A spiral in equilibrium—NGC 5247 traces the ordered flow of stars and gas across a vast stellar disk
NGC 5247 is a grand design spiral galaxy classified as SA(s)c pec, located in the constellation Virgo. Its nearly face-on orientation reveals a remarkably symmetric two-arm spiral pattern, with sweeping arms that emerge cleanly from a compact nucleus and maintain coherence far into the outer disk. The “pec” designation reflects subtle distortions in this symmetry, likely tied to gravitational interaction within its environment.
The galaxy lies at a mean redshift-independent distance of approximately 110 million light-years. It spans an apparent size of about 3.5 arcminutes, corresponding to a physical diameter of roughly 112,000 light-years
The spiral structure shows several noteworthy features beyond its overall symmetry. The arms are lined with well-defined chains of H II regions, forming a discontinuous but clearly organized pattern of star formation rather than a uniform distribution. Along the inner portions of the arms, dust lanes curve inward in a coherent flow pattern, tracing the transport of gas toward the central regions. There is also a subtle bifurcation in sections of the spiral arms, where a single arm briefly splits into parallel strands—an indicator of density wave complexity within the disk
A faint, diffuse outer envelope or halo of starlight surrounds the main spiral pattern, extending beyond the brightest arms and giving the galaxy a soft edge rather than a sharply truncated disk. This outer structure suggests an extended stellar disk that is still dynamically relaxed despite the internal perturbations implied by its peculiar classification.
NGC 5247 is also a Seyfert 2 galaxy, meaning it hosts an active galactic nucleus obscured from direct view. While the nucleus appears visually modest, this classification indicates energetic processes occurring at its core, contributing to the ionization of gas in the central regions and potentially influencing the inner spiral structure
Overall, NGC 5247 presents a balance between large-scale order and localized complexity—a textbook grand design spiral whose fine structure reveals the ongoing interplay between star formation, gas dynamics, and nuclear activity
Imaged in LRGB on the ASA Astrosysteme AZ 1500 at Observatorio El Sauce, Chile.
Image Acquisition and Processing: Mike Selby