Padova-Asiago Supernova Group
Highlights

Optical photometry and spectroscopy of the low-luminosity, broad-lined Ic supernova iPTF15dld
Pian, E. et al. 2017 MNRAS 466, 1848
Core-collapse stripped-envelope supernova (SN) explosions reflect the diversity of physical parameters and evolutionary paths of their massive star progenitors. We have observed the type Ic SN iPTF15dld (z = 0.047), reported by the Palomar Transient Factory. Spectra were taken starting 20 rest-frame days after maximum luminosity and are affected by .......

Radiation-hydrodynamical modelling of underluminous type II plateau Supernovae
Pumo M. L. etw al. 2016 MNRAS in press (arXiv 1610.024002v1)
With the aim of improving our knowledge about the nature of the progenitors of low-luminosity Type II plateau supernovae (LL SNe IIP), we made radiation- hydrodynamical models of the well-sampled LL SNe IIP 2003Z, 2008bk and 2009md. For these three SNe we infer explosion energies of 0.16-0.18 foe, radii at .......

Supernova rates from the SUDARE VST-Omegacam search II. Rates in a galaxy sample.
Botticella, M.T. et al. 2016 A&A in press (arXiv:1610.01176v1)
| Aims. This is the second paper of a series in which we present measurements of the Supernova (SN) rates from the SUDARE survey. The aim of this survey is to constrain the core collapse (CC) and Type Ia SN progenitors by analysing the dependence of their explosion rate on .......

Dead or Alive? Long-time evolution of SN 2015bh (SNhunt275)
Elias-Rosa, N., et al. 2016 MNRAS in press (arXiv:1606.09024)
Supernova (SN) 2015bh (or SNhunt275) was discovered in NGC 2770 on 2015 February with an absolute magnitude of Mr ~ -13 mag, and was initially classified as a SN impostor. Here we present the photometric and spectroscopic evolution of SN 2015bh from discovery to late phases (~ 1 yr after). .......

The multi-faceted Type II-L supernova 2014G from pre-maximum to nebular phase
Terreran, G. et al 2016 MNRAS 462,137
We present multi-band ultraviolet, optical, and near-infrared photometry, along with visual-wavelength spectroscopy, of supernova (SN) 2014G in the nearby galaxy NGC 3448 (25 Mpc). The early-phase spectra show strong emission lines of the high ionisation species He II/N IV/C IV during the first 2-3 d after explosion, traces of a .......

The supernova impostor PSN J09132750+7627410 and its progenitor
Tartaglia, L. et al. 2016 ApJ 823, L23
We report the results of our follow-up campaign of the supernova impostor PSN J09132750+7627410, based on optical data covering ~250d. From the beginning, the transient shows prominent narrow Balmer lines with P-Cygni profiles, with a blue-shifted absorption component becoming more prominent with time. Along the 3months of the spectroscopic monitoring, .......

Interacting supernovae and supernova impostors. LSQ13zm: an outburst heralds the death of a massive star
Tartaglia et al. 2016 MNRAS 459, 1039
We report photometric and spectroscopic observations of the optical transient LSQ13zm. Historical data reveal the presence of an eruptive episode (that we label as 2013a) followed by a much brighter outburst (2013b) three weeks later, that we argue to be the genuine supernova explosion. This sequence of events closely resem- .......

Optical and near infrared observations of SN 2014ck: an outlier among the Type Iax supernovae
Tomasella, L. et al. 2016 MNRAS 459, 1018
We present a comprehensive set of optical and near-infrared photometric and spectroscopic observations for SN 2014ck, extending from pre-maximum to six months later. These data indicate that SN 2014ck is photometrically nearly identical to SN 2002cx, which is the prototype of the class of peculiar transients named SNe Iax. Similar .......

The spectacular evolution of Supernova 1996al over 15 years: a low energy explosion of a stripped massive star in a highly structured environment
Benetti, S., et al. 2016, MNRAS 456,3296
Spectrophotometry of SN 1996al carried out throughout 15 years is presented. The early photometry suggests that SN 1996al is a Linear type-II supernova, with an absolute peak of MV ~18.2 mag. Early spectra present broad, asymmetric Balmer emissions, with super-imposed narrow lines with P-Cygni profile, and He I features with .......

