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arxiv: 2605.06313 · v1 · submitted 2026-05-07 · 🌌 astro-ph.HE · astro-ph.SR

Recognition: unknown

Early interaction signatures and an extended plateau phase in Type II SN 2020aze

B. Ailawadhi, C. Inserra, C. McCully, C. Pellegrino, D. A. Howell, D. E. Reichart, D. Hiramatsu, D. Janzen, D. J. Sand, D. R. Young, E. Padilla Gonzalez, G. Pignata, J. E. Andrews, J. Haislip, J. P. Anderson, J. Sollerman, K. A. Bostroem, K. Misra, L. Yadav, M. Gromadzki, N. Dukiya, P. J. Brown, R. Cartier, R. Dastidar, S. Valenti, S. W. Jha, T. E. M\"uller-Bravo, T. W. Chen, V. Kouprianov, Y. Dong

Pith reviewed 2026-05-08 06:06 UTC · model grok-4.3

classification 🌌 astro-ph.HE astro-ph.SR
keywords Type II supernovaSN 2020azecircumstellar materialHe II emissionred supergiantejecta interactionlight curve modelingplateau phase
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The pith

Type II SN 2020aze displays early He II 4686 lines from ejecta interacting with dense circumstellar material and an extended plateau consistent with a 14 solar mass red supergiant.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents photometry and spectroscopy of the fast-declining Type II supernova 2020aze from 2 to 137 days after explosion. Early spectra before day 6 show a narrow emission line at 4687 Angstroms and a broader feature from 4400 to 4800 Angstroms, which the authors attribute to narrow and blue-shifted broad He II 4686 emission produced when the ejecta hit dense circumstellar material. Light-curve modeling yields an initial radius near 1100 solar radii, ejecta mass of 12 solar masses, explosion energy of 1.5 times 10 to the 51st erg, and a red supergiant progenitor of about 14 solar masses with a mass-loss rate around 10 to the minus 3 solar masses per year. If correct, these findings illustrate how pre-explosion mass loss and circumstellar interaction can produce both rapid early decline and a prolonged recombination phase in Type II events.

Core claim

SN 2020aze exhibits transient narrow and broad blue-shifted He II 4686 features in spectra younger than 6 days, taken as direct evidence of ejecta interaction with dense circumstellar material, while semi-analytical modeling of its light curve gives an initial radius of 1100 solar radii, ejecta mass 12 solar masses, explosion energy 1.5e51 erg, and a red supergiant progenitor mass of 14 solar masses with a weak wind of 10^{-3} solar masses per year; the combination of early interaction signatures, steep decline, and extended photospheric phase demonstrates the influence of pre-supernova mass loss on Type II supernova diversity.

What carries the argument

Transient narrow 4687 Angstrom emission and 4400-4800 Angstrom broad feature interpreted as narrow and blue-shifted broad He II 4686 from ejecta-dense CSM interaction, together with semi-analytical light-curve models used to extract progenitor radius, mass, and energy.

If this is right

  • The 2.04 mag per 100 days decline and 120-day recombination phase arise because circumstellar interaction modifies the standard recombination-driven plateau.
  • A mass-loss rate near 10^{-3} solar masses per year is required to produce the observed early interaction signatures in a red supergiant wind.
  • Fast-declining Type II events can still host extended plateaus when pre-explosion mass loss creates sufficient circumstellar density.
  • Early-time spectroscopy within the first few days is necessary to catch transient He II features before they fade.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Many fast-declining Type II supernovae may harbor undetected early interaction phases if they lack spectra before day 6.
  • The extended plateau implies that circumstellar material can lengthen the photospheric phase even in events that initially appear to decline steeply.
  • Similar transient He II detections in future rapid-follow-up observations would allow systematic mapping of circumstellar densities around Type II progenitors.

Load-bearing premise

The spectral features at 4687 Angstroms and across 4400-4800 Angstroms must be produced by He II 4686 from ejecta hitting circumstellar material rather than by other ions or non-interaction processes.

What would settle it

High-resolution spectra or detailed non-LTE modeling that identifies the 4687 Angstrom line as a different species or shows that standard non-interacting Type II models fit the early spectra without requiring circumstellar material.

