Browsing by Author "Pastorello, A."

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    450 d of Type II SN 2013ej in optical and near-infrared
    (OXFORD UNIV PRESS, 2016) Yuan, Fang; Jerkstrand, A.; Valenti, S.; Sollerman, J.; Seitenzahl, I. R.; Pastorello, A.; Schulze, S.; Chen, T. W.; Childress, M. J.; Fraser, M.; Fremling, C.; Kotak, R.; Ruiter, A. J.; Schmidt, B. P.; Smartt, S. J.; Taddia, F.; Terreran, G.; Tucker, B. E.; Barbarino, C.; Benetti, S.; Elias Rosa, N.; Gal Yam, A.; Howell, D. A.; Inserra, C.; Kankare, E.; Lee, M. Y.; Li, K. L.; Maguire, K.; Margheim, S.; Mehner, A.; Ochner, P.; Sullivan, M.; Tomasella, L.; Young, D. R.
    We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude M-V =-17.6) but a small 56Ni production of similar to 0.023 M-circle dot. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the H a profile typical for a Type IIL. During transition to the radioactive decay tail at similar to 100 d, we find the SN to grow bluer in B - V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from Co-56 decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral models with a M-ZAMS = 12-15 M-circle dot progenitor. The derived mass range is similar to but not higher than the mass estimated for Type IIP progenitors. This is against the idea that Type IIL are from more massive stars. Observations are consistent with the SN having a progenitor with a relatively low-mass envelope.
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    Interacting supernovae and supernova impostors. LSQ13zm : an outburst heralds the death of a massive star
    (2016) Tartaglia, L.; Pastorello, A.; Sullivan, M.; Baltay, C.; Rabinowitz, D.; Nugent, P.; Drake, A. J.; Djorgovski, S. G.; Gal-Yam, A.; Bauer, Franz Erik; Barsukova, E. A.; Goranskij, V. P.; Valeev, A. F.; Fatkhullin, T.; Schulze, S.; Mehner, A.; Fabrika, S.; Taubenberger, S.; Nordin, J.; Valenti, S.
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    Luminous Type II supernovae for their low expansion velocities
    (2020) Rodríguez, O.; Pignata, Giuliano; Anderson, J. P.; Moriya, T. J.; Clocchiatti, Alejandro; Förster, F.; Prieto, J. L.; Phillips, M. M.; Burns, C. R.; Contreras, C.; Folatelli, G.; Gutiérrez, C. P.; Hamuy, M.; Morrell, N. I.; Stritzinger, M. D.; Suntzeff, N. B.; Benetti, S.; Cappellaro, E.; Elias Rosa, N.; Pastorello, A.; Turatto, M.; Maza, J.; Antezana, R.; Cartier, R.; González, L.; Haislip, J. B.; Kouprianov, V.; López, P.; Marchi Lasch, S.; Reichart, D.
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    Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
    (2015) Pastorello, A.; Wyrzykowski, L.; Valenti, S.; Prieto, J. L.; Kozlowski, S.; Udalski, A.; Elias-Rosa, N.; Morales-Garoffolo, A.; Anderson, J. P.; Benetti, S.; Bersten, M.; Botticella, M. T.; Cappellaro, E.; Fasano, G.; Fraser, M.; Gal-Yam, A.; Gillone, M.; Graham, M. L.; Greiner, J.; Hachinger, S.; Howell, D. A.; Inserra, C.; Parrent, J.; Rau, A.; Schulze, S.; Smartt, S. J.; Smith, K. W.; Turatto, M.; Yaron, O.; Young, D. R.; Kubiak, M.; Szymanski, M. K.; Pietrzynski, G.; Soszynski, I.; Ulaczyk, K.; Poleski, R.; Pietrukowicz, P.; Skowron, J.; Mroz, P.
