Observational constraints on the progenitor of core-collapse supernovae

It is well-known that some massive stars evolve to an end state which results in the collapse of the stellar core, as the hydrostatic pressure can no longer support gravity, leading to powerful explosions called supernovae (SNe). Even with over 6000 known SNe, we have only direct information about the progenitor star for a handful of explosions. Here, I summarise the observational constraints of the massive progenitor stars of several core-collapse supernovae

LIGO/Virgo S191204r: GRAWITA VST-ESO PARANAL transient candidates discovery

We report the results of the observation of the field of the gravitational wave event S191204r (GCN circular #26334) obtained with the VLT Survey Telescope (VST) equipped with Omegacam (described in GCN 26334, Proposal ID ESO 0104.D-0049). Images were analised using our image difference pipelines (Brocato et al. 2018 MNRAS, 474,1). As reference images we used DECAM archive images retrieved from https://datalab.noao.edu/sia/des_dr1. The final vetting was done via visual inspection. We detected the following three interesting candidates: Name | RA | Dec | MJD | Mag VSTJ044435.43-332755.7 | 04:44:35.432 | -33:27:55.69 | 58222.081 | 21.5 +/- 0.1 VSTJ051111.58-373132.0 | 05:11:11.576 | -37:31:32.04 | 58822.079 | 20.6 +/- 0.1 VSTJ051052.17-335413.9 | 05:10:52.168 | -33:54:13.95 | 58823.140 | 22.2 +/- 0.2 The transients were detected at multiple epochs. Here we report epoch and magnitude for the brightest detection. All the transients appear projected near a galaxy. In particular GWd_S191205r_12093 is located 7.4 arcsec from the nucleus of GLADE131392 which distance is 178Mpc (GLADE catalog). The small distance appears to exclude that this transient is related to the GW event. -- Too short? See why http://www.emailcharter.org/ >>>>>>>>>>>>>>>>>>>> Aniello Grado, PhD Ricercatore Astronomo INAF- Osservatorio Astronomico di Capodimonte Via Moiariello 16 80131 Napoli ITALIA Tel: 0039 0815575547 Fax: 0039 0815575433 >>>>>>>>>>>>>>>>>>>

LIGO/Virgo S191204r: correction to GRAWITA GCN 26390

We realised that the text of GCN 26390 was submitted while still incomplete. The correct text is the following: We report the results of the observation of the field of the gravitational wave event S191204r (GCN 26334) obtained with the VLT Survey Telescope (VST) equipped with Omegacam (described in GCN 26334, Proposal ID ESO 0104.D-0049). Images were analised using our image difference pipelines (Brocato et al. 2018 MNRAS, 474,1). As reference images we used DECAM archive images retrieced from https://datalab.noao.edu/sia/des_dr1 . The final vetting was done via visual inspection. We detected the following three interesting candidates: Name | RA | Dec | MJD | Mag VSTJ044435.43-332755.7 | 04:44:35.432 | -33:27:55.69 | 58222.081 | 21.5 +/- 0.1 VSTJ051111.58-373132.0 | 05:11:11.576 | -37:31:32.04 | 58822.079 | 20.6 +/- 0.1 VSTJ051052.17-335413.9 | 05:10:52.168 | -33:54:13.95 | 58823.140 | 22.2 +/- 0.2 The transients were detected at multiple epochs. Here we report epoch and magnitude for the brightest detection. All the transients appear projected near a galaxy. In particular VSTJ051111.58-373132.0 is located 7.4 arcsec from the nucleus of GLADE131392 which distance is 178Mpc (GLADE catalog). The small distance appears to exclude that this transient is related to the GW event. For the other two galaxies the distance is unknown. In the next days, a fourth observation epoch with the VST is scheduled to check for the transient luminosity evolution. We apologise for any confusion

LIGO/Virgo S191213g: GRAWITA TNG NIR imaging of AT2019wxt (PS19hgw)

We obtained NIR observations of the faint transient AT2019wxt (PS19hgw; McBrien et al., GCN Circ. 26485), possibly associated with the gravitational wave event S191213g (LVC, GCN Circ. 26402), with the 3.58m TNG telescope equipped with NICS in imaging mode. A series of images were obtained with the J filter on 2019-12-18 from 19:16:04 to 19:59:02 UT (i.e. about 5.6 days after the GW event). The transient is clearly detected with a magnitude J(AB) = 19.6 +/- 0.1 (obtained from preliminary psf photometry calibrated against the 2MASS catalogue and subtracting the host galaxy contribution). [GCN OPS NOTE(19dec19): Per author's request, the Circular reference in the first line was changed from 26845 to 26485.