Figures

Figures reproduced from arXiv: 2605.06313 by B. Ailawadhi, C. Inserra, C. McCully, C. Pellegrino, D. A. Howell, D. E. Reichart, D. Hiramatsu, D. Janzen, D. J. Sand, D. R. Young, E. Padilla Gonzalez, G. Pignata, J. E. Andrews, J. Haislip, J. P. Anderson, J. Sollerman, K. A. Bostroem, K. Misra, L. Yadav, M. Gromadzki, N. Dukiya, P. J. Brown, R. Cartier, R. Dastidar, S. Valenti, S. W. Jha, T. E. M\"uller-Bravo, T. W. Chen, V. Kouprianov, Y. Dong.

Figure 1
Figure 1. Figure 1: A 120-second 𝑟-band image of the host galaxy NGC 3318, taken with the 1-m LCO telescope on MJD 58876.9, showing the positions of SN 2020aze along with two previous SNe 2000cl and 2017ahn. It is along the north-East direction view at source ↗
Figure 2
Figure 2. Figure 2: DLT40 Clear-band light curve of SN 2017ahn is matched to that of SN 2020aze during the rising phase. The x-axis denotes the days since the explosion for SN 2017ahn. The best fit to the rising light curve (up to 6 days post-discovery) is used to constrain the explosion epoch of SN 2020aze more precisely as compared to the shallow DLT40 non-detection limits prior to discovery (inverted triangle). program wit… view at source ↗
Figure 3
Figure 3. Figure 3: Multi-component Gaussian fits to the distinct D2 and D1 features of the Na i profile in the 2.6 day spectrum of SN 2020aze. curves show a rise to maximum brightness, followed by a linearly declining photospheric phase, and a subsequent drop marking the end of the photospheric phase. There are limited observations during the fall and no observations during the radioactive tail phase of SN 2020aze as it went… view at source ↗
Figure 4
Figure 4. Figure 4: The multi-band light curves of SN 2020aze from 2.2 to 137.4 days since the explosion are shown. The red solid line marks the decline of the 𝑉-band light curve during the plateau phase (s2), while the downward arrows indicate non-detections reported by the DLT40 survey. 60 80 100 120 140 160 tpt (days) 5 10 15 20 25 30 35 tpt - O P T d (d a y s) 15.2 ± 6.4 24.6 ± 8.1 2020aze Normal Type IIP SNe Long Plateau SNe view at source ↗
Figure 5
Figure 5. Figure 5: The scatter plot of 𝑡pt - OPTd vs. 𝑡pt for Type II SNe is shown. SNe with plateau durations shorter than 120 days are marked in blue, while those with durations longer than 120 days are marked in orange, and SN 2020aze is highlighted in grey. The horizontal lines represent the median value of 𝑡pt - OPTd, and errors correspond to 1𝜎 of the distribution. of ∼0.04 M⊙, based on the bolometric correction method… view at source ↗
Figure 6
Figure 6. Figure 6: Comparison of the 𝑉-band absolute magnitude light curve of SN 2020aze with other Type II SNe. The grey light curves represent the 116 Type II SNe with varying photospheric phase durations taken from Anderson et al. (2014). all the SNe studied. As the recombination phase begins, the colour becomes progressively redder due to the expansion and cooling of the SN ejecta. Notably, during the recombination phase… view at source ↗
Figure 8
Figure 8. Figure 8: Comparison of (𝐵 − 𝑉) colour evolution of SN 2020aze with other Type II SNe. Grey lines in the background represent the sample from de Jaeger et al. (2018). 4 LIGHT CURVE MODELLING 4.1 Early Light Curve Modelling SN explosions occur with a short flash of high-energy radiation followed by optical/NIR emission from the expanding layers of SN ejecta. The early-phase light curve analysis of CCSNe aids in estim… view at source ↗
Figure 10
Figure 10. Figure 10: Evolution of the bolometric light curve of SN 2020aze is plot￾ted along with 45 best fitted MCMC light curves using the semi-analytical modelling prescription of Nagy & Vinkó (2016) and Jäger et al. (2020). 4.2 Bolometric light curve modelling We performed semi-analytical modelling of the bolometric light curve to obtain estimates of the SN explosion parameters such as the initial ejecta radius (R0), ejec… view at source ↗
Figure 11
Figure 11. Figure 11: Spectral evolution of SN 2020aze from 2.6 to 322.0 days since the explosion, with the identified lines shown in the upper panel. The spectra are corrected for redshift and extinction. The actual spectra (grey) are smoothed (black) for line identification. The lower panel displays the best-fit models from SYNAPPS for the spectra at 31.7 days. The spectral features identified through the modelling are also … view at source ↗
Figure 12
Figure 12. Figure 12: Comparison of the SN 2020aze spectrum with other Type II SNe at 31.7 day. The H𝛼 line profile in velocity space along the x-axis is also indicated. (Pessi et al. 2024), these typically exhibit velocities around ∼1,000 km s−1 and cannot explain the extreme velocities observed in the case of SN 2020aze. The most plausible explanation for the ledge-like feature in SN 2020aze is blue-shifted He ii 𝜆4686, prod… view at source ↗
Figure 16
Figure 16. Figure 16: Comparison of the 30 day deredshifted and reddening corrected spectrum of SN 2020aze with the model spectra of Dessart et al. (2014) at different metallicities. distinct subclasses–ECSNe and LLEV SNe. We outline below the characteristic features of these atypical explosions and assess how the properties of SN 2020aze align with or diverge from them. ECSNe are considered a subclass of SNe, expected to exhi… view at source ↗
Figure 15
Figure 15. Figure 15: Velocity evolution of SN 2020aze and comparison with other SNe. The mean velocities of the Type II SNe sample from Gutiérrez et al. (2017) are indicated by a blue solid line, while the grey band represents the corresponding standard deviations. 4000 5000 6000 7000 8000 9000 Rest Wavelength (Å) N orm alis e d F + c o n s t 0.1Z 0.4Z 1.0Z 2.0Z SN 2020aze FeII view at source ↗
read the original abstract