    We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN-006, discovered and monitored by the Optical Gravitational Lensing Experiment-IV survey, and spectroscopically followed by Public ESO Spectroscopic Survey of Transient Objects (PESSTO) at late phases. Stringent pre-discovery limits constrain the explosion epoch with fair precision to JD = 245 6203.8 +/- 4.0. The rise time to the I-band light-curve maximum is about two weeks. The object reaches the peak absolute magnitude M-I = -19.65 +/- 0.19 on JD = 245 6218.1 +/- 1.8. After maximum, the light curve declines for about 25 d with a rate of 4 mag (100 d)(-1). The symmetric I-band peak resembles that of canonical Type Ib/c supernovae (SNe), whereas SNe Ibn usually exhibit asymmetric and narrower early-time light curves. Since 25 d past maximum, the light curve flattens with a decline rate slower than that of the Co-56-Fe-56 decay, although at very late phases it steepens to approach that rate. However, other observables suggest that the match with the Co-56 decay rate is a mere coincidence, and the radioactive decay is not the main mechanism powering the light curve of OGLE-2012-SN-006. An early-time spectrum is dominated by a blue continuum, with only a marginal evidence for the presence of He I lines marking this SN type. This spectrum shows broad absorptions bluewards than 5000 angstrom, likely O II lines, which are similar to spectral features observed in superluminous SNe at early epochs. The object has been spectroscopically monitored by PESSTO from 90 to 180 d after peak, and these spectra show the typical features observed in a number of SN 2006jc-like events, including a blue spectral energy distribution and prominent and narrow (v(FWHM) approximate to 1900 km s(-1)) He I emission lines. This suggests that the ejecta are interacting with He-rich circumstellar material. The detection of broad (10(4) km s(-1)) O I and Ca II features likely produced in the SN ejecta (including the [OI] lambda lambda 6300,6364 doublet in the latest spectra) lends support to the interpretation of OGLE-2012-SN-006 as a core-collapse event.
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    PESSTO : survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects
    (2015) Smartt, S. J.; Valenti, S.; Fraser, M.; Inserra, C.; Young, D. R.; Sullivan, M.; Bauer, Franz Erik; Clocchiatti, Alejandro; Romero Cañizales, Cristina; Schulze, S.; Pastorello, A.; Benetti, S.; Gal-Yam, A.; Knapic, C.; Molinaro, M.; Smareglia, R.; Smith, K. W.; Taubenberger, S.; Yaron, O.; Anderson, J. P.; Ashall, C.; Balland, C.; Baltay, C.; Barbarino, C.; Baumont, S.; Bersier, D.; Blagorodnova, N.; Bongard, S.; Botticella, M. T.; Bufano, F.; Bulla, M.; Cappellaro, E.; Campbell, H.; Cellier-Holzem, F.; Chen, T. W.; Childress, M. J.; Contreras, C.; Dall’Ora, M.; Danziger, J.; de Jaeger, T.; De Cia, A.; Della Valle, M.; Dennefeld, M.; Elias Rosa, N.; Elman, N.; Feindt, U.; Fleury, M.; Gall, E.; González Gaitan, S.; Galbany, L.; Morales Garoffolo, A.; Greggio, L.; Guillou, L. L.; Hachinger, S.; Hadjiyska, E.; Hage, P. E.; Hillebrandt, W.; Hodgkin, S.; Hsiao, E. Y.; James, P. A.; Jerkstrand, A.; Kangas, T.; Kankare, E.; Kotak, R.; Kromer, M.; Kuncarayakti, H.; Leloudas, G.; Lundqvist, P.; Lyman, J. D.; Hook, I. M.; Maguire, K.; Manulis, I.; Margheim, S. J.; Mattila, S.; Maund, J. R.; Mazzali, P. A.; McCrum, M.; McKinnon, R.; Moreno Raya, M. E.; Nicholl, M.; Nugent, P.; Pain, R.; Pignata, Giuliano; Phillips, M. M.; Polshaw, J.; Pumo, M. L.; Rabinowitz, D.; Reilly, E.; Scalzo, R.; Schmidt, B.; Sim, S.; Sollerman, J.; Taddia, F.; Tartaglia, L.; Terreran, G.; Tomasella, L.; Turatto, M.; Walker, E.; Walton, N. A.; Wyrzykowski, L.; Yuan, F.; Zampieri, L.
