With the advent of new wide-field, high-cadence optical transient surveys, our understanding of the diversity of core-collapse supernovae has grown tremendously in the last decade. However, the pre-supernova evolution of massive stars, which sets the physical backdrop to these violent events, is theoretically not well understood and difficult to probe observationally. Here we report the discovery of the supernova iPTF 13dqy  = SN 2013fs  a mere 3 h after explosion. Our rapid follow-up observations, which include multiwavelength photometry and extremely early (beginning at 6 h post-explosion) spectra, map the distribution of material in the immediate environment (1015 cm) of the exploding star and establish that it was surrounded by circumstellar material (CSM) that was ejected during the final 1 yr prior to explosion at a high rate, around 10−3 solar masses per year. The complete disappearance of flash-ionized emission lines within the first several days requires that the dense CSM be confined to within 1015 cm, consistent with radio non-detections at 70–100 days. The observations indicate that iPTF 13dqy was a regular type II supernova; thus, the finding that the probable red supergiant progenitor of this common explosion ejected material at a highly elevated rate just prior to its demise suggests that pre-supernova instabilities may be common among exploding massive stars.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    Presupernova evolution of massive single and binary stars. Annu. Rev. Astron. Astrophys. 50, 107–164 (2012).

  2. 2.

    et al. A Wolf–Rayet-like progenitor of SN 2013cu from spectral observations of a stellar wind. Nature 509, 471–474 (2014).

  3. 3.

    et al. Precursors prior to type IIn supernova explosions are common: precursor rates, properties, and correlations. Astrophys. J. 789, 104 (2014).

  4. 4.

    et al. The unprecedented 2012 outburst of SN 2009ip: a luminous blue variable star becomes a true supernova. Mon. Not. R. Astron. Soc. 430, 1801–1810 (2013).

  5. 5.

    et al. Massive stars exploding in a He-rich circumstellar medium - I. Type Ibn (SN 2006jc-like) events. Mon. Not. R. Astron. Soc. 389, 113–130 (2008).

  6. 6.

    & The remarkable deaths of 9–11 solar Mass stars. Astrophys. J. 810, 34 (2015).

  7. 7.

    & Setting the stage for circumstellar interaction in core-collapse supernovae. II. Wave-driven mass loss in supernova progenitors. Astrophys. J. 780, 96 (2014).

  8. 8.

    & Toward realistic progenitors of core-collapse supernovae. Astrophys. J. 733, 78 (2011).

  9. 9.

    & Evolution of massive stars with pulsation-driven superwinds during the red supergiant phase. Astrophys. J. Lett. 717, L62–L65 (2010).

  10. 10.

    et al. Flash spectroscopy: emission lines from the ionized circumstellar material around <10-day-old type II supernovae. Astrophys. J. 818, 3 (2016).

  11. 11.

    , , & Observed fractions of core-collapse supernova types and initial masses of their single and binary progenitor stars. Mon. Not. R. Astron. Soc. 412, 1522–1538 (2011).

  12. 12.

    et al. Circumstellar medium around rotating massive stars at solar metallicity. Astron. Astrophys. 559, A69 (2013).

  13. 13.

    , , & The circumstellar environment of Wolf-Rayet stars and gamma-ray burst afterglows. Mon. Not. R. Astron. Soc. 367, 186–200 (2006).

  14. 14.

    et al. The Palomar Transient Factory: system overview, performance, and first results. Publ. Astron. Soc. Pac. 121, 1395–1408 (2009).

  15. 15.

    et al. Supernova 2013fs in NGC 7610 = Psn J23194467+1011045. Cent. Bur. Electron. Telegr. 3671, 1 (2013).

  16. 16.

    et al. Early emission from the type IIn supernova 1998S at high resolution. Astrophys. J. 806, 213 (2015).

  17. 17.

    et al. Toward a cosmological Hubble diagram for type II-P supernovae. Astrophys. J. 645, 841–850 (2006).

  18. 18.

    et al. Photometric and spectroscopic properties of type II-P supernovae. Mon. Not. R. Astron. Soc. 442, 844–861 (2014).

  19. 19.

    et al. Optical and near-infrared coverage of SN 2004et: physical parameters and comparison with other type IIP supernovae. Mon. Not. R. Astron. Soc. 404, 981–1004 (2010).

  20. 20.

    Early-time spectra of supernovae and their precursor winds. The luminous blue variable/yellow hypergiant progenitor of SN 2013cu. Astron. Astrophys. 572, L11 (2014).

  21. 21.