We present a photometric and spectroscopic analysis of the fast-declining Type II SN 2020aze, observed in optical bands from 2.2 to 137.4 days after explosion. The V-band light curve reaches a peak absolute magnitude of about minus 16.97$\pm$0.20 mag by 15 days, followed by a recombination phase with a decline rate of 2.04$\pm$0.13 mag per 100 days, lasting about 120 days. Early spectra (younger than 6 days) show a transient weak narrow emission line at 4687 Angstroms and a feature spanning 4400-4800 Angstroms, attributed to narrow and broad blue-shifted He II 4686, indicating interaction between the ejecta and dense circumstellar material. Comparison with spectral models suggests a red supergiant progenitor with a weak wind and a mass-loss rate of about 1e-3 solar masses per year. Semi-analytical light-curve modeling gives an initial radius of about 1100 solar radii, an ejecta mass of about 12 solar masses, an explosion energy of about 1.5e51 erg, and a progenitor mass of about 14 solar masses. These early interaction signatures, the steep decline, and the extended photospheric phase highlight the role of pre-supernova mass loss and circumstellar interaction in shaping the diversity of Type II supernovae.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The manuscript presents photometric and spectroscopic observations of the fast-declining Type II supernova SN 2020aze from 2.2 to 137.4 days post-explosion. It identifies transient narrow emission at 4687 Å and a 4400-4800 Å feature in spectra younger than 6 days as narrow and broad blue-shifted He II 4686, interpreted as evidence of early ejecta-CSM interaction. Semi-analytical light-curve modeling is used to derive an initial radius of ~1100 R_⊙, ejecta mass ~12 M_⊙, explosion energy ~1.5×10^51 erg, and progenitor mass ~14 M_⊙, with a mass-loss rate ~10^{-3} M_⊙ yr^{-1} from spectral comparisons; the work emphasizes the role of pre-supernova mass loss in shaping Type II diversity.

