We report the recovery of a spectroscopic event in h Carinae in 1997/1998 after a prediction by Damineli in 1996. A true periodicity with days (0.2% uncertainty) is obtained. The line intensities and the P = 2020 ‫ע‬ 5 radial velocity curve display a phase-locked behavior, implying that the energy and dynamics of the event repeat from cycle to cycle. This rules out S Doradus oscillation or multiple shell ejection by an unstable star as the explanation of the spectroscopic events. A colliding-wind binary scenario is supported by our spectroscopic data and by X-ray observations. Although deviations from a simple case exist around periastron, intensive monitoring during the next event (mid-2003) will be crucial to our understanding of the system.

We present new observations of 71 Carinae, strongly suggesting that it is a binary system. High dispersion measurements of the broad Pay emission line show periodic radial velocity variations that are nicely explained by a star in a highly eccentric orbit. Velocity characteristics of the system imply massive components, in accord with the luminosity and spectral characteristics. Strong and variable wind-wind interactions are predicted to take place in v Car on the basis of the orbital elements and physical characteristics of the components. The low excitation event predicted for the end of 1997 is underway, confirming the high coherence of the 5.52 year cycle and adding confidence to 77 Car as a binary system. We associate this event with periastron passage. A conclusive demonstration of the binary orbit is still pending, but the present work has the advantages of bringing this mysterious object within a stellar evolution framework, and, for the first time in its history, predictions suitable for testing against future observations. 0 1997 Elsevier Science B.V.

Abstract. Quantitative measurements of line parameters in the spectrum of η Carinae are presented for both the broad and narrow line components. A total of 655 spectral features were measured in the spectral range 3850Å to 11000Å, giving a comprehensive view of the behavior of atomic transitions ranging from a few to tens of electron volts. The spectrum on the phase of maximum intensity in the high excitation lines (1995) is compared with that on minimum intensity (June 1992), showing that at this phase the high excitation lines disappear but the broad components of low excitation lines strengthens. We reject a number of previous line identifications and propose several new ones, including Fe ii,, and the near-infrared Ca ii triplet. Some lines commonly used to diagnose density, temperature, chemical composition, and reddening were found to be blended, urging a revision of the results based on previous data. The existence of double-peaked lines, suggested in previous papers, is ruled out. In the case of hydrogen lines, the apparent doublepeaks are shown to be real absorption components. The velocity field in the inner 2 around the central star shows additional components previously unknown. The phases of high and low excitation in η Carinae are discussed in light of a recently proposed binary system. We suggest a temperature T ∼ 16000 K for the primary star, what indicates that it is close to the beginning of the core helium-burning evolutionary stage.