SN 2021ckj
RA/DEC (2000)
09:05:51.083 -08:35:07.57
136.46284575 -8.58543675
Type
SN Icn
Redshift
0.143
Related AstroNotes: 2021-71, 2021-76
Reporting Group
ALeRCE
Discovering Data Source
ZTF
Discovery Date
2021-02-09 07:01:53.999
TNS AT
Y
Public
Y
Discovery Mag
19.5725
Filter
g-ZTF
Reporter/s
F. Forster, F.E. Bauer, A. Munoz-Arancibia, L. Hernandez-Garcia, G. Pignata, L. Galbany, G. Pignata, E. Camacho, J. Silva-Farfan, A. Mourao, J. Arredondo, G. Cabrera-Vives, R. Carrasco-Davis, P.A. Estevez, P. Huijse, E. Reyes, I. Reyes, P. Sanchez-Saez, C. Valenzuela, E. Castillo, D. Ruz-Mieres, D. Rodriguez-Mancini, M. Catelan, S. Eyheramendy, M.J. Graham on behalf of the ALeRCE broker

Spectra

 SN_2021ckj - 2021-02-17 02:58:56 VLT-UT1 / FORS2 (adH0cc)z=
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   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),0 (observed)
Spectra
SelectIDObs-date (UT)Tel / InstExp-TimeObserver/sReducer/sGroupSpectrum ascii fileSpectrum fits fileSpec. TypeAssoc. GroupsEnd prop. periodRemarks
89852021-02-17 02:58:56VLT-UT1 / FORS21000serviceA. FloersadH0cc tns_2021ckj_2021-02-17_02-58-56_VLT-UT1_FORS2_adH0cc.asci tns_2021ckj_2021-02-17_02-58-56_VLT-UT1_FORS2_adH0cc.fitsObjectadH0ccQuick-reduction spectrum, telluric corrections applied.
Light Curves
FilterTel / InstObs-date rangePhotometry
cyan-ATLASATLAS1_ACAM12021-02-11 09:20:10 - 2021-02-13 10:37:552
Photometry
IDObs-dateMag. / FluxErrLim. Mag./FluxUnitsFilterTel / InstExp-timeObserver/sRemarks
1926482021-02-13 10:37:5519.2970.14219.63ABMagcyan-ATLASATLAS1_ACAM130Robot
1926472021-02-11 09:20:1019.76ABMagcyan-ATLASATLAS1_ACAM130Robot[Last non detection]
g-ZTFP48_ZTF-Cam2021-02-07 08:39:41 - 2021-02-09 07:01:542
Photometry
IDObs-dateMag. / FluxErrLim. Mag./FluxUnitsFilterTel / InstExp-timeObserver/sRemarks
1914002021-02-09 07:01:5419.57250.11011820.8224ABMagg-ZTFP48_ZTF-Cam30RobotData provided by ZTF
1913992021-02-07 08:39:4120.7271ABMagg-ZTFP48_ZTF-Cam30Robot[Last non detection] Data provided by ZTF
r-ZTFP48_ZTF-Cam2021-02-09 09:03:04 - 2021-02-09 09:03:041
Photometry
IDObs-dateMag. / FluxErrLim. Mag./FluxUnitsFilterTel / InstExp-timeObserver/sRemarks
1914012021-02-09 09:03:0419.95090.138920.5993ABMagr-ZTFP48_ZTF-Cam30RobotData provided by ZTF
AT Reports
IDTime received (UT)SenderReporter/sReportting groupDisc. Data SourceRADECDiscovery date (UT)Discovery Mag.FilterRelated filesAT TypeInternal nameAssoc. GroupsEnd prop. periodRemarks
994732021-02-14 21:26:37ATLAS_Bot1J. Tonry, L. Denneau, A. Heinze, H. Weiland (IfA, University of Hawaii), B. Stalder (LSST), A. Rest (STScI), C. Stubbs (Harvard University), K. W. Smith, S. J. Smartt, D. R. Young, S. Srivastav, O. McBrien, M. Fulton, J. Gillanders, C. Webb (Queen's University Belfast), T.-W. Chen (MPE), D. E. Wright (University of Minnesota), J. Anderson (ESO)ATLASATLAS09:05:51.079-08:35:07.612021-02-13 10:37:55.20019.297cyan-ATLASPSNATLAS21fruATLAS
989232021-02-09 19:25:21ALeRCEF. Forster, F.E. Bauer, A. Munoz-Arancibia, L. Hernandez-Garcia, G. Pignata, L. Galbany, G. Pignata, E. Camacho, J. Silva-Farfan, A. Mourao, J. Arredondo, G. Cabrera-Vives, R. Carrasco-Davis, P.A. Estevez, P. Huijse, E. Reyes, I. Reyes, P. Sanchez-Saez, C. Valenzuela, E. Castillo, D. Ruz-Mieres, D. Rodriguez-Mancini, M. Catelan, S. Eyheramendy, M.J. Graham on behalf of the ALeRCE brokerALeRCEZTF09:05:51.083-08:35:07.572021-02-09 07:01:53.99919.5725g-ZTFPSNZTF21aajbgolZTFEarly SN candidate (g-rise > 0.60+-0.06 mag/day, r-rise > 0.29+-0.07 mag/day) classified using ALeRCE's stamp classifier - see http://arxiv.org/abs/2008.03309 - and the public ZTF stream. Discovery image and light curve in http://alerce.online/object/ZTF21aajbgol
Classification Reports
IDTime received (UT)SenderClassifier/sGroupClassificationRedshiftRelated filesAssoc. GroupsEnd prop. periodRemarksADS Bibcode
89752021-02-18 20:55:51taubenA. Pastorello (INAF Padova), C. Vogl, S. Taubenberger, A. Floers, G. Csoernyei, M. G. Cudmani, A. Holas, W. Hillebrandt, S. H. Suyu (MPA Garching), S. Blondin (CNRS, LAM), B. Leibundgut, J. Spyromilio (ESO), S. J. Smartt, M. Dobson (QUB), R. Kotak (Turku), R. Bruch, A. Gal-Yam (Weizmann), C. Lemon (Lausanne)adH0ccSN Icn0.143adH0ccAn optical spectrum of SN 2021ckj, obtained on 2021 February 16 with the ESO Very Large Telescope UT1, the FORS2 spectrograph, and grism 300V, shows a blue continuum with a blackbody temperature of about 10000 K. The continuum is undulated by several broad (v > 10000 km/s) spectral lines, especially in the restframe range between 3500 and 5500 Å, reminiscent of SLSNe-I. Superimposed on this spectrum, one can find a series of narrow to intermediate-width lines (v = 1000 to 2500 km/s), some of them in emission, others exhibiting P-Cygni profiles. The lines can mostly be attributed to carbon: C III at 4650 Å and 5696 Å, and C II at 4267 Å, 5891 Å, 6580 Å and 7234 Å. He I 5875 Å is also detected. The redshift of the supernova of z = 0.143 has been measured from these narrow lines. A phase of 10d from explosion has been estimated from the combined ZTF and ATLAS light curves. With a rise time of merely a few days and a peak absolute g-band magnitude close to -20, SN 2021ckj is photometrically a fast blue optical transient (FBOT). Spectroscopically, it would be best characterised as a "Type Icn" supernova. Similarities with AT 2021csp (Perley et al., AstroNote 2021-62) should be investigated.2021TNSCR.511....1P

Comments

Following the reporters' request, with the introduction of the new Icn classification.