Significance. If the He II identification holds and the light-curve parameters can be shown to be robust despite the claimed interaction, the result would add a well-observed case of early CSM interaction in a Type II event with an extended plateau, helping quantify how mass-loss episodes affect light-curve morphology. The combination of early spectra and long-term photometry is a strength.

major comments (3)
  1. [light-curve modeling results] The semi-analytical light-curve modeling (described in the results section following the spectral analysis) employs standard diffusion-based codes that assume a homologously expanding sphere with no additional energy input from shock-CSM interaction. This assumption is violated by the early spectra claiming ejecta-CSM interaction that would contribute extra luminosity to the first ~15 days of photometry used in the fit, rendering the reported R_init, M_ej, and E unreliable without re-fitting using an interacting-SN module.
  2. [early spectra analysis] The attribution of the 4687 Å line and 4400-4800 Å feature specifically to He II 4686 (narrow and broad components) lacks quantitative support such as velocity measurements, line-profile decomposition, or direct comparison to synthetic spectra with goodness-of-fit metrics; the transient and weak nature of the features makes the identification load-bearing for the interaction claim but currently under-constrained.
  3. [abstract and results] No uncertainties, error budgets, data-exclusion criteria, or quantitative fit statistics (e.g., reduced χ²) are reported for the derived parameters or the semi-analytical fits, so the central numerical claims (R_init ≈ 1100 R_⊙, M_ej ≈ 12 M_⊙, etc.) cannot be assessed for robustness.
minor comments (2)
  1. [photometric analysis] The V-band decline rate is stated as 2.04±0.13 mag per 100 days; clarify whether this is measured over the full 120-day plateau or a specific interval and how the uncertainty was derived.
  2. [throughout] Notation for solar units (R_⊙, M_⊙) and scientific notation for energy should be standardized throughout the text and figures.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the careful and constructive review of our manuscript on SN 2020aze. We address each major comment in turn below, indicating where revisions will be made to strengthen the presentation and analysis.

read point-by-point responses

  1. Referee: [light-curve modeling results] The semi-analytical light-curve modeling (described in the results section following the spectral analysis) employs standard diffusion-based codes that assume a homologously expanding sphere with no additional energy input from shock-CSM interaction. This assumption is violated by the early spectra claiming ejecta-CSM interaction that would contribute extra luminosity to the first ~15 days of photometry used in the fit, rendering the reported R_init, M_ej, and E unreliable without re-fitting using an interacting-SN module.

    Authors: We agree that the semi-analytical models employed do not incorporate explicit energy input from ejecta-CSM interaction. The early interaction signatures are indeed present and could contribute additional luminosity during the rise. To address this, we will re-perform the light-curve modeling by excluding the first 15 days of photometry (where interaction effects are strongest) and compare the resulting parameters to the original fit. If an interacting SN module is accessible, we will also test it; otherwise, we will explicitly discuss the limitation and the robustness of the plateau-phase constraints on M_ej and E. These changes will be incorporated in the revised manuscript. revision: yes

  2. Referee: [early spectra analysis] The attribution of the 4687 Å line and 4400-4800 Å feature specifically to He II 4686 (narrow and broad components) lacks quantitative support such as velocity measurements, line-profile decomposition, or direct comparison to synthetic spectra with goodness-of-fit metrics; the transient and weak nature of the features makes the identification load-bearing for the interaction claim but currently under-constrained.

    Authors: The line identification rests on the precise wavelength coincidence with He II 4686, the transient appearance only in spectra younger than 6 days, and analogy to other early-interacting Type II events. We will expand the spectral analysis section to include measured velocities (narrow component near rest, broad component blueshifted), a description of the line profile, and direct overlays of the observed features against published synthetic spectra or model predictions used for the mass-loss rate estimate. While a full chi-squared minimization against synthetic spectra is not feasible given the low signal-to-noise of the weak features, the added quantitative details and literature comparisons will better substantiate the claim. revision: partial

  3. Referee: [abstract and results] No uncertainties, error budgets, data-exclusion criteria, or quantitative fit statistics (e.g., reduced χ²) are reported for the derived parameters or the semi-analytical fits, so the central numerical claims (R_init ≈ 1100 R_⊙, M_ej ≈ 12 M_⊙, etc.) cannot be assessed for robustness.