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    Photometric and spectroscopic evolution of the interacting transient AT 2016jbu(Gaia16cfr)
    (2022) Brennan, S. J.; Fraser, M.; Johansson, J.; Pastorello, A.; Kotak, R.; Stevance, H. F.; Chen, T-W; Eldridge, J. J.; Bose, S.; Brown, P. J.; Callis, E.; Cartier, R.; Dennefeld, M.; Dong, Subo; Duffy, P.; Elias-Rosa, N.; Hosseinzadeh, G.; Hsiao, E.; Kuncarayakti, H.; Martin-Carrillo, A.; Monard, B.; Nyholm, A.; Pignata, G.; Sand, D.; Shappee, B. J.; Smartt, S. J.; Tucker, B. E.; Wyrzykowski, L.; Abbot, H.; Benetti, S.; Bento, J.; Blondin, S.; Chen, Ping; Delgado, A.; Galbany, L.; Gromadzki, M.; Gutierrez, C. P.; Hanlon, L.; Harrison, D. L.; Hiramatsu, D.; Hodgkin, S. T.; Holoien, T. W-S; Howell, D. A.; Inserra, C.; Kankare, E.; Kozlowski, S.; Muller-Bravo, T. E.; Maguire, K.; McCully, C.; Meintjes, P.; Morrell, N.; Nicholl, M.; O'Neill, D.; Pietrukowicz, P.; Poleski, R.; Prieto, J. L.; Rau, A.; Reichart, D. E.; Schweyer, T.; Shahbandeh, M.; Skowron, J.; Sollerman, J.; Soszynski, I; Stritzinger, M. D.; Szymanski, M.; Tartaglia, L.; Udalski, A.; Ulaczyk, K.; Young, D. R.; van Leeuwen, M.; van Soelen, B.
    We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of M-V similar to-18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s(-)(1) seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s(-1) seen in broad absorption from some high-velocity material. Late-time spectra (similar to+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He I, and Ca II. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H alpha among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients.
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    Progenitor, environment, and modelling of the interacting transient AT 2016jbu (Gaia16cfr)
    (2022) Brennan, S. J.; Fraser, M.; Johansson, J.; Pastorello, A.; Kotak, R.; Stevance, H. F.; Chen, T-W; Eldridge, J. J.; Bose, S.; Brown, P. J.; Callis, E.; Cartier, R.; Dennefeld, M.; Dong, Subo; Duffy, P.; Elias-Rosa, N.; Hosseinzadeh, G.; Hsiao, E.; Kuncarayakti, H.; Martin-Carrillo, A.; Monard, B.; Pignata, G.; Sand, D.; Shappee, B. J.; Smartt, S. J.; Tucker, B. E.; Wyrzykowski, L.; Abbot, H.; Benetti, S.; Bento, J.; Blondin, S.; Chen, Ping; Delgado, A.; Galbany, L.; Gromadzki, M.; Gutierrez, C. P.; Hanlon, L.; Harrison, D. L.; Hiramatsu, D.; Hodgkin, S. T.; Holoien, T. W-S; Howell, D. A.; Inserra, C.; Kankare, E.; Kozlowski, S.; Muller-Bravo, T. E.; Maguire, K.; McCully, C.; Meintjes, P.; Morrell, N.; Nicholl, M.; O'Neill, D.; Pietrukowicz, P.; Poleski, R.; Prieto, J. L.; Rau, A.; Reichart, D. E.; Schweyer, T.; Shahbandeh, M.; Skowron, J.; Sollerman, J.; Soszynski, I; Stritzinger, M. D.; Szymanski, M.; Tartaglia, L.; Udalski, A.; Ulaczyk, K.; Young, D. R.; van Leeuwen, M.; van Soelen, B.