    , & Radio and X-ray emission as probes of type IIP supernovae and red supergiant mass loss. Astrophys. J. 641, 1029–1038 (2006).

  22. 22.

    The Chemistry of Dust Formation in Red Supergiants (eds Kervella, P., Le Bertre, T. & Perrin, G.) Vol. 60, 175–184 (EAS Publications Series, 2013).

  23. 23.

    et al. Caltech core-collapse project (CCCP) observations of type IIn supernovae: typical properties and implications for their progenitor stars. Astrophys. J. 744, 10 (2012).

  24. 24.

    & The early UV/optical emission from core-collapse supernovae. Astrophys. J. 728, 63 (2011).

  25. 25.

    et al. Type II supernova energetics and comparison of light curves to shock-cooling models. Astrophys. J. 820, 33 (2016).

  26. 26.

    , , & Type II-plateau supernova radiation: dependences on progenitor and explosion properties. Mon. Not. R. Astron. Soc. 433, 1745–1763 (2013).

  27. 27.

    et al. Light curves of core-collapse supernovae with substantial mass loss using the new open-source supernova explosion code (SNEC). Astrophys. J. 814, 63 (2015).

  28. 28.

    et al. Interacting supernovae from photoionization-confined shells around red supergiant stars. Nature 512, 282–285 (2014).

  29. 29.

    Broad emission lines from the opaque electron-scattering environment of SN 1998S. Mon. Not. R. Astron. Soc. 326, 1448–1454 (2001).

  30. 30.

    et al. An outburst from a massive star 40 days before a supernova explosion. Nature 494, 65–67 (2013).

  31. 31.

    et al. PTF11iqb: cool supergiant mass-loss that bridges the gap between type IIn and normal supernovae. Mon. Not. R. Astron. Soc. 449, 1876–1896 (2015).

  32. 32.

    & WISeREP—an interactive supernova data repository. Publ. Astron. Soc. Pac. 124, 668–681 (2012).

  33. 33.

    et al. Exploring the optical transient sky with the Palomar Transient Factory. Publ. Astron. Soc. Pac. 121, 1334–1351 (2009).

  34. 34.

    & The treatment of non-LTE line blanketing in spherically expanding outflows. Astrophys. J. 496, 407–427 (1998).

  35. 35.

    The intermediate Palomar Transient Factory (iPTF) begins. Astron. Telegr. 4807, 1 (2013).

  36. 36.

    et al. The 12K × 8K CCD Mosaic Camera for the Palomar Transient Factory Vol. 7014 (Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, 4, 2008).

  37. 37.

    et al. IPAC image processing and data archiving for the Palomar Transient Factory. Publ. Astron. Soc. Pac. 126, 674–710 (2014).

  38. 38.

    et al. The Palomar Transient Factory photometric calibration. Publ. Astron. Soc. Pac. 124, 62–73 (2012).

  39. 39.

    et al. The Palomar Transient Factory photometric catalog 1.0. Publ. Astron. Soc. Pac. 124, 854–860 (2012).

  40. 40.

    et al. Using machine learning for discovery in synoptic survey imaging data. Mon. Not. R. Astron. Soc. 435, 1047–1060 (2013).

  41. 41.

    et al. Automated Variability Selection in Time-domain Imaging Surveys Using Sparse Representations with Learned Dictionaries Vol. 221 (American Astronomical Society Meeting Abstracts, 431.05, 2013).

  42. 42.

    , & Time-Domain Surveys and Data Shift: Case Study at the Intermediate Palomar Transient Factory Vol. 225 (American Astronomical Society Meeting Abstracts, 434.02, 2015).

  43. 43.

    et al. Real-time detection and rapid multiwavelength follow-up observations of a highly subluminous type II-P supernova from the Palomar Transient Factory survey. Astrophys. J. 736, 159 (2011).

  44. 44.

    et al. The automated Palomar 60 inch telescope. Publ. Astron. Soc. Pac. 118, 1396–1406 (2006).

  45. 45.

    , & The relationship between infrared, optical, and ultraviolet extinction. Astrophys. J. 345, 245–256 (1989).

  46. 46.

    & K-corrections and filter transformations in the ultraviolet, optical, and near-infrared. Astron. J. 133, 734–754 (2007).

  47. 47.

    , , & The UKIRT infrared deep sky survey ZY JHK photometric system: passbands and synthetic colours. Mon. Not. R. Astron. Soc. 367, 454–468 (2006).

  48. 48.

    et al. The Swift gamma-ray burst mission. Astrophys. J. 611, 1005–1020 (2004).