    Authors: We acknowledge that uncertainties, fit statistics, and data-handling details were omitted. In the revised manuscript we will report formal uncertainties on all derived quantities (R_init, M_ej, E, progenitor mass), include the reduced χ² values for the semi-analytical fits, specify any photometric points excluded from the modeling, and add a brief error-budget discussion. These additions will allow readers to evaluate the robustness of the reported parameters. revision: yes

Circularity Check

0 steps flagged

No significant circularity; parameters are standard model fits to photometry

full rationale

The paper's derivation chain separates spectral identification of possible He II features (attributed to early ejecta-CSM interaction) from semi-analytical light-curve modeling that yields R_init, M_ej, E, and progenitor mass. These quantities are presented as direct outputs of fitting the observed photometry under standard diffusion assumptions, with no claim that they are independent first-principles predictions or that the spectral data are used to derive the same parameters by construction. No self-citations, uniqueness theorems, or ansatzes are invoked as load-bearing steps that reduce the central results to tautologies. The chain remains self-contained against the two distinct observational inputs (spectra and light curve).

Axiom & Free-Parameter Ledger

5 free parameters · 2 axioms · 0 invented entities

The central claims rest on five fitted parameters obtained from light-curve modeling and on domain assumptions about the identification of spectral lines and the applicability of the chosen semi-analytical models.

free parameters (5)
  • mass-loss rate = 10^{-3} M_sun yr^{-1}
    Estimated from comparison with spectral models for the progenitor wind
  • initial radius = 1100 R_sun
    Obtained from semi-analytical light-curve modeling
  • ejecta mass = 12 M_sun
    Obtained from semi-analytical light-curve modeling
  • explosion energy = 1.5e51 erg
    Obtained from semi-analytical light-curve modeling
  • progenitor mass = 14 M_sun
    Obtained from semi-analytical light-curve modeling
axioms (2)
  • domain assumption The 4687 Angstrom narrow line and 4400-4800 Angstrom feature arise from narrow and broad blue-shifted He II 4686 produced by ejecta-CSM interaction
    Central attribution used to infer circumstellar interaction; invoked in the abstract description of early spectra
  • domain assumption Semi-analytical light-curve models for Type II supernovae with weak winds accurately recover physical parameters when fitted to the observed photometry
    Required to translate the light-curve shape into the quoted radius, masses, and energy

pith-pipeline@v0.9.0 · 5732 in / 1979 out tokens · 87217 ms · 2026-05-08T06:06:42.017828+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

124 extracted references · 110 canonical work pages

  1. [1]

    , keywords =

    Electron scattering wings on lines in interacting supernovae. , keywords =. doi:10.1093/mnras/stx3163 , archivePrefix =. 1712.01237 , primaryClass =

    work page doi:10.1093/mnras/stx3163

  2. [2]

    Evolved Massive Stars in the Local Group. I. Identification of Red Supergiants in NGC 6822, M31, and M33. , keywords =. doi:10.1086/305818 , adsurl =

    work page doi:10.1086/305818

  3. [3]

    The Evolution of Massive Stars. I. Red Supergiants in the Magellanic Clouds. , keywords =. doi:10.1086/379558 , archivePrefix =. astro-ph/0309272 , primaryClass =

    work page doi:10.1086/379558

  4. [4]

    , keywords =

    The Red Supergiant Binary Fraction of the Large Magellanic Cloud. , keywords =. doi:10.3847/1538-4357/ababaa , archivePrefix =. 2007.15852 , primaryClass =

    work page doi:10.3847/1538-4357/ababaa 2007

  5. [5]

    C., Rossi, E

    SN 1994W: an interacting supernova or two interacting shells?. , keywords =. doi:10.1111/j.1365-2966.2008.14042.x , archivePrefix =. 0804.0428 , primaryClass =

    work page doi:10.1111/j.1365-2966.2008.14042.x 2008

  6. [6]

    , keywords =

    Broad emission lines from the opaque electron-scattering environment of SN 1998S. , keywords =. doi:10.1111/j.1365-2966.2001.04717.x , archivePrefix =. astro-ph/0106234 , primaryClass =

    work page doi:10.1111/j.1365-2966.2001.04717.x 2001

  7. [7]

    Nuovo Cimento C Geophysics Space Physics C , keywords =

    PROMPT: Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes. Nuovo Cimento C Geophysics Space Physics C , keywords =. doi:10.1393/ncc/i2005-10149-6 , archivePrefix =. astro-ph/0502429 , primaryClass =

    work page doi:10.1393/ncc/i2005-10149-6

  8. [8]

