NGC 2997 — A Grand Design Spiral in Antlia’s Southern Sky
NGC 2997 is a grand design spiral galaxy of morphological type SA(s)c, located in the constellation Antlia. Seen almost perfectly face-on, its sweeping spiral arms trace an elegant and highly organized structure, spiraling outward from a compact, luminous nucleus and revealing the underlying gravitational density waves that shape its disk.
At a precisely measured distance of 40.0 million light-years, NGC 2997 spans 8.9 × 6.8 arcminutes, corresponding to a true diameter of approximately 104,000 light-years, placing it among the large spiral galaxies comparable in scale to the Milky Way. With an integrated magnitude of 9.5, it is one of the most structurally detailed nearby spiral galaxies visible from southern latitudes.
Its arms are densely populated with brilliant pink H II regions, vast clouds of ionized hydrogen energized by recently formed massive stars. These regions outline the spiral pattern with exceptional clarity, while complex dust lanes wind inward toward the center, creating layered textures of absorption and illumination. The central bulge glows with the warm light of older stellar populations, contrasting strongly with the cooler blue hues of young stars embedded throughout the arms.
NGC 2997 stands as a textbook example of a grand design spiral galaxy, its symmetry and rich star-forming structure offering a clear window into the physical mechanisms that govern spiral density waves, star formation, and the long-term evolution of galactic disks
Imaged in LRGB and H alpha on the ASA Astrosysteme AZ 1500 at Observatorio El Sauce, Chile.
Image Acquisition and Processing: Mike Selby