skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip

Abstract

We present progenitor-star detections, light curves, and optical spectra of supernova (SN) 2009ip and the 2009 optical transient in UGC 2773 (U2773-OT), which were not genuine SNe. Precursor variability in the decade before outburst indicates that both of the progenitor stars were luminous blue variables (LBVs). Their pre-outburst light curves resemble the S Doradus phases that preceded giant eruptions of the prototypical LBVs {eta} Carinae and SN 1954J (V12 in NGC 2403), with intermediate progenitor luminosities. Hubble Space Telescope detections a decade before discovery indicate that the SN 2009ip and U2773-OT progenitors were supergiants with likely initial masses of 50-80 M {sub sun} and {approx}>20 M {sub sun}, respectively. Both outbursts had spectra befitting known LBVs, although in different physical states. SN 2009ip exhibited a hot LBV spectrum with characteristic speeds of 550 km s{sup -1}, plus evidence for faster material up to 5000 km s{sup -1}, resembling the slow Homunculus and fast blast wave of {eta} Carinae. In contrast, U2773-OT shows a forest of narrow absorption and emission lines comparable to that of S Dor in its cool state, plus [Ca II] emission and an infrared excess indicative of dust, similar to SN 2008S and the 2008 optical transientmore » in NGC 300 (N300-OT). The [Ca II] emission is probably tied to a dusty pre-outburst environment, and is not a distinguishing property of the outburst mechanism. The LBV nature of SN 2009ip and U2773-OT may provide a critical link between historical LBV eruptions, while U2773-OT may provide a link between LBVs and the unusual dust-obscured transients SN 2008S and N300-OT. Future searches will uncover more examples of precursor LBV variability of this kind, providing key clues that may help unravel the instability driving LBV eruptions in massive stars.« less

Authors:
; ; ; ; ; ; ;  [1];  [2]; ; ;  [3]; ;  [4]
  1. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
  2. Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 (United States)
  3. Division of Astronomy and Astrophysics, University of California, Los Angeles, CA 90095-1547 (United States)
  4. Department of Astronomy and Astrophysics, 1156 High Street, UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States), E-mail: nathans@astro.berkeley.edu
Publication Date:
OSTI Identifier:
21301212
Resource Type:
Journal Article
Journal Name:
Astronomical Journal (New York, N.Y. Online)
Additional Journal Information:
Journal Volume: 139; Journal Issue: 4; Other Information: DOI: 10.1088/0004-6256/139/4/1451; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-3881
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ABSORPTION; DUSTS; ERUPTION; LUMINOSITY; MASS; MATTER; SPECTRA; STAR EVOLUTION; SUPERNOVAE; TELESCOPES; TRANSIENTS

Citation Formats

Smith, Nathan, Miller, Adam, Li Weidong, Filippenko, Alexei V., Silverman, Jeffrey M., Howard, Andrew W., Marcy, Geoffrey W., Bloom, Joshua S., Nugent, Peter, Ghez, Andrea M., Lu, Jessica, Yelda, Sylvana, Bernstein, Rebecca A., and Colucci, Janet E. DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip. United States: N. p., 2010. Web. doi:10.1088/0004-6256/139/4/1451; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Smith, Nathan, Miller, Adam, Li Weidong, Filippenko, Alexei V., Silverman, Jeffrey M., Howard, Andrew W., Marcy, Geoffrey W., Bloom, Joshua S., Nugent, Peter, Ghez, Andrea M., Lu, Jessica, Yelda, Sylvana, Bernstein, Rebecca A., & Colucci, Janet E. DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip. United States. doi:10.1088/0004-6256/139/4/1451; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Smith, Nathan, Miller, Adam, Li Weidong, Filippenko, Alexei V., Silverman, Jeffrey M., Howard, Andrew W., Marcy, Geoffrey W., Bloom, Joshua S., Nugent, Peter, Ghez, Andrea M., Lu, Jessica, Yelda, Sylvana, Bernstein, Rebecca A., and Colucci, Janet E. Thu . "DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip". United States. doi:10.1088/0004-6256/139/4/1451; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21301212,
title = {DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip},
author = {Smith, Nathan and Miller, Adam and Li Weidong and Filippenko, Alexei V. and Silverman, Jeffrey M. and Howard, Andrew W. and Marcy, Geoffrey W. and Bloom, Joshua S. and Nugent, Peter and Ghez, Andrea M. and Lu, Jessica and Yelda, Sylvana and Bernstein, Rebecca A. and Colucci, Janet E.},
abstractNote = {We present progenitor-star detections, light curves, and optical spectra of supernova (SN) 2009ip and the 2009 optical transient in UGC 2773 (U2773-OT), which were not genuine SNe. Precursor variability in the decade before outburst indicates that both of the progenitor stars were luminous blue variables (LBVs). Their pre-outburst light curves resemble the S Doradus phases that preceded giant eruptions of the prototypical LBVs {eta} Carinae and SN 1954J (V12 in NGC 2403), with intermediate progenitor luminosities. Hubble Space Telescope detections a decade before discovery indicate that the SN 2009ip and U2773-OT progenitors were supergiants with likely initial masses of 50-80 M {sub sun} and {approx}>20 M {sub sun}, respectively. Both outbursts had spectra befitting known LBVs, although in different physical states. SN 2009ip exhibited a hot LBV spectrum with characteristic speeds of 550 km s{sup -1}, plus evidence for faster material up to 5000 km s{sup -1}, resembling the slow Homunculus and fast blast wave of {eta} Carinae. In contrast, U2773-OT shows a forest of narrow absorption and emission lines comparable to that of S Dor in its cool state, plus [Ca II] emission and an infrared excess indicative of dust, similar to SN 2008S and the 2008 optical transient in NGC 300 (N300-OT). The [Ca II] emission is probably tied to a dusty pre-outburst environment, and is not a distinguishing property of the outburst mechanism. The LBV nature of SN 2009ip and U2773-OT may provide a critical link between historical LBV eruptions, while U2773-OT may provide a link between LBVs and the unusual dust-obscured transients SN 2008S and N300-OT. Future searches will uncover more examples of precursor LBV variability of this kind, providing key clues that may help unravel the instability driving LBV eruptions in massive stars.},
doi = {10.1088/0004-6256/139/4/1451; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 4,
volume = 139,
place = {United States},
year = {2010},
month = {4}
}