    A., Stritzinger, M

    The diversity of Type II supernova versus the similarity in their progenitors. , keywords =. doi:10.1093/mnras/stw870 , archivePrefix =. 1603.08953 , primaryClass =

    work page doi:10.1093/mnras/stw870

  9. [9]

    2014, MNRAS, 438, L101, doi: 10.1093/mnrasl/slt171

    The first month of evolution of the slow-rising Type IIP SN 2013ej in M74 ^ ★. , keywords =. doi:10.1093/mnrasl/slt171 , archivePrefix =. 1309.4269 , primaryClass =

    work page doi:10.1093/mnrasl/slt171

  10. [10]

    CHARACTERIZING THE<i>V</i>-BAND LIGHT-CURVES OF HYDROGEN-RICH TYPE II SUPERNOVAE

    Characterizing the V-band Light-curves of Hydrogen-rich Type II Supernovae. , keywords =. doi:10.1088/0004-637X/786/1/67 , archivePrefix =. 1403.7091 , primaryClass =

    work page doi:10.1088/0004-637x/786/1/67

  11. [11]

    , keywords =

    Photometric properties of type II supernovae. , keywords =

  12. [12]

    , keywords =

    Photometric Behavior of Evolved Supernovae. , keywords =. doi:10.1086/115558 , adsurl =

    work page doi:10.1086/115558

  13. [13]

    , keywords =

    A sample of Type II-L supernovae. , keywords =. doi:10.1093/mnras/stu1760 , archivePrefix =. 1409.1536 , primaryClass =

    work page doi:10.1093/mnras/stu1760

  14. [14]

    , keywords =

    ASASSN-14dq: a fast-declining Type II-P supernova in a low-luminosity host galaxy. , keywords =. doi:10.1093/mnras/sty1957 , archivePrefix =. 1807.07251 , primaryClass =

    work page doi:10.1093/mnras/sty1957

  15. [15]

    Research Notes of the American Astronomical Society , year = 2018, month = dec, volume =

    SuperBol: A User-friendly Python Routine for Bolometric Light Curves. Research Notes of the American Astronomical Society , year = 2018, month = dec, volume =. doi:10.3847/2515-5172/aaf799 , adsurl =

    work page doi:10.3847/2515-5172/aaf799 2018

  16. [16]

    , keywords =

    Supernova 2013by: a Type IIL supernova with a IIP-like light-curve drop ^ ★. , keywords =. doi:10.1093/mnras/stv208 , archivePrefix =. 1501.06491 , primaryClass =

    work page doi:10.1093/mnras/stv208

  17. [17]

    , keywords =

    The long-lived Type IIn SN 2015da: Infrared echoes and strong interaction within an extended massive shell. , keywords =. doi:10.1051/0004-6361/201936553 , archivePrefix =. 1908.08580 , primaryClass =

    work page doi:10.1051/0004-6361/201936553 1908

  18. [18]

    , year = 2000, month = may, volume =

    Supernova 2000cl in NGC 3318. , year = 2000, month = may, volume =

    2000

  19. [19]

    , keywords =

    The Early Discovery of SN 2017ahn: Signatures of Persistent Interaction in a Fast-declining Type II Supernova. , keywords =. doi:10.3847/1538-4357/abca8a , archivePrefix =. 2008.06515 , primaryClass =

    work page doi:10.3847/1538-4357/abca8a 2008

  20. [20]

    , keywords =

    Weak Mass Loss from the Red Supergiant Progenitor of the Type II SN 2021yja. , keywords =. doi:10.3847/1538-4357/ac75f0 , archivePrefix =. 2203.08155 , primaryClass =

    work page doi:10.3847/1538-4357/ac75f0

  21. [21]

    , keywords =

    Shock Cooling and Possible Precursor Emission in the Early Light Curve of the Type II SN 2023ixf. , keywords =. doi:10.3847/2041-8213/ace4c4 , archivePrefix =. 2306.06097 , primaryClass =

    work page doi:10.3847/2041-8213/ace4c4 2041

  22. [22]

    arXiv e-prints , keywords =

    Circumstellar Medium Interaction in SN 2018lab, A Low-Luminosity II-P Supernova observed with TESS. arXiv e-prints , keywords =

