eta CARINAE

DAMINELI A.; STEINER J.; GROH J. H.; FRAGA L.; TEODORO M.; FERNÁNDEZ LAJÚS E.; GONZALEZ F.; GAMEN R.; BORGES FERNANDES M.; PEREIRA C. B.; TORRES C. A. P. C. O.; ZEVALLOS HERENCIA M. I.; MORRELL N.

IAU Circular

International Astronomical Union, Central Bureau for Astronomical Telegrams

Lugar: Cambridge; Año: 2009 vol. 9011 p. 1 - 1

0081-0304

A. Damineli, Instituto de Astronomico e Geofisico,Universidade de Sao Paulo, reports that spectroscopic observationscollected at the Southern Astrophysical Research Telescope (LaSerena, Chile) by Damineli, J. Steiner, J. H. Groh, and L. Fragaindicate that eta Car reached the phase of minimum excitation onJan. 11, on schedule with the predictions (Damineli et al. 2008,MNRAS 384, 1649). This supports the 2023-day period and the binarynature of the system. The doubly ionized forbidden lines and thenarrow components of He I and [N II] lines disappeared from thespectrum. P-Cyg absorption in permitted transitions (He I, H I,and Fe II) became more enhanced. The He II 468.6-nm line, whichhad been increasing rapidly through 2008 December, has nowcollapsed abruptly to about 300 milliAngstroems, the same level asit was a month before. The radial velocity reached -3204 km/s andseems to be still shifting toward the blue. Such results arecorroborated by observations taken at Observatorio do Picos dosDias (Brazil) by M. Teodoro; at the Complejo Astronomico elLeoncito (Argentina) by E. F. Lajuz, F. Gonzalez, and R. Gamen; atthe European Southern Observatory 2.2-m telescope by M. BorgesFernandes, C. B. Pereira, C. A. P. C. O. Torres, and M. I. ZevallosHerencia; and at Las Campanas Observatory by N. Morrell. Figuresand additional details can be found at the following website URL:www.etacarinae.iag.usp.br.