Massive stars exploding in a He-rich circumstellar medium - IX. SN 2014av, and characterization of Type Ibn SNe
Pastorello, A. et al. 2016, MNRAS 456,853
We present spectroscopic and photometric data of the Type Ibn supernova (SN) 2014av, discovered by the Xingming Observatory Sky Survey. A stringent pre-discovery detection limit indicates that the object was discovered soon after core-collapse. A prompt follow-up campaign arranged by amateur astronomers allows us to monitor the rising phase (lasting .......

Massive stars exploding in a He-rich circumstellar medium - VIII. PSN J07285387+3349106, a highly reddened supernova Ibn
Pastorello, A. et al. 2015 MNRAS 454, 4293
We present spectroscopic and photometric observations for the Type Ibn supernova (SN) dubbed PSN J07285387+3349106. Using data provided by amateur astronomers, we monitored the photometric rise of the SN to maximum light, occurred on 2015 February 18.8 UT (JDmax(V ) = 2457072.0 +/- 0.8). PSN J07285387+3349106 exploded in the inner .......

SN 2011fu: A type IIb Supernova with a luminous double-peaked light curve
Morales-Garoffolo, A. et al. 2015 MNRAS 454, 95
We present optical and near infrared observations of the type IIb supernova (SN) 2011fu from a few days to 300 d after explosion. The SN presents a double-peaked light curve (LC) similar to that of SN 1993J, although more luminous and with a longer cooling phase after the primary peak. .......

Massive stars exploding in a He-rich circumstellar medium - VII. The metamorphosis of ASASSN-15ed from a narrow line Type Ibn to a normal Type Ib SN
Pastorello, A. et al. 2015 MNRAS 453, 3650
We present the results of the spectroscopic and photometric monitoring campaign of ASASSN-15ed. The transient was discovered quite young by the All Sky Automated Survey for SuperNovae (ASAS-SN) survey. Amateur astronomers allowed us to sample the photometric SN evolution around maximum light, which we estimate to have occurred on JD .......

Supernova rates from the SUDARE VST-Omegacam search. I
Cappellaro, E. et al. 2015 A&A 584, 62
We describe the observing strategy, data reduction tools and early results of a supernova (SN) search project, named SUDARE, conducted with the ESO VST telescope aimed at measuring the rate of the different types of SNe in the redshift range 0.2<z<0.8. The search was performed in two of the best-studied .......

On the triple peaks of SNHunt248 in NGC 5806
E. Kankare et al. 2015 A&A 581, L4
We present our findings on a supernova (SN) impostor, SNHunt248, based on optical and near-IR data spanning 15 yrs before discovery, to 1 yr post-discovery. The light curve displays three distinct peaks, the brightest of which is at MR15.0 mag. The post-discovery evolution is consistent with the ejecta from the .......

Explosion of a massive, He-rich star at z=0.16
Elias-Rosa, N. et al. 2015, MNRAS 436, 109
We present spectroscopic and photometric data of the peculiar SN 2001gh, discovered by the 'Southern inTermediate Redshift ESO Supernova Search' (STRESS) at a redshift z=0.16. SN 2001gh has relatively high luminosity at maximum (M_B = -18.55 mag), while the light curve shows a broad peak. An early-time spectrum shows an .......

SN 2013ab: a normal Type IIP supernova in NGC 5669
Bose, S. et al. 2015, MNRAS 450, 2373
We present densely sampled ultraviolet/optical photometric and low-resolution optical spectroscopic observations of the Type IIP supernova 2013ab in the nearby (about 24 Mpc) galaxy NGC 5669, from 2 to 190 d after explosion. Continuous photometric observations, with the cadence of typically a day to one week, were acquired with the .......

SN 2011A: an low-luminosity interacting transient, with a double plateau and strong sodium absorption
de Jaeger, T. et al. 2015, A&A 807, 63
We present optical photometry and spectroscopy of the optical transient SN 2011A. Our data spans 140 days after discovery including BVRIugriz photometry and 11 epochs of optical spectroscopy. Originally classified as a type IIn supernova (SN IIn) due to the presence of narrow HLPH emission, this object shows exceptional characteristics. .......

