliant blue stars that are visible scattered throughout the galaxy.
Spiral galaxies oriented face on to Earth offer spectacular views while giving astronomers a better chance to monitor the frequency of supernova blasts. A prime example is a galaxy known as NGC 5468 where at least five stellar explosions have been spotted.
Seyfert galaxies are unusually luminous, powered by supermassive black holes feeding on galactic dust and debris. It is difficult to peer into the dust-shrouded cores of such galaxies, but the European Southern Observatory, combining radio and optical observations, provides an intriguing glimpse.
Using an orbiting radio-astronomy satellite combined with 15 ground-based radio telescopes, astronomers have made the most-detailed astronomical image yet, revealing new insights about a gorging black hole in a galaxy 900 million light-years away. The image has the resolving power of a telescope about 62,500 miles wide, or almost eight times the diameter of the Earth.
