The 5.52 Year Cycle of Eta Carinae: BeppoSAX Detection of Variable Hard (> 10 keV) X-Ray Emission

@inproceedings{Rebecchi1996The5Y,
  title={The 5.52 Year Cycle of Eta Carinae: BeppoSAX Detection of Variable Hard (> 10 keV) X-Ray Emission},
  author={S. Rebecchi and Rodolfo Viotti and Paola Grandi and L. Angelo Antonelli and Michael F. Corcoran and Augusto Damineli and Corinne Rossi},
  year={1996}
}
I have discovered spectroscopic variations correlated with the photometric near-infrared (NIR) light curve in η Carinae. The fading of the high-excitation lines is coincident with the peaks in the NIR light curve, strongly resembling an S Doradus type of variability. The cycle, however, is highly stable, and the 5.52 yr period fits well all the shell episodes reported in the last 50 years. This period also recovers the three historical bursts of the last century, in phase with the present low… Expand
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The nebula around the luminous blue variable (LBV) η Car is extremely N rich and C and O poor, which is indicative of CNO-cycle products. On the other hand, the recent Hubble Space Telescope-GoddardExpand
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References

SHOWING 1-10 OF 21 REFERENCES
Intense radio outburst from the supermassive star Eta Carinae
On five occasions between 1992 June 29 and 1994 May 3, we have used the Australia Telescope Compact Array (ATCA) to image Eta Carinae at a wavelength of 3 cm and a resolution of 1 arcsec. TheseExpand
First Detection of X-Ray Variability of eta Carinae
Recent ROSAT Position Sensitive Proportional Counter (PSPC) observations for the first time unequivocally reveal the presence of a compact source of hard X-ray emission centered on the peculiar starExpand
On the continuum and the absolute magnitude of eta Carinae
The excitation temperature, colour excess and continuum of η Car in the visible and near ultraviolet have been determined from the study of the excitation of the ionized iron emission lines. TheExpand
The Luminous Blue Variables: Astrophysical Geysers
Some of the most luminous stars have sporadic, violent mass-loss events whose cuases are not understood. These evolved hot stars are called Luminous Blue Variables (LBV's), and their instability mayExpand
The spectral and spatial distribution of radiation from Eta Carinae. II High-resolution infrared maps of the Homunculus
The spectral and spatial distribution of radiation from Eta Carinae II and high-resolution infrared maps of the Homunculus are presented. It is found that at the resolution of 1.1 arcsec the sourceExpand
Proper motions in the outer shell of eta Carinae
Proper motions were determined for discrete features in the complex outer shell of eta Carinae, from plates taken at Radcliffe Observatory during 1949--1950 and at Cerro Tololo Inter-AmericanExpand
THE 1981 MASS-LOSS PHASE OF ETA CARINAE
A visual-region coude spectrogram of Eta Car taken in 1981 May is described, and the portion of the spectrum containing H-alpha is reproduced. This was taken during one of Eta Car's "abnormal"Expand
The homunculus of Eta Carinae: An interacting stellar winds paradigm
We simulate the origin and evolution of the bipolar nebula surrounding Eta Car using numerical two-dimensional gasdynamic models. The generalized interacting stellar winds scenario, wherein a stellarExpand
Time variations of the H-alpha line profile from the core of Eta Carinae
Observations avec une forte resolution du profil de la raie Hα provenant du cœur de η Carinae. On note des variations de la forme du profil sur des echelles de temps inferieures a un an. L'analyseExpand
The near-infrared spectrum of eta Carinae.
Spectroscopie de 1,0 a 2,3 μm de cette etoile lumineuse. On a enregistre plus de 80 raies d'emission, et identifie 90%, pour la plupart des especes egalement vues a des longueurs d'onde optiques.Expand
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