  49. 49.

    et al. SN 2010jl: optical to hard X-ray observations reveal an explosion embedded in a ten solar mass cocoon. Astrophys. J. 781, 42 (2014).

  50. 50.

    et al. The Keck low-resolution imaging spectrometer. Publ. Astron. Soc. Pac. 107, 375–385 (1995).

  51. 51.

    & An efficient low resolution and moderate resolution spectrograph for the Hale telescope. Publ. Astron. Soc. Pac. 94, 586–594 (1982).

  52. 52.

    et al. The DEIMOS Spectrograph for the Keck II Telescope: Integration and Testing (eds Iye, M. & Moorwood, A. F. M.) Vol. 4841, 1657–1669 (Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, 2003).

  53. 53.

    & The Kast Double Spectograph Lick Observatory Technical Reports (University of California Observatories/Lick Observatory, 1994);

  54. 54.

    et al. SN 2009ip: constraints on the progenitor mass-loss rate. Astrophys. J. 768, 47 (2013).

  55. 55.

    & Astrophysics of Gaseous Nebulae and Active Galactic Nuclei (University Science Books, 2006).

  56. 56.

    et al. High-density Circumstellar interaction in the luminous type IIn SN 2010jl: the first 1100 days. Astrophys. J. 797, 118 (2014).

  57. 57.

    , , & Fundamental properties of core-collapse supernova and GRB progenitors: predicting the look of massive stars before death. Astron. Astrophys. 558, A131 (2013).

  58. 58.

    , , & Pulsations in red supergiants with high L/M ratio. Implications for the stellar and circumstellar structure of supernova progenitors. Astron. Astrophys. 327, 224–230 (1997).

  59. 59.

    The radio and X-ray emission from type II supernovae. Astrophys. J. 259, 302–310 (1982).

  60. 60.

    Synchrotron self-absorption in radio supernovae. Astrophys. J. 499, 810–819 (1998).

  61. 61.

    & Circumstellar emission from type Ib and Ic supernovae. Astrophys. J. 651, 381–391 (2006).

  62. 62.

    , , & Radio emission from supernovae and gamma-ray bursters. Annu. Rev. Astron. Astrophys. 40, 387–438 (2002).

  63. 63.

    AIPS, the VLA, and the VLBA. Inf. Hand. Astron. 285, 109–125 (2003).

  64. 64.

    & Radio emission and particle acceleration in SN 1993J. Astrophys. J. 509, 861–878 (1998).

Download references


We are grateful to the staff at the various observatories where data were obtained, as well as to N. E. Groeneboom, K. I. Clubb, M. L. Graham, D. Sand, A. A. Djupvik, I. Shivvers, J. C. Mauerhan and A. Waszczak for assistance with observations. We thank E. Waxman for valuable discussions. A.G.-Y.’s group is supported by the EU/FP7 via an ERC grant, the Quantum Universe I-Core programme by the Israeli Committee for planning and budgeting and the ISF; by Minerva and ISF grants; by the Weizmann-UK ‘making connections’ programme; and by Kimmel, ARCHES and Yes awards. D.A.P. acknowledges support from Hubble Fellowship grant HST-HF-51296.01-A awarded by the Space Telescope Science Institute, and from a Marie Curie Individual Fellowship as part of the Horizon 2020 European Union (EU) Framework Programme for Research and Innovation (H2020-MSCA-IF-2014-660113). J.H.G. acknowledges support from an AMBIZIONE grant of the Swiss NSF. E.O.O. is supported by the Arye Dissentshik career development chair, Israel Science Foundation, Minerva, Weizmann-UK, and the I-Core programme. M.M.K. acknowledges support from the National Science Foundation for the GROWTH project funded under Grant No. 1545949. A.V.F.’s research is supported by the Christopher R. Redlich Fund, the TABASGO Foundation, and US NSF grant AST-1211916. Support for I.A. was provided by NASA through the Einstein Fellowship Program, grant PF6-170148. LANL participation in iPTF is supported by the US Department of Energy as part of the Laboratory Directed Research and Development programme. Supernova research at the Oskar Klein Centre is supported by the Swedish Research Council and by the Knut and Alice Wallenberg Foundation. K.M. acknowledges support from a Marie Curie Intra-European Fellowship, within the 7th European Community Framework Programme (FP7). Some data were obtained with the Nordic Optical Telescope, which is operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain. We thank the RATIR project team, the staff of the Observatorio Astronomico Nacional on Sierra San Pedro Martir, and the software support team from Teledyne Scientific and Imaging. RATIR, the automation of the Harold L. Johnson Telescope of the Observatorio Astronomico Nacional and the operation of both are funded through National Aeronautics and Space Administration (NASA) grants NNX09AH71G, NNX09AT02G, NNX10AI27G and NNX12AE66G, CONACyT (INFR-2009-01-122785, CB-2008-101958), UNAM PAPIIT (IN113810 and IG100414) and UCMEXUS-CONACyT. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Research at Lick Observatory is partially supported by a generous gift from Google. A portion of this work was carried out at the Jet Propulsion Laboratory under a Research and Technology Development Grant, under contract with NASA.

