SS Virginis: An Orange-Red Variable and Carbon Star in Virgo

SS Virginis (SS Vir) is a variable and carbon star located in the constellation Virgo, best viewed in springtime.

Astronomers classify SS Virginis as a Mira variable. This particular type of star pulsates by shining and dimming over a period that exceeds 100 days. It is named after the star in Cetus named Mira, which is the prototype of this type of star.

SS Virginis pulsates between a magnitude of 9.5 to 7.4 within a period of 361 days.¹ This pretty orange-red star is also known as a carbon star, classified as a C6, 3e spectral type. Why, you may ask, is SS Virginis called a carbon star? In a nutshell, the star’s atmosphere has a higher concentration of carbon than oxygen, resulting in the reddish color we see.

My Observations

Some online articles classify SS Virginis as a dark red carbon star, while others describe it as orange-red. I agree with the latter. I expected the star to be a deep red, but it appears more orange-red this evening. Light pollution washes out nearby faint stars, but one brighter white star lies to the left of the scarlet star.

Key Stats

Constellation	Virgo
Best Viewing	Spring
Visual Magnitude	+7.4 to +9.5
Milky Way Location	Orion Spur
My Viewing Grade	B+
Designations	SS Vir, HD 108105

Sources and Notes

The banner with a red star is based on an image in the public domain in the United States because it was solely created by NASA. View source file.

¹SS Virginis. aavso. (n.d.). https://www.aavso.org/lcotw/ss-virginis

Sketch by Wayne McGraw