    We present the bolometric light curve, identification and analysis of the progenitor candidate, and preliminary modelling of AT 2016jbu (Gaia16cfr). We find a progenitor consistent with a similar to 22-25 M-circle dot yellow hypergiant surrounded by a dusty circumstellar shell, in agreement with what has been previously reported. We see evidence for significant photometric variability in the progenitor, as well as strong H alpha emission consistent with pre-existing circumstellar material. The age of the environment, as well as the resolved stellar population surrounding AT 2016jbu, supports a progenitor age of >10 Myr, consistent with a progenitor mass of similar to 22 M-circle dot. A joint analysis of the velocity evolution of AT 2016jbu and the photospheric radius inferred from the bolometric light curve shows the transient is consistent with two successive outbursts/explosions. The first outburst ejected material with velocity similar to 650 km s(-1), while the second, more energetic event ejected material at similar to 4500 km s(-1). Whether the latter is the core collapse of the progenitor remains uncertain. We place a limit on the ejected Ni-56 mass of <0.016 M-circle dot. Using the Binary Population And Spectral Synthesis (BPASS) code, we explore a wide range of possible progenitor systems and find that the majority of these are in binaries, some of which are undergoing mass transfer or common-envelope evolution immediately prior to explosion. Finally, we use the SuperNova Explosion Code (SNEC) to demonstrate that the low-energy explosions within some of these binary systems, together with sufficient circumstellar material, can reproduce the overall morphology of the light curve of AT 2016jbu.
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    SN 2004aw
    (2006) Taubenberger, S.; Pastorello, A.; Mazzali, P. A.; Valenti, S.; Pignata, G.; Sauer, D. N.; Arbey, A.; Baernbantner, O.; Benetti, S.; Della Valle, A.; Deng, J.; Elias-Rosa, N.; Filippenko, A. V.; Foley, R. J.; Goobar, A.; Kotak, R.; Li, W.; Meikle, P.; Mendez, J.; Patat, F.; Pian, E.; Ries, C.; Ruiz-Lapuente, P.; Salvo, M.; Stanishev, V.; Turatto, M.; Hillebrandt, W.
    Optical and near-infrared (near-IR) observations of the Type Ic supernova (SN Ic) 2004aw are presented, obtained from -3 to +413 d with respect to the B-band maximum. The photometric evolution is characterized by a comparatively slow post-maximum decline of the light curves. The peaks in redder bands are significantly delayed relative to the bluer bands, the I-band maximum occurring 8.4 d later than that in B. With an absolute peak magnitude of -18.02 in the V band the SN can be considered fairly bright, but not exceptional. This also holds for the U through I bolometric light curve, where SN 2004aw has a position intermediate between SNe 2002ap and 1998bw. Spectroscopically SN 2004aw provides a link between a normal SN Ic like SN 1994I and the group of broad-lined SNe Ic. The spectral evolution is rather slow, with a spectrum at day +64 being still predominantly photospheric. The shape of the nebular [O-I] lambda lambda 6300, 6364 line indicates a highly aspherical explosion. Helium cannot be unambiguously identified in the spectra, even in the near-IR. Using an analytical description of the light-curve peak we find that the total mass of the ejecta in SN 2004aw is 3.5-8.0 M-circle dot, significantly larger than that in SN 1994I, although not as large as in SN 1998bw. The same model suggests that about 0.3 M-circle dot of Ni-56 has been synthesized in the explosion. No connection to a GRB can be firmly established.
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    SNe 2013K and 2013am: observed and physical properties of two slow, normal Type IIP events
    (2018) Tomasella, L.; Cappellaro, E.; Pumo, M. L.; Jerkstrand, A.; Benetti, S.; Elias Rosa, N.; Fraser, M.; Inserra, C.; Pastorello, A.; Bauer, Franz Erik
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    Supernova 2011db near Pgc 49027 = Psn 13490590+1714005
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Tomasella, L.; Ochner, P.; Valenti, S.; Benetti, S.; Pastorello, A.
