Astron. Astrophys. 364, 225-231 (2000)

An investigation of the multiple star Zeta Cnc by a lunar occultation ^*

A. Richichi ^**

European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany

Received 3 July 2000 / Accepted 19 September 2000

Abstract

We analyze and discuss a lunar occultation of the multiple star  Cnc, obtained in the near-infrared. The long-sought D component, recently imaged with the help of adaptive optics also by Hutchings et al. (2000), is clearly seen in the occultation light curve, and we determine its projected separation and brightness ratio with high accuracy. Regarding the suggested binary nature of D, we provide an estimate of the upper limit of its separation. In addition, we find evidence for a further component in the system. The signal from this latter is at the limit of detection, but it is confirmed by three independent data analysis methods. We discuss the astrometry and photometry of the system, and the implications for the mass and spectral characteristics of the components. With a projected separation of , the proposed E component could form a close pair with  Cnc C. However, at the present stage we have to consider it only as tentative, and further observations by large telescopes or large interferometric facilities will be needed to confirm and study it in detail.

Key words: astrometry occultations stars: binaries: close stars: binaries: visual stars: fundamental parameters stars: individual:

* Based on observations collected at TIRGO (Gornergrat, Switzerland), and at Calar Alto (Spain). TIRGO is operated by CNR-CAISMI Arcetri, Italy. Calar Alto is operated by the German-Spanish Astronomical Center.
** On leave from Osservatorio Astrofisico di Arcetri

Send offprint requests to: A. Richichi (arichich@eso.org)

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
• 3. Data analysis and results
• 4. Discussion
• 5. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: December 15, 2000
helpdesk.link@springer.de