VERY EARLY ULTRAVIOLET AND OPTICAL OBSERVATIONS OF THE TYPE Ia SUPERNOVA 2009ig

Supernova (SN) 2009ig was discovered 17 hr after explosion by the Lick Observatory Supernova Search, promptly classified as a normal Type Ia SN (SN Ia), peaked at V = 13.5 mag, and was equatorial, making it one of the foremost SNe for intensive study in the last decade. Here, we present ultraviolet (UV) and optical observations of SN 2009ig, starting about 1 day after explosion until around maximum brightness. Our data include excellent UV and optical light curves, 25 premaximum optical spectra, and 8 UV spectra, including the earliest UV spectrum ever obtained of an SN Ia. SN 2009ig is a relatively normal SN Ia, but does display high-velocity ejecta—the ejecta velocity measured in our earliest spectra (v ≈ −23, 000 km s−1 for Si ii λ6355) is the highest yet measured in an SN Ia. The spectral evolution is very dramatic at times earlier than 12 days before maximum brightness, but slows after that time. The early-time data provide a precise measurement of 17.13 ± 0.07 days for the SN rise time. The optical color curves and early-time spectra are significantly different from template light curves and spectra used for light-curve fitting and K-corrections, indicating that the template light curves and spectra do not properly represent all SNe Ia at very early times. In the age of wide-angle sky surveys, SNe like SN 2009ig that are nearby, bright, well positioned, and promptly discovered will still be rare. As shown with SN 2009ig, detailed studies of single events can provide significantly more information for testing systematic uncertainties related to SN Ia distance estimates and constraining progenitor and explosion models than large samples of more distant SNe.

[1]  Robert P. Kirshner,et al.  VELOCITY EVOLUTION AND THE INTRINSIC COLOR OF TYPE Ia SUPERNOVAE , 2011, 1107.3555.

[2]  A. Filippenko,et al.  The rise-time distribution of nearby Type Ia supernovae , 2011, 1107.2404.

[3]  I. Hook,et al.  CONSTRAINING TYPE Ia SUPERNOVAE PROGENITORS FROM THREE YEARS OF SUPERNOVA LEGACY SURVEY DATA , 2011, 1106.4008.

[4]  Robert A. Fesen,et al.  A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA , 2011, 1103.1671.

[5]  Gautham Narayan,et al.  TYPE Ia SUPERNOVA LIGHT CURVE INFERENCE: HIERARCHICAL MODELS IN THE OPTICAL AND NEAR-INFRARED , 2010, 1011.5910.

[6]  Daniel Kasen,et al.  MEASURING EJECTA VELOCITY IMPROVES TYPE Ia SUPERNOVA DISTANCES , 2010, 1011.4517.

[7]  D. Howell,et al.  Type Ia supernovae as stellar endpoints and cosmological tools. , 2010, Nature communications.

[8]  Mansi M. Kasliwal,et al.  HUBBLE SPACE TELESCOPE STUDIES OF NEARBY TYPE Ia SUPERNOVAE: THE MEAN MAXIMUM LIGHT ULTRAVIOLET SPECTRUM AND ITS DISPERSION , 2010, 1010.2211.

[9]  T. Pritchard,et al.  RESULTS OF THE LICK OBSERVATORY SUPERNOVA SEARCH FOLLOW-UP PHOTOMETRY PROGRAM: BVRI LIGHT CURVES OF 165 TYPE Ia SUPERNOVAE , 2010 .

[10]  Robert C. Nichol,et al.  SINGLE OR DOUBLE DEGENERATE PROGENITORS? SEARCHING FOR SHOCK EMISSION IN THE SDSS-II TYPE Ia SUPERNOVAE , 2010, 1008.4797.

[11]  M. Phillips,et al.  NEAR-ULTRAVIOLET PROPERTIES OF A LARGE SAMPLE OF TYPE Ia SUPERNOVAE AS OBSERVED WITH THE Swift UVOT , 2010, 1007.5279.

[12]  D. Berk,et al.  THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET , 2010, 1007.4842.

[13]  M. S. Burns,et al.  SPECTRA AND HUBBLE SPACE TELESCOPE LIGHT CURVES OF SIX TYPE Ia SUPERNOVAE AT 0.511 < z < 1.12 AND THE UNION2 COMPILATION , 2010, 1004.1711.

[14]  R. Nichol,et al.  THE RISE AND FALL OF TYPE Ia SUPERNOVA LIGHT CURVES IN THE SDSS-II SUPERNOVA SURVEY , 2010, 1001.3428.

[15]  R. Kirshner,et al.  SN 2006bt: A PERPLEXING, TROUBLESOME, AND POSSIBLY MISLEADING TYPE Ia SUPERNOVA , 2009, 0912.0263.

