41 Tauri
A chemically peculiar variable star in Taurus.
41 Tauri, also known by its Flamsteed designation, lies in the zodiacal constellation Taurus. It is a single-lined spectroscopic binary system. With a visual magnitude of 5.19, it can be seen without a telescope from brighter suburban skies, as defined by the Bortle scale. Parallax measurements place it roughly 404 light years from the Sun.
This star is chemically peculiar. American astronomer William Morgan first classified it as a silicon star in 1933. Its spectrum shows an overabundance of heavier elements, particularly silicon and gallium. These abundances likely result from the star's magnetic field, which concentrates these elements in the outer atmosphere. In 1962, Karl D. Rakos announced its variability based on observations from 1960 and 1961. It is an α² Canum Venaticorum-type variable star, with its magnitude fluctuating from 5.15 to 5.22. These brightness changes are probably caused by large spots or rings on the observed side of the star.
The star and its companion orbit each other closely, completing one orbit in a week with an eccentricity of 0.18. The primary star's rotation has become locked to its orbit, so one face always points toward the companion. The abundances of gallium and silicon vary in a sinusoidal pattern matching this orbital period.
The primary star has about 2.9 times the Sun's mass, 3.5 times its radius, and emits 190 times its luminosity. Its photosphere has an effective temperature of 12,600 K, giving it the blue-white hue of a B-type star.
- Flamsteed designation
- 41 Tauri
- Visual magnitude
- 5.19
- Distance
- approximately 404 light years
- Variable star type
- α² Canum Venaticorum
- Magnitude range
- 5.15 to 5.22
- Orbital period
- one week
- Orbital eccentricity
- 0.18
Lore & Background
41 Tauri was first classified as a silicon star by American astronomer William Morgan in 1933. Its spectrum shows an overabundance of heavier elements, particularly silicon and gallium, likely due to the star's magnetic field concentrating these elements in its outer atmosphere. In 1962, Karl D. Rakos announced that 41 Tauri is a variable star based on observations made in 1960 and 1961. It varies in magnitude from 5.15 to 5.22, with variations attributed to large spots or rings on the observed side of the star. The primary star has a rotation period locked to its orbital period of one week, and the abundances of gallium and silicon vary sinusoidally with that period.
Reader's Guide
41 Tauri is significant as an α² Canum Venaticorum variable star, a class of chemically peculiar stars whose brightness variations are linked to surface inhomogeneities. Its classification as a silicon star by William Morgan in 1933 marked an early recognition of chemical peculiarity in stellar spectra. The discovery of its variability by Karl D. Rakos in 1962 added to the understanding of how magnetic fields and rotation produce observable changes in such stars. The star's locked rotation and orbital period, along with the sinusoidal variation of element abundances, provide a clear example of how tidal forces and magnetic fields shape the atmospheres of close binary systems. Its visibility to the naked eye from suburban skies makes it accessible for amateur observers interested in variable stars.
Did You Know?
- 41 Tauri is also designated GS Tauri.
- Its rotation period is locked to its orbital period of one week.
- The star's spectrum shows an overabundance of silicon and gallium.
More in Variable Stars, Part 5 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced