J/ApJ/954/35 H-poor type IIb SN 2020bio LCs & spectra (Pellegrino+, 2023)
SN 2020bio: a double-peaked, H-poor type IIb supernova with evidence of
circumstellar interaction.
Pellegrino C., Hiramatsu D., Arcavi I., Howell D.A., Bostroem K.A.,
Brown P.J., Burke J., Elias-Rosa N., Itagaki K., Kaneda H., McCully C.,
Modjaz M., Gonzalez E.P., Pritchard T.A., Yesmin N.
<Astrophys. J., 954, 35 (2023)>
=2023ApJ...954...35P 2023ApJ...954...35P
ADC_Keywords: Supernovae; Photometry, ultraviolet; Photometry, ugriz;
Spectra, optical
Keywords: Circumstellar matter ; Core-collapse supernovae ; Supernovae
Abstract:
We present photometric and spectroscopic observations of SN 2020bio, a
double-peaked Type IIb supernova (SN) discovered within a day of
explosion, primarily obtained by Las Cumbres Observatory and Swift.
SN2020bio displays a rapid and long-lasting initial decline throughout
the first week of its light curve, similarly to other well-studied
Type IIb SNe. This early-time emission is thought to originate from
the cooling of the extended outer hydrogen-rich (H-rich) envelope of
the progenitor star that is shock heated by the SN explosion. We
compare SN 2020bio to a sample of other double-peaked Type IIb SNe in
order to investigate its progenitor properties. Analytical model fits
to the early-time emission give progenitor radius (∼100-1500R☉)
and H-rich envelope mass (∼0.01-0.5M☉) estimates that are
consistent with other Type IIb SNe. However, SN 2020bio displays
several peculiarities, including (1) weak H spectral features
indicating a greater amount of mass loss than other Type IIb
progenitors; (2) an underluminous secondary light-curve peak that
implies a small amount of synthesized 56Ni (MNi∼0.02M☉); and
(3) low-luminosity nebular [OI] and interaction-powered nebular
features. These observations are more consistent with a lower-mass
progenitor (MZAMS∼12M☉) that was stripped of most of its
H-rich envelope before exploding. This study adds to the growing
diversity in the observed properties of Type IIb SNe and their
progenitors.
Description:
SN 2020bio was discovered by Koichi Itagaki on UT 2020 January 29.77
at the Itagaki Astronomical Observatory at an unfiltered Vega
magnitude of 16.7.
Soon after discovery, rapid photometric and spectroscopic follow-up
observations were requested by the Global Supernova Project (GSP)
through the Las Cumbres global network of telescopes. The GSP also
triggered its Swift Key Project (1518618: PI Howell) to obtain daily
UV and optical photometry. A classification spectrum obtained on the
2.0m Liverpool Telescope (LT) on 2020 January 31.19 --approximately
1.5 days after the first detection-- shows a blue continuum
superimposed with a narrow Hα emission feature and a broad
possible HeIλ5876Å feature, consistent with a young
core-collapse SN.
UBgVri-band images were obtained by the Sinistro and Spectral cameras
mounted on LCO 1.0 and 2.0m telescopes, respectively, located at
McDonald Observatory, Teide Observatory, and Haleakala Observatory.
We also obtained Asteroid Terrestrial-impact Last Alert System (ATLAS)
forced photometry.
UV and optical photometry were obtained with the Ultraviolet and
Optical Telescope (UVOT) on the Neil Gehrels Swift observatory.
LCO spectra were obtained by the FLOYDS spectrograph on the 2.0m
Faulkes Telescope North at Haleakala Observatory. Spectra cover a
wavelength range of 3500-10000Å at a resolution R∼300-600.
We also present one spectrum obtained by the B and C spectrograph on
the 2.3m Bok Telescope at Steward Observatory, two spectra obtained
by the Blue Channel Spectrograph on the 6.5m MMT at the Fred Lawrence
Whipple Observatory, and one spectrum obtained by the Optical System
for Imaging and low/intermediate-Resolution Integrated Spectroscopy
(OSIRIS) spectrograph on the 10.4m Gran Telescopio Canarias.