[16]  Daniel Kasen,et al.  SEEING THE COLLISION OF A SUPERNOVA WITH ITS COMPANION STAR , 2009, 0909.0275.

[17]  J. Vanderplas,et al.  FIRST-YEAR SLOAN DIGITAL SKY SURVEY-II SUPERNOVA RESULTS: HUBBLE DIAGRAM AND COSMOLOGICAL PARAMETERS , 2009, 0908.4274.

[18]  S. Cenko,et al.  Supernova 2009ig in NGC 1015 , 2009 .

[19]  R. Foley,et al.  IMPROVED DISTANCES TO TYPE Ia SUPERNOVAE WITH TWO SPECTROSCOPIC SUBCLASSES , 2009, 0906.1616.

[20]  L. Zampieri,et al.  ULTRAVIOLET SPECTROSCOPY OF SUPERNOVAE: THE FIRST TWO YEARS OF SWIFT OBSERVATIONS , 2009, 0906.0367.

[21]  Kevin Krisciunas,et al.  THE CARNEGIE SUPERNOVA PROJECT: ANALYSIS OF THE FIRST SAMPLE OF LOW-REDSHIFT TYPE-Ia SUPERNOVAE , 2009, 0910.3317.

[22]  W. M. Wood-Vasey,et al.  SN 2008ha: AN EXTREMELY LOW LUMINOSITY AND EXCEPTIONALLY LOW ENERGY SUPERNOVA , 2009, 0902.2794.

[23]  Armin Rest,et al.  IMPROVED DARK ENERGY CONSTRAINTS FROM ∼100 NEW CfA SUPERNOVA TYPE Ia LIGHT CURVES , 2009, 0901.4804.

[24]  Caltech,et al.  THE GOLDEN STANDARD TYPE Ia SUPERNOVA 2005cf: OBSERVATIONS FROM THE ULTRAVIOLET TO THE NEAR-INFRARED WAVEBANDS , 2008, 0811.1205.

[25]  T. Matheson,et al.  A SECOND CASE OF VARIABLE Na i D LINES IN A HIGHLY REDDENED TYPE Ia SUPERNOVA , 2008, 0811.0002.

[26]  R. Kotak,et al.  Optical and infrared observations of SN 2002dj: some possible common properties of fast‐expanding Type Ia supernovae , 2008, 0805.1089.

[27]  S. Jha,et al.  Luminosity Indicators in the Ultraviolet Spectra of Type Ia Supernovae , 2008, 0803.1181.

[28]  R. Kirshner,et al.  Properties of the ultraviolet flux of Type Ia supernovae : an analysis with synthetic spectra of SN 2001ep and SN 2001eh , 2008, 0803.0871.

[29]  M. J. Page,et al.  Photometric calibration of the Swift ultraviolet/optical telescope , 2007, 0708.2259.

[30]  M. Strovink.  Diversity of Decline Rate-corrected Type Ia Supernova Rise Times: One Mode or Two? , 2007, 0705.0726.

[31]  Niall Gaffney,et al.  Ten Year Review of Queue Scheduling of the Hobby‐Eberly Telescope , 2007, 0705.3889.

[32]  M. Sullivan,et al.  K-Corrections and Spectral Templates of Type Ia Supernovae , 2007, astro-ph/0703529.

[33]  W. M. Wood-Vasey,et al.  Observational Constraints on the Nature of Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey , 2007, astro-ph/0701041.

[34]  Mohan Ganeshalingam,et al.  SN 2006jc: A Wolf-Rayet Star Exploding in a Dense He-rich Circumstellar Medium , 2006, astro-ph/0612711.

[35]  A. Riess,et al.  Improved Distances to Type Ia Supernovae with Multicolor Light-Curve Shapes: MLCS2k2 , 2006, astro-ph/0612666.

[36]  Stefano Casertano,et al.  New Hubble Space Telescope Discoveries of Type Ia Supernovae at z ≥ 1: Narrowing Constraints on the Early Behavior of Dark Energy , 2006, astro-ph/0611572.

[37]  J. Neill,et al.  The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star , 2006, Nature.

[38]  F. Stootman,et al.  The Northern HIPASS catalogue - data presentation, completeness and reliability measures , 2006, astro-ph/0607491.

[39]  J. Neill,et al.  The Rise Time of Type Ia Supernovae from the Supernova Legacy Survey , 2006, astro-ph/0607363.

[40]  J. Bloom,et al.  The Calibration of the Swift UVOT Optical Observations: A Recipe for Photometry , 2005, astro-ph/0505504.

[41]  Warren R. Brown,et al.  UBVRI Light Curves of 44 Type Ia Supernovae , 2005, astro-ph/0509234.

[42]  Nicholas B. Suntzeff,et al.  An Atlas of Spectrophotometric Landolt Standard Stars , 2005, astro-ph/0504244.

[43]  Alan A. Wells,et al.  The Swift Gamma-Ray Burst Mission , 2004, astro-ph/0405233.

[44]  Peter W. A. Roming,et al.  The Swift Ultra-Violet/Optical Telescope , 2002, SPIE Optics + Photonics.

[45]  R. Foley,et al.  Optical Photometry and Spectroscopy of the SN 1998bw–like Type Ic Supernova 2002ap , 2003, astro-ph/0307136.

[46]  S. E. Persson,et al.  An asymptotic-giant-branch star in the progenitor system of a type Ia supernova , 2003, Nature.

[47]  Alison L. Coil,et al.  The DEIMOS spectrograph for the Keck II Telescope: integration and testing , 2003, SPIE Astronomical Telescopes + Instrumentation.

[48]  Caltech,et al.  SN 2002cx: The Most Peculiar Known Type Ia Supernova , 2003, astro-ph/0301428.

[49]  A. Moorwood,et al.  Instrument Design and Performance for Optical/Infrared Ground-based Telescopes, , 2003 .

[50]  P. Nugent,et al.  K‐Corrections and Extinction Corrections for Type Ia Supernovae , 2002, astro-ph/0205351.

[51]  E. Ofek,et al.  The Unique Type Ia Supernova 2000cx in NGC 524 , 2001, astro-ph/0107318.

[52]  D. Branch,et al.  Non-LTE Synthetic Spectral Fits to the Type Ia Supernova 1994D in NGC 4526 , 2001, astro-ph/0104225.

[53]  W. Hillebrandt,et al.  Type IA Supernova Explosion Models , 2000, astro-ph/0006305.

[54]  L. Ho,et al.  Optical Spectroscopy of Supernova 1993J During Its First 2500 Days , 2000, astro-ph/0006263.

[55]  C. Alard.  Image subtraction using a space-varying kernel , 2000 .

[56]  P. Nugent,et al.  The Rise Times of High- and Low-Redshift Type Ia Supernovae Are Consistent , 2000, astro-ph/0001049.

[57]  I. Hook,et al.  Measurements of Ω and Λ from 42 High-Redshift Supernovae , 1998, astro-ph/9812133.

[58]  Phillip J. MacQueen,et al.  Hobby-Eberly Telescope low-resolution spectrograph , 1998, Astronomical Telescopes and Instrumentation.

[59]  D. Schlegel,et al.  Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds , 1998 .

[60]  A. Riess,et al.  Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant , 1998, astro-ph/9805201.

[61]  J. Wheeler,et al.  Type Ia Supernovae: Influence of the Initial Composition on the Nucleosynthesis, Light Curves, and Spectra and Consequences for the Determination of ΩM and Λ , 1997, astro-ph/9709233.

[62]  D. Schlegel,et al.  Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds , 1997, astro-ph/9710327.

[63]  Harland W. Epps,et al.  THE KECK LOW-RESOLUTION IMAGING SPECTROMETER , 1995 .

[64]  Claudia Winge,et al.  SN 1992A : ultraviolet and optical studies based on HST, IUE and CTIO observations , 1993 .

[65]  R. Kirshner,et al.  Analysis of the photospheric epoch spectra of type 1a supernovae SN 1990N and SN 1991T , 1992 .

[66]  Arlo U. Landolt,et al.  UBVRI Photometric Standard Stars in the Magnitude Range 11 , 1992 .

[67]  R. Kirshner,et al.  Premaximum observations of the type Ia SN 1990N , 1991 .

[68]  R. Weymann,et al.  A MODERATE-RESOLUTION, HIGH-THROUGHPUT CCD CHANNEL FOR THE MMT SPECTROGRAPH , 1989 .

[69]  R. Tully.  Nearby Galaxies Catalog , 1988 .

[70]  R. Wade,et al.  The Radial Velocity Curve and Peculiar TiO Distribution of the Red Secondary Star in Z Chamaeleontis , 1988 .

[71]  D. Branch,et al.  On the ultraviolet spectra of Type I supernovae , 1986 .

[72]  K. Horne,et al.  AN OPTIMAL EXTRACTION ALGORITHM FOR CCD SPECTROSCOPY. , 1986 .

[73]  S. Woosley,et al.  Models for Type I Supernova. I. Detonations in White Dwarfs , 1986 .

[74]  A. V. Filippenko,et al.  THE IMPORTANCE OF ATMOSPHERIC DIFFERENTIAL REFRACTION IN SPECTROPHOTOMETRY. , 1982 .

[75]  W. Arnett.  Type I supernovae. I. Analytic solutions for the early part of the light curve , 1982 .

[76]  S. Colgate,et al.  EARLY SUPERNOVA LUMINOSITY. , 1969 .

[77]  William A. Fowler,et al.  Nucleosynthesis in Supernovae. , 1960 .