NGC 1466

Lore & Background

NGC 1466 was discovered by John Herschel on November 26, 1834. John Dreyer described it as 'pF, pS, iR, glbM, *7 f', meaning 'pretty faint, pretty small, irregular round, gradually a little brighter middle, with a 7th magnitude star nearby'. When viewed through a small telescope, it appears as a 'faint, small, unresolved and difficult' target with an angular size of 1.9 arc minutes. The cluster has an integrated visual magnitude of 11.4.

The cluster has a reddening corrected distance modulus of 18.43±0.15, corresponding to a distance of 48.5 kpc. Its mass is about 140,000 times the mass of the Sun, and it is an old cluster with an estimated age of 13.1 billion years. In photographs, the cluster spans an apparent size of 3.50 arc minutes. The core radius has an angular size of 10.7±0.4 arc seconds, while the half-light radius is 24.3 arc seconds.

As of 2011, there are 49 known and one candidate RR Lyrae variable stars in the cluster, including eight RRd (double-mode) variables. The average periods are 0.591 days for RR Lyrae type ab and 0.335 days for RR Lyrae type c, consistent with an Oosterhoff-intermediate classification. Twelve other variables have been identified, including two long-period variables and a Cepheid variable.

Reader's Guide

NGC 1466 is significant as a globular cluster in the outskirts of the Large Magellanic Cloud, providing a window into the early history of that satellite galaxy. Its age of 13.1 billion years makes it one of the older known clusters, offering clues about star formation in the early universe. The cluster's population of RR Lyrae variable stars—49 known plus one candidate as of 2011—is particularly notable for its Oosterhoff-intermediate classification, which helps astronomers understand the properties of variable stars in different environments. The presence of double-mode RR Lyrae variables, long-period variables, and a Cepheid variable adds to its value as a laboratory for stellar evolution studies. Its discovery by John Herschel in 1834 and its description by John Dreyer place it within the historical cataloging of deep-sky objects. The cluster's distance of 48.5 kpc and mass of 140,000 solar masses provide key parameters for modeling the dynamics and composition of the Large Magellanic Cloud's outer regions.

Did You Know?

• It contains 49 known RR Lyrae variable stars and one candidate as of 2011.
• Its integrated visual magnitude is 11.4.