Author information


  1. Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100, Israel

    • O. Yaron
    • , A. Gal-Yam
    • , E. O. Ofek
    • , A. Rubin
    • , P. Szabo
    • , N. Sapir
    • , P. M. Vreeswijk
    • , D. Khazov
    •  & M. T. Soumagnac
  2. Division of Physics, Math and Astronomy, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California 91125, USA

    • D. A. Perley
    • , S. R. Kulkarni
    • , M. M. Kasliwal
    •  & Y. Cao
  3. Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark

    • D. A. Perley
  4. School of Physics, Trinity College Dublin, Dublin 2, Ireland

    • J. H. Groh
  5. Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel

    • A. Horesh
    •  & O. Gnat
  6. The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm, Sweden

    • J. Sollerman
    • , C. Fransson
    •  & F. Taddia
  7. Plasma Physics Department, Soreq Nuclear Research Center, Yavne 81800, Israel

    • N. Sapir
  8. Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, Maryland 20771, USA

    • S. B. Cenko
  9. Joint Space-Science Institute, University of Maryland, College Park, Maryland 20742, USA

    • S. B. Cenko
  10. Department of Physics, University of California, 1 Shields Avenue, Davis, California 95616-5270, USA

    • S. Valenti
  11. Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Goleta, California 93117, USA

    • I. Arcavi
    •  & D. A. Howell
  12. Department of Physics, University of California, Santa Barbara, California 93106-9530, USA

    • I. Arcavi
    •  & D. A. Howell
  13. Department of Astronomy, University of California, Berkeley, California 94720-3411, USA

    • O. D. Fox
    • , P. L. Kelly
    • , P. E. Nugent
    •  & A. V. Filippenko
  14. Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, California 94720, USA

    • P. E. Nugent
  15. Spitzer Science Center, California Institute of Technology, Pasadena, California 91125, USA

    • R. R. Laher
  16. Los Alamos National Laboratory, Mail Stop B244, Los Alamos, New Mexico 87545, USA

    • P. R. Wozniak
  17. Instituto de Astronomía, Universidad Nacional Autonóma de México, Apdo. Postal 70-264, 04510 México DF, México

    • W. H. Lee
  18. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA

    • U. D. Rebbapragada
  19. Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, UK