  23. [23]

    FLASH SPECTROSCOPY: EMISSION LINES FROM THE IONIZED CIRCUMSTELLAR MATERIAL AROUND &lt;10-DAY-OLD TYPE II SUPERNOVAE

    Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material around <10-day-old Type II Supernovae. , keywords =. doi:10.3847/0004-637X/818/1/3 , archivePrefix =. 1512.00846 , primaryClass =

    work page doi:10.3847/0004-637x/818/1/3

  24. [24]

    , keywords =

    SN 2015ba: a Type IIP supernova with a long plateau. , keywords =. doi:10.1093/mnras/sty1634 , archivePrefix =. 1806.05470 , primaryClass =

    work page doi:10.1093/mnras/sty1634

  25. [25]

    , keywords =

    A Wolf-Rayet-like progenitor of SN 2013cu from spectral observations of a stellar wind. , keywords =. doi:10.1038/nature13304 , archivePrefix =. 1406.7640 , primaryClass =

    work page doi:10.1038/nature13304

  26. [26]

    , keywords =

    Explosion of red-supergiant stars: Influence of the atmospheric structure on shock breakout and early-time supernova radiation. , keywords =. doi:10.1051/0004-6361/201730942 , archivePrefix =. 1704.01697 , primaryClass =

    work page doi:10.1051/0004-6361/201730942

  27. [27]

    2012, MNRAS, 423, 600, doi: 10.1111/j.1365-2966.2012.20901.x

    Progenitor mass constraints for core-collapse supernovae from correlations with host galaxy star formation. , keywords =. doi:10.1111/j.1365-2966.2012.21324.x , archivePrefix =. 1205.3802 , primaryClass =

    work page doi:10.1111/j.1365-2966.2012.21324.x 2012

  28. [28]

    , keywords =

    Unifying Type II Supernova Light Curves with Dense Circumstellar Material. , keywords =. doi:10.3847/1538-4357/aa6251 , archivePrefix =. 1610.08054 , primaryClass =

    work page doi:10.3847/1538-4357/aa6251

  29. [29]

    VizieR Online Data Catalog , keywords =

    VizieR Online Data Catalog: Type IIP supernovae from Pan-STARRS1 (Sanders+, 2015). VizieR Online Data Catalog , keywords =

    2015

  30. [30]

    Final Moments. II. Observational Properties and Physical Modeling of Circumstellar-material-interacting Type II Supernovae. , keywords =. doi:10.3847/1538-4357/ad4a2a , archivePrefix =. 2403.02382 , primaryClass =

    work page doi:10.3847/1538-4357/ad4a2a

  31. [31]

    2012, MNRAS, 423, 600, doi: 10.1111/j.1365-2966.2012.20901.x

    An empirical relation between sodium absorption and dust extinction. , keywords =. doi:10.1111/j.1365-2966.2012.21796.x , archivePrefix =. 1206.6107 , primaryClass =

    work page doi:10.1111/j.1365-2966.2012.21796.x 2012

  32. [32]

    Transient Name Server Classification Report , keywords =

    ePESSTO+ Transient Classification Report for 2020-02-02. Transient Name Server Classification Report , keywords =

    2020

  33. [33]

    Transient Name Server Discovery Report , keywords =

    DLT40 Transient Discovery Report for 2020-01-26. Transient Name Server Discovery Report , keywords =

    2020

  34. [34]

    Handbook of Supernovae , year = 2017, editor =

    Shock Breakout Theory. Handbook of Supernovae , year = 2017, editor =. doi:10.1007/978-3-319-21846-5_33 , adsurl =

    work page doi:10.1007/978-3-319-21846-5_33 2017

  35. [35]

    doi:10.5281/zenodo.4312178 , url =

    Griffin Hosseinzadeh and Sebastian Gomez , title =. doi:10.5281/zenodo.4312178 , url =

    work page doi:10.5281/zenodo.4312178

  36. [36]

    , keywords =

    UV/Optical Emission from the Expanding Envelopes of Type II Supernovae. , keywords =

  37. [37]