    Report the Catalina Real-time Transient Survey's discovery of an apparent supernova in unfiltered survey images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011db May 12.30 13 49 05.90 +17 14 00.5 17.4 6".4 E, 17".1 S This variable was designated PSN J13490590+1714005 when posted at the Central Bureau's TOCP webpage and is here designated SN 2011db based on the spectroscopic report below. Further magnitudes for 2011db: Apr. 25.22 UT, [20.0 (Catalina Sky Survey); May 13.357, 17.2 (Joseph Brimacombe, Cairns, Australia; from six stacked 1200-s images taken remotely using a 51-cm RCOS telescope + red filter + STL11K camera at New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 05s.95, 13'59".6, which is near PGC 49027; his image is posted at the following website URL: http://www.flickr.com/photos/43846774@N02/5725585922/). L. Tomasella, P. Ochner, S. Valenti, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 390-810 nm; resolution 2.2 nm) of PSN 13490590+1714005 = SN 2011db, obtained on May 25.89 UT by the Service Telescope Operator Team with the Ekar-Copernicus 1.82-m telescope (+ AFOSC), is a type-II supernova, similar to SN 2007od (Inserra et al. 2011, posted at website URL http://lanl.arxiv.org/abs/1102.5468) at a couple of weeks after explosion....
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    Supernova 2011dc = Psn 14585651+6554083
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Tomasella, L.; Ochner, P.; Valenti, S.; Benetti, S.; Pastorello, A.
    Report the Catalina Real-time Transient Survey's discovery of an apparent supernova in unfiltered Catalina Sky Survey images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011dc May 14.32 14 58 56.51 +65 54 08.3 17.0 9".5 W, 2".0 S This variable was designated PSN 14585651+6554083 when posted at the Central Bureau's TOCP webpage and is here designated SN 2011dc based on the spectroscopic report below. Further magnitudes for 2011dc: Apr. 2.37 UT, [19.0 (Catalina Sky Survey); May 15.237, 17.1 (Joseph Brimacombe, Cairns, Australia; from four stacked 1200-s images taken remotely using a 51-cm RCOS telescope + red filter + STL11K camera at New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 56s.5, 07".8). Brimacombe's image is posted at http://www.flickr.com/photos/43846774@N02/5729478332/. L. Tomasella, P. Ochner, S. Valenti, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a noisy spectrogram (range 390-810 nm; resolution 2.2 nm) of PSN 14585651+6554083 = SN 2011dc, obtained on May 26.03 UT under poor weather conditions by the Service Telescope Operator Team with the Ekar-Copernicus 1.82-m telescope (+ AFOSC), suggests that 2011dc is likely a type-I supernova; if a broad absorption measured at 644.0 nm is identified with Si II 635.5-nm, the redshift of 2011dc is between 0.04 and 0.05....
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    Supernova 2011dj in Pgc 45427 = Psn J13070669-0110440
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Baroni, S.; Buzzi, L.; Concari, P.; Foglia, S.; Galli, G.; Tombelli, M.; Tomasella, L.; Ochner, P.; Valenti, S.; Benetti, S.; Pastorello, A.
    Report the Catalina Real-time Transient Survey's discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images, as tabulated below. The variable was designated PSN J13070669-0110440 when posted on the Central Bureau's TOCP webpage and is here designated SN 2011dj based on the spectroscopic report below. SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011dj June 4.21 13 07 06.69 - 1 10 44.0 15.8 15".7 E, 7".2 S Additional CCD magnitudes for 2011dj: May 25.28 UT, [20.0 (CSS); June 4.563, R = 15.7 (Joseph Brimacombe, Coral Towers Observatory, Cairns, Australia; 30-cm reflector + STL6K camera; five 600-s stacked images; position end figures 06s.67, 45".5); 7.567, R = 15.1 (S. Baroni, L. Buzzi, P. Concari, S. Foglia, G. Galli, and M. Tombelli; remotely using a 0.18-m f/2.8 reflector at the Tzec Maun Observatory, Moorook, Australia; position end figures 06s.69, 45".0); 9.424, R = 15.4 (Baroni et al.). Foglia adds that nothing is visible at the position of 2011dj in NEAT images from 2002 Apr. 14 and 2003 Apr. 9 (no limiting magnitudes provided). Brimacombe's image is posted at website URL http://www.flickr.com/photos/43846774@N02/5799770906/. Foglia notes that their image from June 7 is posted at the following website URL: URL http://www.apan.it/pianetini/pub/psn/pgc45427.htm. L. Tomasella, P. Ochner, S. Valenti, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 390-810 nm; resolution 2.2 nm) of PSN J13070669-0110440 = SN 2011dj, obtained on June 6.87 UT with the Ekar-Copernicus 1.82-m telescope (+ AFOSC), shows it to be a type-Ia supernova, a couple of days before maximum....