Spectroscopy of the Type Ia supernova 2011fe past 1000d

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 light echo or interaction of the supernova ejecta with surrounding interstellar material. Comparing this extremely late spectrum to an earlier one taken 331 d after the explosion, we find that the most prominent feature at 331 d - [Fe III] emission around 4700 Å - has entirely faded away, suggesting a significant change in the ionization state. Instead, [Fe II] lines are probably responsible for most of the emission at 1034 d. An emission feature at 6300-6400 Å has newly developed at 1034 d, which we tentatively identify with Fe I λ6359, [Fe I] λλ6231, 6394 or [O I] λλ6300, 6364. Interestingly, the features in the 1034 d spectrum seem to be collectively redshifted, a phenomenon that we currently have no convincing explanation for. We discuss the implications of our findings for explosion models, but conclude that sophisticated spectral modelling is required for any firm statement

VizieR Online Data Catalog: SN 2011dh. The first two years (Ergon+, 2015)

All data for the first 100 days (from Paper I, Ergon et al., 2014A&A...562A..17E) and JC UBVRI, SDSS ugriz and 2MASS JHK magnitudes after day 100 and pseudo-bolometric UV-MIR bolometric luminosity before day 400 for SN 2011dh. (4 data files)

VizieR Online Data Catalog: BVRI LCs of type Ib supernova iPTF13bvn (Folatelli+, 2016)

We obtained deep imaging of the field of iPTF13bvn ~740 days after explosion using HST through Cycle 22 programs GO-13684 and GO-13822. Program GO-13684 was executed between 2015 June 26.37 and 26.60 (UT dates are used herein) with the Wide Field Camera 3 (WFC3) UVIS channel. Program GO-13822 comprised observations obtained on 2015 June 30.63 with WFC3/UVIS (F225W filter) and on June 30.90 UT with the Advanced Camera for Surveys (ACS; F814W filter). The supernova (SN) location in the pre- and post-explosion images was found by aligning them relative to a F555W image obtained through program GO-12888 with WFC3/UVIS on 2013 September 2.37 when the SN was still very bright. We also obtained BVRI imaging of iPTF13bvn until ~280 days with the Katzman Automatic Imaging Telescope (KAIT) and the 1m Nickel telescope at Lick Observatory (see table 3). Apparent magnitudes were first measured in the KAIT4 natural system and then transformed to the standard system using local calibrators and color terms as given in Table 4 of Ganeshalingam et al. (2010, J/ApJS/190/418)

Massive stars exploding in a He-rich circumstellar medium - IX. SN 2014av, and characterization of Type Ibn SNe

We present spectroscopic and photometric data of the Type Ibn supernova (SN) 2014av, discovered by the Xingming Observatory Sky Survey. Stringent pre-discovery detection limits indicate that the object was detected for the first time about 4 d after the explosion. A prompt follow-up campaign arranged by amateur astronomers allowed us to monitor the rising phase (lasting 10.6 d) and to accurately estimate the epoch of the maximum light, on 2014 April 23 (JD = 245 6771.1 ± 1.2). The absolute magnitude of the SN at the maximum light is MR = -19.76 ± 0.16. The post-peak light curve shows an initial fast decline lasting about three weeks, and is followed by a slower decline in all bands until the end of the monitoring campaign. The spectra are initially characterized by a hot continuum. Later on, the temperature declines and a number of lines become prominent mostly in emission. In particular, later spectra are dominated by strong and narrow emission features of He I typical of Type Ibn supernovae (SNe), although there is a clear signature of lines from heavier elements (in particular O I, Mg II and Ca II). A forest of relatively narrow Fe II lines is also detected showing P-Cygni profiles, with the absorption component blueshifted by about 1200 km s-1. Another spectral feature often observed in interacting SNe, a strong blue pseudo-continuum, is seen in our latest spectra of SN 2014av. We discuss in this paper the physical parameters of SN 2014av in the context of the Type Ibn SN variety

VizieR Online Data Catalog: PTF12os and iPTF13bvn spectra and light curves (Fremling+, 2016)

Photometric and spectroscopic datasets of PTF12os and iPTF13bvn. Our dataset on PTF12os spans from approximately 8.5 days to 215 days past the SN explosion and it contains optical photometry and spectra. Our data on iPTF13bvn spans from approximately 0.6 to 380 days. The dataset on iPTF13bvn contains optical photometry and optical/infrared spectroscopy. (7 data files)

LIGO/VIRGO G184098 : classifications of transients from the LSQ observations

Classification of the transients LSQ15bbb and LSQ15bbj from the LSQ observations. They are candidates in the G184098 error box