S Cancer ( lat. S Cancri , S Cnc) is a completely eclipsing variable star of the Algol type . It is located in the constellation Cancer , at a distance of about 1000 light-years from the Sun. Outside the eclipse phases, the apparent magnitude is 8.35 m (not visible to the naked eye), and decreases to 10.3 m during the eclipse. The orbital period of the pair is 9.484 days. The main component of the pair is a white-blue star of the main sequence of class B9 with a surface temperature of 10 190 K , a radius of 2.23 R ☉ and a mass of 2.42 M ☉ . Its satellite is an orange giant or a subgiant of spectral class from G9 to K0 with a surface temperature of 4858 K , a radius of 4.74 R ☉ and a mass of 0.23 M ☉ . The mass ratio of hot and cold stars is unusually small, 0.078 ± 0.016. Signs of the flow of matter between the stars are not observed. The distance between them is 18.159 × 10 6 km , or 26.09 R ☉ . The luminosity of the hot and cold stars is 1.69 and 1.08 L ☉, respectively.
( Age J2000.0 )
|Distance||1,025 ± 114 St. years (314 ± 35 pc )|
|Visible magnitude ( V )||8.35 |
|Radial velocity ( R v )||10 ± 4,5  km / s|
|Own movement (μ)||RA: −19.430 (74) |
Dec: +2,442 (38) 
|Parallax (π)||3.18 ± 0.35  mas|
|Absolute magnitude (V)||0.87|
|Spectral class||B9V + K0IV|
|Variability||eclipsing type Algol|
|Weight||2.42 + 0.23 M ☉|
|Temperature||10 190 K / 4858 K|
|Luminosity||1.69 + 1.08 L ☉|
|Metallicity||[M / H] =?|
- Cancer constellation star list
- Irwin JB The differential limb darkening of S Cancri // Publications of the Goethe Link Observatory of Indiana University. - 1963. - P. 1104-1111. - .
- Linnell AP, Proctor DD A Computer Solution of the Light Curves of S Cancri (Eng.) // The Astrophysical Journal. - 1971. - Vol. 164. - P. 131-136. - DOI : 10.1086 / 150824 . - .
- Olson EC, Etzel PB S Cancri - New multicolor photometric observations and solutions, and spectroscopic observations (Eng.) // The Astronomical Journal. - 1993. - Vol. 106. - P. 1162-1173. - DOI : 10.1086 / 116715 . - .