J/A+A/704/A89 Type IIb SN 2024abfo light curves (de Wet+, 2025)
A low mass, binary-stripped envelope for the Type IIb SN 2024abfo.
de Wet S., Leloudas G., Buckley D., Erasmus N., Groot P.J., Zimmerman E.
<Astron. Astrophys. 704, A89 (2025)>
=2025A&A...704A..89D 2025A&A...704A..89D (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry, ultraviolet ; Optical
Keywords: supernovae: general - supernovae: individual: SN 2024abfo
Abstract:
Type IIb supernovae (SNe) are a transitional subclass of
stripped-envelope SNe showing hydrogen lines in their spectra that
gradually weaken and give way to helium lines reminiscent of SNe Ib.
The presence of hydrogen indicates that they retain a non-negligible
hydrogen-rich envelope that has been stripped through stellar winds or
binary interaction. The direct detection of SN progenitors is a
valuable way to connect the various supernova sub-types with their
progenitor stars. SN 2024abfo is the seventh SN IIb with a direct
progenitor detection. Our aim is to study the progenitor candidate and
the supernova itself to determine the evolutionary history of the
system. We astrometrically register our ERIS adaptive optics imaging
with archival HST imaging to determine whether the supernova position
is consistent with the progenitor candidate position. We perform
photometry on archival DECam imaging to derive the spectral energy
distribution of the progenitor candidate and investigate its temporal
variability. We consider single and binary star models to explain the
end point of the progenitor candidate in the Hertzsprung-Russell
diagram. For the supernova we compare the light curves and spectra
with other SNe IIb with progenitor detections. We derive the
bolometric light curve and attempt to fit this with a semi-analytic
light curve model. The position of the supernova in our adaptive
optics imaging agrees with the progenitor position to within 20 mas.
The progenitor SED is consistent with an A3V star with a radius of
∼120 solar radii, a temperature of ∼8800K, and a luminosity of
log(L/L{sun})∼4.9. Single star models predict an initial mass in the
range 12-16 M_sun, while the most probable binary model is a
12+1.2M☉ system with an initial period of 1.73 years. We also
find significant evidence for variability of the progenitor candidate
in the years prior to core-collapse. SN 2024abfo is the least luminous
SN IIb with a direct progenitor detection. At late times the r-band
light curve decays more slowly than the comparison SNe, which may be
due to increased gamma-ray trapping, although this requires further
investigation. Similar to SN 2008ax, SN 2024abfo does not show a
prominent double-peaked light curve. Our semi- analytic light curve
modelling shows that this may be due to a very low mass of hydrogen
<0.006 M_sun in the outer envelope. Spectrally, SN 2024abfo is most
similar to SN 2008ax at early times while at later times (∼80 days) it
appears to show persistent Halpha absorption compared to the
comparison sample. We prefer a binary system to explain SN 2024abfo
and its progenitor, although we are unable to rule out single-star
models. We recommend late-time observations to search for a binary
companion and signatures of CSM-interaction. The absence of these
features would support the hypothesis that SN 2024abfo resulted from a
system which underwent a period of binary mass transfer well before
(>1000∼yr) the explosion, resulting in a low-mass (<0.01M☉)
hydrogen-rich envelope.
Description:
We provide all UV/optical photometry presented in Figure 7 in
photom.dat, and the bolometric+pseudo-bolometric light curve along
with the radius and temperature evolution presented in Figure 9 in
bol_lc.dat.
Objects:
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RA (2000) DE Designation(s)
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03 57 25.62 -46 11 07.6 SN 2024abfo = ATLAS 24qew
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
photom.dat 39 604 UV/optical photometry of SN 2024abfo
bol_lc.dat 87 59 Bolometric and pseudo-bolometric light curve for
SN 2024abfo along with radius and temperature
evolution
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See also:
J/A+A/698/A129 : Photometric measurements of SN 2024abfo (Reguitti+, 2025)
Byte-by-byte Description of file: photom.dat
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Bytes Format Units Label Explanations
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1- 6 F6.2 d Phase [0.02/159.74] Days since explosion
8- 21 A14 --- Tel Telescope/Instrument
23- 26 A4 --- Filt Photometric filter (1)
28 A1 --- l_mag Upper limit flag on mag
29- 33 F5.2 mag mag Observed magnitude in Filter
35- 39 F5.2 mag e_mag ?=99 Magnitude error (2)
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Note (1): filters are UBV, griz, o, uvw1, uvw2 and uvm2.
Note (2): values of 99 correspond to upper limits.
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Byte-by-byte Description of file: bol_lc.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 d Phase [2.49/153.44] Days since explosion
12- 20 F9.3 Rsun R Blackbody radius
22- 30 F9.4 Rsun e_R Blackbody radius error
32- 39 F8.3 K T Blackbody temperature
41- 49 F9.5 K e_T Blackbody temperature error
51- 58 F8.5 [10-7W] logLbol Logarithm of bolometric luminosity
60- 68 F9.7 [10-7W] e_logLbol Logarithm of bolometric luminosity error
70- 77 F8.5 [10-7W] logpLbol Logarithm of pseudo-bolometric luminosity
79- 87 F9.7 [10-7W] e_logpLbol Logarithm of pseudo-bolometric luminosity
error
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Acknowledgements:
Simon de Wet, sndwe(at)dtu.dk
(End) Patricia Vannier [CDS] 03-Nov-2025