The visual magnitude of ? Virginis (Spica) has been measured over a period of 3 months. The light shows a 4.17036 hr period of amplitude 1.6 per cent showing that the primary of the binary star system is a ? Canis Majoris variable. There is, in addition, a 3 per cent variation in brightness over the 4.014 day orbital period, which can be accounted for by aspect changes of the tidally distorted primary. Eclipses, if they occur, are probably less than 0.5 per cent in depth.
- 1 - natural sciences ; 2 - physics & astronomy ; 3 - astronomy & astrophysics
- 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Space and Planetary Science
- 1 - Physical Sciences ; 2 - Physics and Astronomy ; 3 - Astronomy and Astrophysics