SN 2009ib: A Type II-P Supernova with an Unusually Long Plateau
Takats, K. et al. 2015, MNRAS 450, 3137
We present optical and near-infrared photometry and spectroscopy of SN 2009ib, a Type II-P supernova in NGC 1559. This object has moderate brightness, similar to those of the intermediate-luminosity SNe 2008in and 2009N. Its plateau phase is unusually long, lasting for about 130 days after explosion. The spectra are similar .......

Massive stars exploding in a He-rich circumstellar medium. VI. Observations of two distant Type Ibn supernova candidates discovered by La Silla-QUEST
Pastorello, A. et al. 2015, MNRAS 449, 1954
We present optical observations of the peculiar stripped-envelope supernovae (SNe) LSQ12btw and LSQ13ccw discovered by the La Silla-QUEST survey. LSQ12btw reaches an absolute peak magnitude of M(g) = -19.3 +- 0.2, and shows an asymmetric light curve. Stringent prediscovery limits constrain its rise time to maximum light to less than .......

Massive stars exploding in a He-rich circumstellar medium. IV. Transitional Type Ibn Supernovae
Pastorello, A. et al. 2015, MNRAS 449, 1921
We present ultraviolet, optical and near-infrared data of the Type Ibn supernovae (SNe) 2010al and 2011hw. SN 2010al reaches an absolute magnitude at peak of M(R) = -18.86 +- 0.21. Its early light curve shows similarities with normal SNe Ib, with a rise to maximum slower than most SNe Ibn. .......

Massive stars exploding in a He-rich circumstellar medium. V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
Pastorello, A. et al. 2015, MNRAS 449, 1941
We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN-006, discovered and monitored by the OGLE-IV survey, and spectroscopically followed by PESSTO at late phases. Stringent pre-discovery limits constrain the explosion epoch with fair precision to JD = 2456203.8 +- 4.0. The rise time to the I-band .......

Spectroscopy of the Type Ia supernova 2011fe past 1000 days
Taubenberger, S. etal. 2015, MNRAS 448, L48
In this letter we present an optical spectrum of SN 2011fe taken 1034 d after the explosion, several hundred days later than any other spectrum of a Type Ia supernova (disregarding light-echo spectra and local-group remnants). The spectrum is still dominated by broad emission features, with no trace of a .......

SN 2012ec: mass of the progenitor from PESSTO follow-up of the photospheric phase
Barbarino, C. et al. 2015, MNRAS 448, 2312
We present the results of a photometric and spectroscopic monitoring campaign of SN 2012ec, which exploded in the spiral galaxy NGC 1084, during the photospheric phase. The photometric light curve exhibits a plateau with luminosity L= 0.9 times 10 to 42 (erg s to -1) and duration ~90 days; which .......

PESSTO : survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects
Smartt et al. 2015, A&A 579, 40
The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. We describe the data reduction strategy and data products which are publicly available through the ESO archive as the Spectroscopic Survey Data Release 1 (SSDR1). PESSTO uses the New Technology .......

Extending the supernova Hubble diagram to z~1.5 with the Euclid space mission
Astier, M. et al. 2014, A&A 572, 80
We forecast dark energy constraints that could be obtained from a new large sample of Type Ia supernovae where those at high redshift are acquired with the Euclid space mission. We simulate a three-prong SN survey: a z < 0.35 nearby sample (8000 SNe), a 0.2 < z < 0.95 .......

The Type IIb SN 2011dh - 2 years of observations and modelling of the lightcurves
Ergon, M. etal. 2014, arXiv1408.0731
We present optical and near-infrared (NIR) photometry and spectroscopy as well as modelling of the lightcurves of the Type IIb supernova (SN) 2011dh. Our extensive dataset spans 2 years, and complemented with Spitzer mid-infrared (MIR) data, we use it to build a 3-732 days optical to MIR bolometric lightcurve. To .......

SN 2013df, a double-peaked IIb supernova from a compact progenitor and an extended H envelope
Morales-Garoffolo, A. et al. 2014, MNRAS 445, 1467
Optical observations of the type IIb SN 2013df from a few days to about 250 days after explosion are presented. These observations are complemented with UV photometry taken by SWIFT up to 60 days post-explosion. The double-peak optical light curve is similar to those of SNe 1993J and 2011fu although .......