    • K. Maguire
  20. School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK

    • M. Sullivan


  1. Search for O. Yaron in:

  2. Search for D. A. Perley in:

  3. Search for A. Gal-Yam in:

  4. Search for J. H. Groh in:

  5. Search for A. Horesh in:

  6. Search for E. O. Ofek in:

  7. Search for S. R. Kulkarni in:

  8. Search for J. Sollerman in:

  9. Search for C. Fransson in:

  10. Search for A. Rubin in:

  11. Search for P. Szabo in:

  12. Search for N. Sapir in:

  13. Search for F. Taddia in:

  14. Search for S. B. Cenko in:

  15. Search for S. Valenti in:

  16. Search for I. Arcavi in:

  17. Search for D. A. Howell in:

  18. Search for M. M. Kasliwal in:

  19. Search for P. M. Vreeswijk in:

  20. Search for D. Khazov in:

  21. Search for O. D. Fox in:

  22. Search for Y. Cao in:

  23. Search for O. Gnat in:

  24. Search for P. L. Kelly in:

  25. Search for P. E. Nugent in:

  26. Search for A. V. Filippenko in:

  27. Search for R. R. Laher in:

  28. Search for P. R. Wozniak in:

  29. Search for W. H. Lee in:

  30. Search for U. D. Rebbapragada in:

  31. Search for K. Maguire in:

  32. Search for M. Sullivan in:

  33. Search for M. T. Soumagnac in:


O.Y. initiated the study, conducted analysis and wrote the manuscript. D.A.P. is PI of the first-night Keck programme, obtained and reduced the Keck/LRIS spectra, and contributed to the analysis of the early-time data. A.G.-Y. is PI of iPTF early-time SN II studies, managed the project, and contributed to analysis and manuscript preparation. J.H.G. performed modelling and analysis of the early spectra. A.H. is PI of the VLA radio programme, provided radio observations, reduction, and analysis, and contributed to figures and manuscript preparation. E.O.O. contributed to analysis of early-time data, mass-loss estimates, Swift-XRT reductions and manuscript preparation. S.R.K. is PI of PTF and of Palomar and Keck follow-up programmes. J.S. provided NOT spectroscopy and contributed to analysis and manuscript preparation. C.F. contributed to analysis of line profiles, estimates of physical properties, and X-ray and radio data interpretation. A.R. performed analysis of the multiband photometry fits to RW11 shock-cooling models. P.S. performed SBO models and contributed to analysis of X-ray emission. N.S. contributed to analysis of SBO properties, early-time spectral modelling, and X-ray emission. F.T. provided and reduced NOT data. S.B.C. reduced Swift and Palomar 60-inch data, and contributed to spectroscopic reduction and analysis. S.V. provided LCOGT multiband photometry and reduced FTS-FLOYDS spectroscopy. I.A. provided LCOGT multiband photometry and reduced FTS-FLOYDS spectroscopy. D.A.H. is PI of the LCOGT follow-up programme. M.M.K. is a PTF builder and provided APO data. P.M.V. contributed to spectroscopic reductions, analysis and figure preparation. D.K. contributed to analysis of the early flash-ionized spectra and to figure preparation. O.D.F. provided RATIR multiband photometry. Y.C. is a PTF builder and performed spectroscopic observations and reductions. O.G. contributed to radiative-transfer analysis of the early-time emission-line spectra. P.L.K. contributed to Keck-II/DEIMOS spectroscopic reductions. P.E.N. is a PTF builder and contributed to manuscript preparation. A.V.F. provided Keck and Lick data, and edited the manuscript. R.R.L. is a developer of the image reduction pipeline. P.R.W. is a PTF builder, involved with machine-learning development. W.H.L. is PI of the RATIR proposals. U.D.R. is a PTF builder, involved with machine-learning development. K.M. is PI of the WHT ToO spectroscopic time, and performed WHT-ISIS spectroscopic reductions. M.S. is PI of the WHT follow-up effort. M.T.S. is a member of the iPTF human monitoring (scanners) team.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to O. Yaron.

Supplementary information

PDF files

  1. 1.

    Supplementary information

    Supplementary information

About this article

Publication history






Further reading

  • A surge of light at the birth of a supernova

    • M. C. Bersten
    • , G. Folatelli
    • , F. García
    • , S. D. Van Dyk
    • , O. G. Benvenuto
    • , M. Orellana
    • , V. Buso
    • , J. L. Sánchez
    • , M. Tanaka
    • , K. Maeda
    • , A. V. Filippenko
    • , W. Zheng
    • , T. G. Brink
    • , S. B. Cenko
    • , T. de Jaeger
    • , S. Kumar
    • , T. J. Moriya
    • , K. Nomoto
    • , D. A. Perley
    • , I. Shivvers
    •  & N. Smith

    Nature (2018)

  • The delay of shock breakout due to circumstellar material evident in most type II supernovae

    • F. Förster
    • , T. J. Moriya
    • , J. C. Maureira
    • , J. P. Anderson
    • , S. Blinnikov
    • , F. Bufano
    • , G. Cabrera-Vives
    • , A. Clocchiatti
    • , T. de Jaeger
    • , P. A. Estévez
    • , L. Galbany
    • , S. González-Gaitán
    • , G. Gräfener
    • , M. Hamuy
    • , E. Y. Hsiao
    • , P. Huentelemu
    • , P. Huijse
    • , H. Kuncarayakti
    • , J. Martínez
    • , G. Medina
    • , F. Olivares E.
    • , G. Pignata
    • , A. Razza
    • , I. Reyes
    • , J. San Martín
    • , R. C. Smith
    • , E. Vera
    • , A. K. Vivas
    • , A. de Ugarte Postigo
    • , S.-C. Yoon
    • , C. Ashall
    • , M. Fraser
    • , A. Gal-Yam
    • , E. Kankare
    • , L. Le Guillou
    • , P. A. Mazzali
    • , N. A. Walton
    •  & D. R. Young

    Nature Astronomy (2018)

  • Neutrinos from Supernovae

    • Irene Tamborra
    •  & Kohta Murase

    Space Science Reviews (2018)

  • Peculiar Supernovae

    • Dan Milisavljevic
    •  & Raffaella Margutti

    Space Science Reviews (2018)

  • Memories of a dying star

    • Norbert Langer

    Nature Physics (2017)