Wolf 424

Wolf 424 is a binary star system comprising two red dwarf stars at a distance of approximately 14.2 light years from the Sol System. It is located in the constellation Virgo, between the stars ε Virginis and ο Virginis. The Wolf 424 system is considered to be within the Sol System Neighborhood The close binary nature of this star was discovered for Earth by Dutch American astronomer Dirk Reuyl in 1941, based upon an elongation of the star found in photographs.

The two stars in the Wolf 424 system orbit about each other with a semi-major axis of 4.1 AU and an eccentricity of 0.3. The stars have an orbital period of 15.5 years and have a combined apparent magnitude of about 12.5.

Wolf 424A is a cool main sequence red dwarf star of approximately 0.14 solar masses (147 Jupiters) and a radius of 0.17 solar radii. Its companion, Wolf 424B, is a cool main sequence red dwarf star of approximately 0.13 solar masses (136 Jupiters) and a radius of 0.14 solar radii. They are two of the dimmest known objects within 15 light years of the Sun.

In 1967, it was discovered that both are flare stars that undergo random increases in luminosity. The system has been designated FL Virginis, and may experience sunspot activity.

The stars may undergo variation in the level of flare activity over periods lasting several years.

Wolf 424 A This very cool, main sequence red dwarf (M5.5Ve) is one of our Sun's dimmest stellar neighbors within 15 ly, with only 14/100,000th of Sol's visual luminosity. If our Sun, Sol, were replaced by Wolf 424 A, then an observer on Earth would need a telescope to see its round shape clearly, and daylight would be very dim with not much more than ten times the brightness of full moonlight with Sol. The star has only 12 to 14 percent of Sol's mass

Wolf 424 B The companion star is a very cool, main sequence red dwarf (M5.5 or M7 Ve). It has about 12 to 13 percent of Sol's mass with about 14 percent of its diameter but only 8/100,000th of its luminosity. Some of the star's dimness is due to sunspots which often lead to stellar flaring. Indeed, Wolf 424 B is a Flare Star (that has been designated with the variable star name FL Virginis) and so can brighten dramatically from time to time. For Union System Info see:    FL Virginis