SS Virginis is a Mira variable star that appears with a strong red hue. It varies in magnitude from a minimum of 9.5 to a maximum of 7.4 over a period of 361 days. It is also considered to be a

semiregular variable star In astronomy, a semiregular variable star, a type of variable star, is a giant or supergiant of intermediate and late (cooler) spectral type showing considerable periodicity in its light changes, accompanied or sometimes interrupted by various irre ...

, as its minimum and maximum magnitude are themselves variable over a period of decades. Its spectral class is C6₃e. Because it is so rich in

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

, SS Virginis is classified as a

carbon star A carbon star (C-type star) is typically an asymptotic giant branch star, a luminous red giant, whose atmosphere contains more carbon than oxygen. The two elements combine in the upper layers of the star, forming carbon monoxide, which consumes mos ...

, along with stars like T Geminorum. SS Virginis, like all carbon Mira variables, has a

hydrogen-alpha H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air and 656.46 nm in vacuum; it occurs when a hydrogen electron falls from its third to second lowest energy level. H-alpha ...

emission line that varies widely, synchronized with the overall variations in light. The hydrogen-alpha emission line becomes far more prominent as the star becomes brighter. Observations made in the

near-infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

spectrum indicate that it has a radius of 500 solar radii, and its temperature is between 2405 and 2485

kelvin The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and phys ...

s. The location of SS Virginis is two degrees north-following of η Virginis (Eta Virginis, ''Zaniah'').

References

;Citations ;References * {{DEFAULTSORT:SS Virginis Virgo (constellation) Mira variables Virginis, SS 120212 108105 Durchmusterung objects