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    Supernova 2011fz in UGC 12271 = Psn J22582030+0217299
    (2011) Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; McNaught, R. H.; Garradd, G.; Beshore, E. C.; Larson, S. M.; Christensen, E.; Valenti, S.; Benetti, S.; Tomasella, L.; Ochner, P.; Pastorello, A.
    Report the discovery of an apparent supernova in public images from the Catalina Sky Survey (CSS). SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011fz Sep. 18.28 22 58 20.30 + 2 17 29.9 16.6 13".3 W, 23".0 S The new object was designated PSN J22582030+0217299 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011fz based on the spectroscopic report below. Additional unfiltered CCD magnitudes for 2011fz: July 2.38 UT, 19.0 (CSS); Sept. 19.381, 17.9 (Joseph Brimacombe, Cairns, Australia; position end figures 20s.26, 29".2; image posted at website URL http://www.flickr.com/photos/43846774@N02/6170077719/); 19.89, 17.1 (Nick James, Chelmsford, Essex, England; Celestron 11 telescope + ST9XE camera; position end figures 20s.26, 29".0; UCAC-3 reference stars). S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram of PSN J22582030+0217299 = SN 2011fz, obtained on Sept. 24.95 UT, suggests that it is a type-Ib/c supernova observed several weeks after maximum. Using the distance module of 34.14 for UGC 12271 (Mould et al. 2000, Ap.J. 529, 786; via the NED website) and an apparent magnitude of 17.7, 2011fz has an absolute magnitude of -16.45, which is consistent with magnitudes of type-Ib/c supernovae at this phase....
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    Supernova 2011ga in Pgc 69458 = Psn J22402742+0311580
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Valenti, S.; Benetti, S.; Tomasella, L.; Ochner, P.; Pastorello, A.; Marion, G. H.
    Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011ga Sep. 18.25 22 40 27.42 + 3 11 58.0 17.3 18".2 W, 7".4 N The new object was designated PSN J22402742+0311580 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011ga based on the spectroscopic report below. Additional CCD magnitudes for 2011ga (unfiltered unless noted otherwise: July 2.38 UT, [19.3 (CSS); Sept. 19.179, 16.5 (Joseph Brimacombe, Cairns, Australia; infrared filter, wavelength > 700 nm; image posted at URL http://www.flickr.com/photos/43846774@N02/6177998402/); 19.320, 17.2 (Brimacombe; position end figures 27s.38, 58".9; image posted at website URL http://www.flickr.com/photos/43846774@N02/6168832131/). S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram of PSN J22402742+0311580 = SN 2011ga, obtained on Sept. 24.91 UT, suggests that it is a type-Ia supernova observed close to B-band maximum. The velocity of the ejected material, as deduced from the position of the minimum of the Si II lines, is about 10600 km/s. G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm) of PSN J22402742+0311580 = 2011ga was obtained on Sept. 27 UT by Marion with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that the object is a type-Ia supernova a few days after maximum light. The best-fit template spectrum is that of SN 2003du at +2 days. The velocity of the Si II 635.5-nm feature is estimated to be approximately 10800 km/s, using the SNID estimated redshift of z = 0.040....
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    Supernova 2011gb = Psn J01334294+3448371
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Denisenko, D.; Brimacombe, J.; Valenti, S.; Benetti, S.; Tomasella, L.; Ochner, P.; Pastorello, A.
    Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gb Sep. 24.30 1 33 42.94 +34 48 37.1 16.1 4".5 W, 1".1 S The new object was designated PSN J01334294+3448371 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011gb based on the spectroscopic report below. Additional CCD magnitudes for 2011gb (unfiltered unless noted otherwise): Jan. 16.23, [18.5 (CSS); Sept. 24.850, 15.9 (D. Denisenko, Moscow, Russia; 0.20-m f/5 reflector + Meade DSI Pro II camera; position end figures 42s.84, 36".8; image posted at the following website URL: http://pics.livejournal.com/bigdenru/pic/000a957p/); 24.897, 15.5 (Paolo Corelli, Pagnacco, Italy; 0.45-m f/4.5 telescope; position end figures 42s.8, 36".8; nearby galaxy centered at position end figures 43s.35, 37".9); 25.187, 16.3 (J. Brimacombe, Cairns, Australia; position end figures 42s.86, 37".0; image posted at URL http://www.flickr.com/photos/43846774@N02/6186780582/); 26.875, 16.3 (Nick James, Chelmsford, Essex, England; Celestron 11 telescope + ST9XE camera; position end figures 42s.84, 36".9; UCAC-3 reference stars). S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram of PSN J01334294+3448371 = SN 2011gb, obtained on Sept. 25.06 UT, suggests that it is a type-Ia supernova observed a few weeks after B-band maximum at a redshift z = 0.014....
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    Supernova 2011gf = Psn J21122427-0748521
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Valenti, S.; Benetti, S.; Tomasella, L.; Ochner, P.; Pastorello, A.; Marion, G. H.
    Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gf Sep. 18.19 21 12 24.27 - 7 48 52.1 16.6 23".5 E, 21".8 N This variable was designated PSN J21122427-0748521 when it was posted on the Central Bureau's TOCP webpage and is here designated SN 2011gf based on the spectroscopic report below. Joseph Brimacombe, Cairns, Australia, reports unfiltered CCD mag 16.1 and position end figures 24s.31, 51".8 from an image taken on Sept. 19.266 UT; he has posted his image at the following website URL: http://www.flickr.com/photos/43846774@N02/6167975455/. S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 360-810 nm; resolution 2.2 nm) of PSN J21122427-0748521 = SN 2011gf, obtained on Sept. 25.90 UT, suggestss that it is a type-Ia supernova. Cross-correlation with a library of supernova spectra via the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383; available at URL https://gelato.tng.iac.es/login.cgi), suggest a normal type-Ia supernova close to the B-band maximum at a redshift of z = 0.0277 (Sloan Digital Sky Survey, via the NED website). The expansion velocity deduced from the Si II 635.5-nm minimum is about 11100 km/s. G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf of the CfA Supernova Group, report that a spectrum (range 340-740 nm) of PSN J21122427-0748521 = 2011gf was obtained on Sept. 27 UT by Marion with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011gf is a type-Ia supernova a few days after maximum light. The best-fit template spectrum is that of SN 2007F at +4 days. The velocity of the Si II 635.5-nm feature is estimated to be approximately 11600 km/s, using the SNID estimated redshift of z = 0.027....
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    Supernova 2011gg = Psn J00462108-0909277
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Valenti, S.; Benetti, S.; Tomasella, L.; Ochner, P.; Pastorello, A.
    Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gg Sep. 20.32 00 46 21.08 - 9 09 27.7 17.6 4".5 W, 1".1 S This variable was designated PSN J00462108-0909277 when it was posted on the Central Bureau's TOCP webpage and is here designated SN 2011gg based on the spectroscopic report below. Further unfiltered CCD magnitudes for 2011gg: Sept. 24.34 UT, 17.4 (CSS); 27.407, 16.9 (Joseph Brimacombe, Cairns, Australia; position end figures 21s.05, 28".6; image posted at the following website URL: http://www.flickr.com/photos/43846774@N02/6191346245/). S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 360-810 nm; resolution 2.2 nm) of PSN J00462108-0909277 = SN 2011gg, obtained on Sept. 26.01 UT, suggests that it is a type-Ia supernova. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) suggests a normal type-Ia supernova about one week before the B-band maximum at a redshift z = 0.055. The expansion velocity derived from the Si II 635.5-nm minimum is then about 10500 km/s....
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    Supernova 2011gh in NGC 2405 = Psn J07321603+2554300
    (2011) Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; McNaught, R. H.; Garradd, G.; Beshore, E. C.; Larson, S. M.; Christensen, E.; Valenti, S.; Benetti, S.; Tomasella, L.; Ochner, P.; Pastorello, A.