Objects:
----------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------
13 55 37.68 +40 28 39.1 SN 2020bio = AT 2020bio
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 35 264 UV and optical photometry
table2.dat 108 12 Log of spectroscopic observations
sp/* . 12 Spectra in ASCII format; downloaded from WISeREP
(2012PASP..124..668Y 2012PASP..124..668Y - https://www.wiserep.org)
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See also:
II/183 : UBVRI Photometric Standards (Landolt 1992)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
VIII/77 : HI spectral properties of galaxies (Springob+, 2005)
J/ApJ/702/226 : Swift/UVOT panchromatic obs. of SN 2008D (Modjaz+, 2009)
J/ApJ/742/L18 : Follow-up photometry of the SN IIb PTF 11eon (Arcavi+, 2011)
J/A+A/562/A17 : SN 2011dh - The first 100 days (Ergon+, 2014)
J/ApJ/789/104 : SNe IIn observations and properties (Ofek+, 2014)
J/A+A/573/A12 : SN1993J sp. 100-500 days post-explosion (Jerkstrand+, 2015)
J/ApJ/827/90 : Spectroscopy of SNe Ib, IIb and Ic (Liu+, 2016)
J/MNRAS/459/3939 : Type II supernova light curves (Valenti+, 2016)
J/ApJ/883/147 : UV-NIR LCs of the H-stripped SN2016coi (Terreran+, 2019)
J/ApJ/898/166 : UV to NIR obs. of SN 2019ehk (Jacobson-Galan+, 2020)
J/ApJ/900/46 : UV, opt. & IR light curve of SN2019dge (Yao+, 2020)
J/ApJ/912/46 : ZTF Type II supernovae with follow-up obs. (Bruch+, 2021)
J/ApJ/907/99 : Pre-explosion LC of 227 Supernovae (Strotjohann+, 2021)
J/ApJ/932/58 : LCs & sp. of SNe 2021gno & 2021inl (Jacobson-Galan+, 2022)
http://www.wiserep.org/ : WISeREP homepage
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.2 d JD Julian Date of Observation
12- 16 A5 --- Filt Filter
18- 22 F5.2 mag mag [13.46/20.92] Magnitude in Filt;
either AB or Vega (1)
24- 27 F4.2 mag e_mag [0.01/0.3] Uncertainty in mag
29- 35 A7 --- Tel Source/Telescope (2)
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Note (1): Magnitudes given in Vega or AB systems as:
ATLAS = AB;
Itagaki = calibrated to the V-band magnitudes of 45 field stars
from the Fourth US Naval Observatory CCD Astrograph Catalog;
LCO (UBV) = Vega;
LCO (gri) = AB;
Swift = Vega.
Note (2): Telescope as follows:
LCO = the Las Cumbres Observatory (198 occurrences)
ATLAS = the Asteroid Terrestrial-impact Last Alert System (47 occurrences)
Swift = the Neil Gehrels Swift observatory (11 occurrences)
Itagaki = the Itagaki Astronomical Observatory (8 occurrences)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 "datime" Date Date of observation (UT)
21- 23 I3 --- Days [1/201] Days since discovery
25- 40 A16 --- Inst Facility/Instrument
42- 45 I4 s Exp [300/3600] Exposure time
47- 50 I4 0.1nm lam1 [3500/5700] Lower range of wavelength
51 A1 --- --- [-]
52- 56 I5 0.1nm lam2 [7000/10000] Upper range of Wavelength
58-108 A51 --- File File name of the spectra in subdirectory "sp";
column added by CDS
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History:
From electronic version of the journal for the tables
* spectra downloaded on WISeREP at: http://www.wiserep.org/object/14046
Acknowledgements:
WISeREP (2012PASP..124..668Y 2012PASP..124..668Y) -- http://www.wiserep.org
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Nov-2025