NOAO >   Observing Info >   Approved Programs >   2013A-0349

# Proposal Information for 2013A-0349

PI: Armin Rest, Space Telescope Science Institute, arest@stsci.edu
Address: 3700 San Martin Dr., Baltimore, MD 21218, USA

CoI: Federica Bianco, LCOGT
CoI: Ryan Chornock, Harvard/CfA
CoI: Thomas Matheson, NOAO
CoI: Jose Luis Prieto, Princeton University
CoI: Brendan Sinnott, McMaster University
CoI: Chris Smith, NOAO
CoI: Nathan Smith, Steward Observatory
CoI: Nolan Walborn, Space Telescope Science Institute
CoI: Doug Welch, McMaster University

Title: Spectrophotometric Time Series of \eta Carinae's Great Eruption

Abstract: \eta Carinae (\eta Car) is one of the most massive binaries in the Milky Way \citeDH97, and its expanding circumstellar nebula has been studied in detail \citeSmith06. It was seen as the second brightest star in the sky during its 1800s Great Eruption'' (GE), but only visual estimates of its brightness were recorded \citeSF11. In 2011 we discovered several light echoes (LEs) which appear to be from the 1838-1858 \eta Car eruptions \citeRest12_eta. Subsequent spectroscopic follow-up revealed that its outburst spectral type was most similar to those of G-type supergiants, rather than reported LBV outburst spectral types of F-type (or earlier) \citeRest12_eta. These differences between the GE and the extragalactic transients presumed to be its analogues raise questions about traditional scenarios for the outburst and warrant continued monitoring of its echoes. We propose to obtain a spectrophotometric time series of the GE from \it different directions, allowing the original eruption of \eta Car to be studied as a function of time as well as latitude. A detailed spectroscopic study of the LEs of \eta Car could help us understand (episodic) mass- loss in the most massive evolved stars and their connection to the most energetic core-collapse supernovae that are being discovered in synoptic surveys. Very recently (September 2012), a SN impostor discovered in 2009 (SN 2009ip) was observed to transition to a real SN explosion \citeSmith12. This discovery highlights the importance of studying \eta Car’s GE in great detail.

National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360

 NOAO >   Observing Info >   Approved Programs >   2013A-0349