The H-alpha Variations of eta Carinae During the 2009.0 Spectroscopic Event

Abstract

We report on H-alpha spectroscopy of the 2009.0 spectroscopic event of eta Carinae 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 significant fading of the line emission that reached a minimum seven days after the X-ray minimum. About 17 d 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). All these features were observed during the last event in 2003.5 and are probably related to the close periastron passage of the companion. We argue that these 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 and from atmospheric eclipses of the companion.

21 pages, 6 figures, 1 table, accepted to AJ

References in corpus (6)

• The periodicity of the eta Carinae events
• 3D modelling of the colliding winds in Eta Carinae - evidence for radiative inhibition
• Chemical evolution of galaxies. I. A composition-dependent SPH model for chemical evolution and cooling
• A multispectral view of the periodic events in eta Carinae
• The Eta Carinae optical 2009.0 event, a new "eclipse-like" phenomenon
• Eta Carinae across the 2003.5 Minimum: Analysis in the visible and near infrared spectral region

Cited by in corpus (20)

• Spiralling out of control: 3D hydrodynamical modelling of the colliding winds in $\eta$Carinae
• Constraining the Absolute Orientation of Eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission
• On the influence of the companion star in Eta Carinae: 2D radiative transfer modeling of the ultraviolet and optical spectra
• He II $\lambda$4686 emission from the massive binary system in $\eta$ Car: constraints to the orbital elements and the nature of the periodic minima
• A Sea Change in Eta Carinae
• Secular Changes in Eta Carinae's Wind 1998-2011
• Eta Carinae's 2014.6 Spectroscopic Event: Clues to the Long-term Recovery from its Great Eruption
• Critical Differences and Clues in Eta Car's 2009 Event
• Modelling the asymmetric wind of the luminous blue variable binary MWC 314
• To $v_{\infty }$ and beyond! The He I absorption variability across the 2014.6 periastron passage of $\eta$ Carinae
• VLTI-AMBER velocity-resolved aperture-synthesis imaging of Eta Carinae with a spectral resolution of 12000. Studies of the primary star wind and innermost wind-wind collision
• Uncovering the orbital dynamics of stars hidden inside their powerful winds: application to $\eta$ Carinae and RMC 140
• The Optical Wind Line Variability of $\eta$ Carinae During the 2009.0 Event
• Spectroscopy, MOST Photometry, and Interferometry of MWC 314: Is it an LBV or an interacting binary?
• Spectroscopic Signatures of the Vanishing Natural Coronagraph of eta Carinae
• The orbital kinematics of eta Carinae over three periastra with a possible detection of the elusive secondary's motion
• Eta Carinae -- Physics of the Inner Ejecta
• Luminous Blue Variables
• Changes in the Na D${}_1$ Absorption Components of $\eta$ Carinae Provide Clues on the Location of the Dissipating Central Occulter
• Long-term evolution in ionization of ejecta illuminated by Eta Carinae