    Report the discovery of an apparent supernova in public images from the Catalina Sky Survey. SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gh Sep. 19.48 7 32 14.94 +25 54 14.6 18.3 12".5 E, 8".7 S Drake originally posted position end figures 16s.03, 30".0 on the Central Bureau's TOCP webpage, and the provisional designation PSN J07321603+2554300 was assigned to this varible; the designation SN 2011gh is assigned here, based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2011gh (unfiltered unless noted otherwise): Apr. 29.17 UT, [19.5 (Mount Lemmon Survey; via Drake); Sept. 20.476, 19.1 (Joseph Brimacombe, Cairns, Australia); 21.475, R = 19.0 (Brimacombe). Brimacombe's Sept. 20 image is posted at URL http://www.flickr.com/photos/43846774@N02/6167919130/; his Sept. 21 image is at http://www.flickr.com/photos/43846774@N02/6174516626/. S. Valenti, S. Benetti, L. Tomasella, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 360-810 nm; resolution 2.2 nm) of PSN J07321603+2554300 = SN 2011gh, obtained on Sept. 26.10 UT, suggests that it is a type-Ib/c supernova. Cross-correlation with a library of supernova spectra via the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383; available at URL https://gelato.tng.iac.es/login.cgi), suggests a type-Ib/c supernova a few weeks after B-band maximum....
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    Supernova 2011gp in UGC 3119 = Psn J04390804+1131516
    (2011) Howerton, S.; Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Valenti, S.; Cappellaro, E.; Benetti, S.; Turatto, M.; Pastorello, A.
    Report the discovery of an apparent supernova in public images from the Mount Lemmon Survey: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gp Sep. 30.45 4 39 08.04 +11 31 51.6 18.4 5".1 E, 1".7 N This variable was designated PSN J04390804+1131516 when it was posted on the Central Bureau's TOCP webpage and is here designated SN 2011?? based on the spectroscopic report below. S. Valenti, E. Cappellaro, S. Benetti, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica (INAF); M. Turatto, Osservatorio Astronomico di Trieste, INAF; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 360-810 nm; resolution 2.2 nm) of PSN J04390804+1131516 = SN 2011gp, obtained on Sept. 30.95 UT with the Ekar-Copernico 1.82-m telescope (+ AFOSC), shows a red continuum, strong H_alpha emission, Na I D, and other lines typical of type-II supernovae. Cross-correlation with a library of supernova spectra via the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024), suggests that 2011gp is a couple of months after maximum light....
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    Supernova 2011gs = Psn J04210999+1328044
    (2011) Drake, A. J.; Djorgovski, S. G.; Mahabal, A.; Graham, M. J.; Williams, R.; Prieto, J. L.; Catelan, Marcio; Beshore, E. C.; Larson, S. M.; Christensen, E.; Bufano, F.; Valenti, S.; Pastorello, A.
    Report the discovery of an apparent supernova in unfiltered Catalina Sky Survey (CSS) images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011gs Sep. 23.46 4 21 09.99 +13 28 04.4 17.4 10".1 E, 3".7 S This variable was designated PSN J04210999+1328044 when it was posted on the Central Bureau's TOCP webpage and is here designated SN 2011gs based on the spectroscopic report below. Further CCD magnitudes for 2011gs: Mar. 29.15 UT, [19.4 (CSS); Sept. 29.39, 17.6 (CSS); Oct. 2.131, R = 18.9 (Federica Luppi, Varese, Italy; 0.36-m f/7.9 reflector + Bessell R filter; position end figures 10s.03, 04".5; CMC-14 catalogue reference stars; image posted at website URL http://www.astrogeo.va.it/pub/TOCP/PSN_J04210999+1328044.jpg). F. Bufano, Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Catania; and S. Valenti and A. Pastorello, INAF, Osservatorio Astronomico di Padova, on behalf of a larger collaboration, report that a spectrum of PSN J04210999+1328044 = SN 2011gs, obtained on Oct. 1.95 UT with the Ekar-Copernico 1.82-m telescope (+ AFOSC), shows it to be a type-Ia supernova. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) suggests a normal type-Ia supernova about 30 after its B-band maximum (the deduced redshift is 0.027).