The Line Profile Variations of eta Carinae Through the 2009.0 Spectroscopic Event

RICHARDSON N. D.; GIES D.; HENRY T.; FERNÁNDEZ LAJÚS E.; OKAZAKI A.

Washington DC

Congreso; American Astronomical Society Meeting 215; 2010

American Astronomical Society

We report on high resolution echelle spectroscopy of the 2009.0 spectroscopic event of eta Carinae that we collected via SMARTS observations using the CTIO 1.5 m telescope and echelle spectrograph. Our observations were made almost every night over a two month interval around the predicted minimum of eta Car. We observed a dramatic fading of the H-alpha line emission that reached a minimum six days after the X-ray minimum. About 15 days prior to the H-alpha flux minimum, the H-alpha profile exhibited the emergence of a broad, P Cygni type, absorption component (near a Doppler shift of -500 km/s and a narrow absorption component (near -144 km/s and probably associated with intervening gas from the Little Homunculus Nebula). We also observed the He I 5876, 6678, and 7065 lines. The line profile variations are similar to those observed during previous events, and the temporal variations are consistent with qualitative expectations about changes in the primary star's stellar wind that result from the wind - wind collision with a massive binary companion.