4 Cygni

Lore & Background

4 Cygni was announced as a low amplitude variable star by John Ernest Winzer in his 1974 Ph.D. thesis. It received its variable star designation, V1741 Cygni, in 1981. The visible component, 4 Cygni A, is an Alpha2 Canum Venaticorum variable that varies by 0.02 magnitude over a period of 0.68674 days. The star displays an overabundance of iron in the visual spectrum and appears helium-weak in the ultraviolet, consistent with its classification as a silicon star.

Reader's Guide

4 Cygni's significance lies in its role as a chemically peculiar star of the silicon type, a class of magnetic B-type stars that exhibit strong, organized magnetic fields and surface abundance anomalies. As an Alpha2 Canum Venaticorum variable, its small brightness variations are tied to its rotation and the distribution of chemical spots on its surface. The system's binary nature, with a 35-day orbital period and notable eccentricity, adds to its interest for studies of stellar evolution and magnetic activity. Its distance of about 560 light years and relatively young age of 145 million years place it among intermediate-mass stars that have not yet left the main sequence. The star's magnetic field, measured as an average quadratic field strength, and its enhanced iron lines make it a valuable object for understanding the physics of magnetic fields in early-type stars. The discovery of its variability in a doctoral thesis and its subsequent formal designation highlight the ongoing process of identifying and cataloging variable stars.

Did You Know?

• Its visible component is a silicon star, showing an overabundance of iron in the visual spectrum and helium weakness in the ultraviolet.
• The star varies by only 0.02 magnitude over a period of 0.68674 days, making it a low-amplitude Alpha2 Canum Venaticorum variable.
• 4 Cygni has four times the mass of the Sun and five times its radius, radiating 501 times the Sun's luminosity.