The Chrysalis Opens? Photometry from the Eta Carinae HST Treasury Project, 2002-2006

Abstract

During the past decade Eta Car has brightened markedly, possibly indicating a change of state. Here we summarize photometry gathered by the Hubble Space Telescope as part of the HST Treasury Project on this object. Our data include STIS/CCD acquisition images, ACS/HRC images in four filters, and synthetic photometry in flux-calibrated STIS spectra. The HST's spatial resolution allows us to examine the central star separate from the bright circumstellar ejecta. Its apparent brightness continued to increase briskly during 2002--06, especially after the mid-2003 spectroscopic event. If this trend continues, the central star will soon become brighter than its ejecta, quite different from the state that existed only a few years ago. One precedent may be the rapid change observed in 1938--1953. We conjecture that the star's mass-loss rate has been decreasing throughout the past century.

arXiv commentAccepted for publication in AJ. 31 pages including: 6 Figures and 5 Tables

References in corpus (8)

• The Photometric Performance and Calibration of the HST Advanced Camera For Surveys
• Latitude-dependent effects in the stellar wind of Eta Carinae
• The 2003 Shell Event in eta Carinae
• On the He II Emission In Eta Carinae and the Origin of Its Spectroscopic Events
• A Change in the Physical State of $\eta$ Carinae?
• Variability of eta Carinae III
• Eta Carinae's Brightness Variations Since 1998: HST Observations of the Central Star
• Variable Unidentified Emission Near 6307 AA in Eta Carinae

Cited by in corpus (27)

• High-excitation emission lines near eta Carinae, and its likely companion star
• Constraints on decreases in Eta Carinae's mass loss from 3D hydrodynamic simulations of its binary colliding winds
• A multispectral view of the periodic events in eta Carinae
• Unmasking the Supernova Impostors
• The Early Spectra of Eta Carinae 1892 to 1941 and the Onset of Its High Excitation Emission Spectrum
• Herschel far-infrared observations of the Carina Nebula complex II: The embedded young stellar and protostellar population
• A Sea Change in Eta Carinae
• Secular Changes in Eta Carinae's Wind 1998-2011
• The three-dimensional structure of the Eta Carinae Homunculus
• 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
• The fossil wind structures of Eta Carinae: changes across on 5.54-year cycle
• A Lighthouse Effect in Eta Carinae
• Recovery from Giant Eruptions in Very Massive Stars
• Distinguishing Circumstellar from Stellar Photometric Variability in Eta Carinae
• Eta Carinae's 2014.6 Spectroscopic Event: The Extraordinary He II and N II Features
• Penetrating the Homunculus -- Near-Infrared Adaptive Optics Images of Eta Carinae
• Accretion onto the Companion of Eta Carinae During the Spectroscopic Event. IV. the Disappearance of Highly Ionized Lines
• Mid-Cycle Changes in Eta Carinae
• Mid-infrared evolution of eta Car from 1968 to 2018
• Eta Carinae's Declining Outflow Seen in the UV, 2002-2015
• Spectroscopic Signatures of the Vanishing Natural Coronagraph of eta Carinae
• Eta Carinae -- Physics of the Inner Ejecta
• Interferometric observations of eta Carinae with VINCI/VLTI
• The Altered State of $\eta$Carinae: HST's Photometric Record 1998--2021
• Precession and Nutation in the eta Carinae binary system: Evidences from the X-ray light curve
• Long-term evolution in ionization of ejecta illuminated by Eta Carinae