Interacting supernovae and supernova impostors. SN 2007sv: the major eruption of a massive star in UGC 5979
Tartaglia, L. et al 2015, MNRAS 447, 117
We report the results of the photometric and spectroscopic monitoring campaign of the transient SN 2007sv. The observables are similar to those of type IIn supernovae, a well-known class of objects whose ejecta interact with pre-existing circum-stellar material. The spectra show a blue continuum at early phases and prominent Balmer .......

The Type IIP Supernova 2012aw in M95: hydrodynamical modelling of the photospheric phase from accurate spectrophotometric monitoring.
Dall'Ora, M. etal. 2014, ApJ 787, 139
We present an extensive optical and near-infrared photometric and spectroscopic campaign of the type IIP supernova SN 2012aw. The dataset densely covers the evolution of SN 2012aw shortly after the explosion up to the end of the photospheric phase, with two additional photometric observations collected during the nebular phase, to .......

Asiago Supernova classification program: blowing out the first two hundreds candles
Tomasella, L., etal 2014, Astronomische Nachrichten 335, 841
We present the compilation of the first 221 supernovae classified during the Asiago Classification Program (ACP). The details of transients classification and the preliminarily reduced spectra, in fits format, are immediately posted on the Padova-Asiago SN group web site. The achieved performances for the first 2 years of the ACP .......

The supernova CSS121015:004244+132827: a clue for understanding super-luminous supernovae
Benetti et al. 2014, MNRAS 441, 289
We present optical photometry and spectra of the super luminous type II/IIn supernova CSS121015:004244+132827 (z=0.2868) spanning epochs from -30 days (rest frame) to more than 200 days after maximum. CSS121015 is one of the more luminous supernova ever found and one of the best observed. The photometric evolution is characterized .......

The first month of evolution of the slow-rising Type IIP SN 2013ej in M74
Valenti, S. etal. 2014, MNRAS 438, L101
We present early photometric and spectroscopic observations of SN 2013ej, a bright type IIP supernova in M74. SN 2013ej is one of the closest SNe ever discovered. The available archive images and the early discovery help to constrain the nature of its progenitor. The earliest detection of this explosion was .......

SN2012ca: a stripped envelope core-collapse SN interacting with dense circumstellar medium
Inserra, C. etal. 2014, MNRAS 437, L51
We report optical and near-infrared observations of SN2012ca with the Public ESO Spectroscopy Survey of Transient Objects (PESSTO), spread over one year since discovery. The supernova (SN) bears many similarities to SN1997cy and to other events classified as Type IIn but which have been suggested to have a thermonuclear origin .......

Low luminosity Type II supernovae - II. Pointing towards moderate mass precursors
Spiro, S. etal. 2014, MNRAS 439, 2873
We present new data for five under-luminous type II-plateau supernovae (SNe IIP), namely SN 1999gn, SN 2002gd, SN 2003Z, SN 2004eg and SN 2006ov. This new sample of low-luminosity SNe IIP (LL SNe IIP) is analyzed together with similar objects studied in the past. All of them show a flat .......

SN2011hs: a Fast and Faint Type IIb Supernova from a Supergiant Progenitor
Bufano, F. etal. 2014, MNRAS 439, 1807
Observations spanning a large wavelength range, from X-ray to radio, of the Type IIb supernova 2011hs are presented, covering its evolution during the first year after explosion. The optical light curve presents a narrower shape and a fainter luminosity at peak than previously observed for Type IIb SNe. High expansion .......

PESSTO monitoring of SN 2012hn: further heterogeneity among faint Type I supernovae
Valenti, S. et al 2014, MNRAS 437, 1519
We present optical and infrared monitoring data of SN 2012hn collected by the Public European Southern Observatory Spectroscopic Survey for Transient Objects. We show that SN 2012hn has a faint peak magnitude (MR ~ -15.65) and shows no hydrogen and no clear evidence for helium in its spectral evolution. Instead, .......

On the progenitor of the Type Ic SN 2013dk in the Antennae galaxies
Elias-Rosa, N. etal. 2013, MNRAS 436, 109
We report the results of our search for the progenitor candidate of SN 2013dk, a Type Ic supernova (SN) that exploded in the Antennae galaxy system. We compare pre-explosion Hubble Space Telescope (HST) archival images with SN images obtained using adaptive optics at the ESO Very Large Telescope. We isolate .......