Our photometric study shows that CR Cas is a detached eclipsing binary whose components are early B type, main sequence stars. In the recent compilation of Andersen (1991), it is shown that only three eclipsing binaries with components earlier than B2 have their astrophysical parameters determined with an accuracy better than 2%. In three spectra of CR Cas obtained by Popper (1996) no separate lines from both components appear to be measurable, but he states that with this small number of spectra no firm conclusion can be reached. Further spectroscopic work would be of great value in order to discern whether CR Cas is a double-lined eclipsing binary. If this is the case, CR Cas would be a good candidate for the accurate determination of the stellar astrophysical parameters in a range of masses in which the available systems are very scarce.
Acknowledgements
The 1.5 m telescope at Calar Alto is operated by the Observatorio Astronomico Nacional. We want to express our gratitude to the observatory staff. This work has been supported by the Spanish Comisión Interministerial de Ciencia y Tecnologıa (PB90-0001-C02).