NGC 2683

Lore & Background

NGC 2683 was discovered by the astronomer William Herschel on February 5, 1788. It is a field spiral galaxy in the northern constellation of Lynx, viewed nearly edge-on from Earth. The reddened light from its center appears yellowish due to intervening gas and dust within its outer arms. Its apparent magnitude is 10.6, making it not visible to the human eye without a small telescope.

While usually considered an unbarred spiral galaxy, recent research suggests it may in fact be a barred spiral galaxy; its bar is hard to see due to its high inclination. Further support for the presence of a bar stems from the X-shaped structure seen near its centre, which is thought to be associated with a buckling instability of a stellar bar. NGC 2683 is both smaller and less luminous than the Milky Way, with very little neutral hydrogen or molecular hydrogen and a low luminosity in the infrared, which suggests a currently low rate of star formation.

The galaxy is rich in globular clusters, hosting about 300 of them—twice the number found in the Milky Way. Due to its vast distance and complexity, its mass has not been calculated as accurately as it could be, though its volume and vector motions are reasonably well known. Several satellite galaxies are known in the vicinity, including KK 69 (a dwarf transitional galaxy with a Holmberg diameter of 12,000 light-years), KK 70 (about half that diameter), and two additional dwarf galaxies: N2683dw1 (dwarf irregular) and N2683dw2 (dwarf spheroidal).

Reader's Guide

NGC 2683 holds significance as a nearby field spiral galaxy studied for its edge-on orientation, which provides a clear view of its structure and dust lanes. Its nickname, the 'UFO Galaxy,' reflects its distinctive appearance. The galaxy's uncertain classification—whether it is unbarred or barred—highlights ongoing research into spiral galaxy morphology, especially when high inclination obscures features like bars. The X-shaped structure near its centre offers evidence of a buckling instability in a stellar bar, a phenomenon relevant to understanding galactic dynamics. Its low star formation rate and scarcity of neutral and molecular hydrogen contrast with more active galaxies, making it a useful object for studying quiescent spiral evolution. The rich globular cluster system, numbering about 300, is notable for being twice that of the Milky Way, and the presence of several satellite galaxies—including the transitional dwarf KK 69—provides context for galaxy group interactions. The galaxy's distance remains somewhat uncertain, with estimates ranging from 16 to 30 million light-years, reflecting the challenges of measuring extragalactic distances. Its legacy includes being a target for amateur astronomers due to its brightness (magnitude 10.6) and for professional studies of edge-on galaxies, globular cluster populations, and low-luminosity spiral systems.

Did You Know?

• It hosts about 300 globular clusters, twice the number found in the Milky Way.
• The galaxy is receding from Earth at 410 km/s and from the Galactic Center at 375 km/s.
• Its largest satellite galaxy, KK 69, has a Holmberg diameter of 12,000 light-years.