A luminous disk split by shadow, with a disturbed spiral companion caught in a close gravitational encounter
NGC 5078 is an edge-on spiral galaxy classified as SA(s)a? edge-on in the constellation Virgo. Its bright central bulge shines through a prominent dust lane that is notably uneven and asymmetric, hinting at a disk that is no longer in perfect equilibrium. Subtle warping and flaring are visible along the outer edges of the disk, and the surrounding halo shows a slight imbalance in brightness—signatures of gravitational disturbance rather than a pristine, isolated structure
At a distance of approximately 118.7 million light-years, NGC 5078 spans about 4.0 × 1.9 arcminutes, corresponding to a physical size of roughly 138,000 × 66,000 light-years. While its overall form resembles a classic edge-on spiral, the irregularities in its dust lane and outer disk reveal the effects of tidal forces acting over time.
Just below it lies IC 879, a barred spiral galaxy classified as SB(s)ab pec, whose structure is clearly disturbed. Located at about 129.2 million light-years, it measures approximately 1.4 × 1.2 arcminutes, or about 53,000 × 45,000 light-years. Its spiral pattern is loose and asymmetric, with an uneven light distribution and enhanced star-forming regions that give it a slightly bluer appearance. These features point to tidal stretching and interaction-driven activity rather than a stable, symmetric spiral
Together, NGC 5078 and IC 879 form an interacting pair in an early to intermediate stage of gravitational encounter. The distortions in NGC 5078—its asymmetric dust lane, warped disk, and uneven halo—align with the position of IC 879, suggesting a three-dimensional interaction rather than a simple planar pass. Although no prominent tidal bridge or extended tails are visible, both galaxies already show clear structural responses to each other’s gravitational influence, offering a detailed view of galactic evolution in progress
Imaged in LRGB on the ASA Astrosysteme AZ 1500 at Observatorio El Sauce, Chile.
Image Acquisition and Processing: Mike Selby