    , keywords =

    Light curves and H luminosities as indicators of ^ 56 Ni mass in type IIP supernovae. , keywords =. doi:10.1051/0004-6361:20030522 , archivePrefix =. astro-ph/0304144 , primaryClass =

    work page doi:10.1051/0004-6361:20030522

  38. [38]

    , keywords =

    A meta-analysis of core-collapse supernova ^ 56 Ni masses. , keywords =. doi:10.1051/0004-6361/201935027 , archivePrefix =. 1906.00761 , primaryClass =

    work page doi:10.1051/0004-6361/201935027 1906

  39. [39]

    , keywords =

    A two-component model for fitting light curves of core-collapse supernovae. , keywords =. doi:10.1051/0004-6361/201527931 , archivePrefix =. 1602.04001 , primaryClass =

    work page doi:10.1051/0004-6361/201527931

  40. [40]

    , keywords =

    A low-luminosity core-collapse supernova very similar to SN 2005cs. , keywords =. doi:10.1093/mnras/staa1743 , archivePrefix =. 2007.07650 , primaryClass =

    work page doi:10.1093/mnras/staa1743 2007

  41. [41]

    , keywords =

    Non-equilibrium radiative transfer in supernova theory : models of linear type II supernovae. , keywords =

  42. [42]

    , year = 2011, month = feb, volume =

    SYNAPPS: Data-Driven Analysis for Supernova Spectroscopy. , year = 2011, month = feb, volume =. doi:10.1086/658673 , adsurl =

    work page doi:10.1086/658673 2011

  43. [43]

    , keywords =

    Direct Analysis of Spectra of Type Ib Supernovae. , keywords =. doi:10.1086/338127 , archivePrefix =. astro-ph/0106367 , primaryClass =

    work page doi:10.1086/338127

  44. [44]

    , year = 1957, month = oct, volume =

    The Diffusion of L Radiation in Nebulae and Stellar Envelopes. , year = 1957, month = oct, volume =

    1957

  45. [45]

    , keywords =

    SN 2013ej: A Type IIL Supernova with Weak Signs of Interaction. , keywords =. doi:10.1088/0004-637X/806/2/160 , archivePrefix =. 1504.06207 , primaryClass =

    work page doi:10.1088/0004-637x/806/2/160

  46. [46]

    , keywords =

    H _ Spectral Diversity of Type II Supernovae: Correlations with Photometric Properties. , keywords =. doi:10.1088/2041-8205/786/2/L15 , archivePrefix =. 1403.7089 , primaryClass =

    work page doi:10.1088/2041-8205/786/2/l15 2041

  47. [47]

    , keywords =

    Supernova Explosions of Super-asymptotic Giant Branch Stars: Multicolor Light Curves of Electron-capture Supernovae. , keywords =. doi:10.1088/2041-8205/771/1/L12 , archivePrefix =. 1305.6813 , primaryClass =

    work page doi:10.1088/2041-8205/771/1/l12 2041

  48. [48]

    ATLAS: A High-Cadence All-Sky Survey System

    ATLAS: A High-cadence All-sky Survey System. , keywords =. doi:10.1088/1538-3873/aabadf , archivePrefix =. 1802.00879 , primaryClass =

    work page Pith review doi:10.1088/1538-3873/aabadf

  49. [49]

    , keywords =

    SN 2016gsd: an unusually luminous and linear Type II supernova with high velocities. , keywords =. doi:10.1093/mnras/staa365 , archivePrefix =. 1909.13617 , primaryClass =

    work page doi:10.1093/mnras/staa365 1909

  50. [50]

    , keywords =

    Photometric and polarimetric observations of fast declining Type II supernovae 2013hj and 2014G. , keywords =. doi:10.1093/mnras/stv2351 , archivePrefix =. 1510.01927 , primaryClass =

    work page doi:10.1093/mnras/stv2351

  51. [51]

    2012, MNRAS, 420, 1825, doi: 10.1111/j.1365-2966.2011.19805.x

    The Type IIP SN 2007od in UGC 12846: from a bright maximum to dust formation in the nebular phase. , keywords =. doi:10.1111/j.1365-2966.2011.19128.x , archivePrefix =. 1102.5468 , primaryClass =

    work page doi:10.1111/j.1365-2966.2011.19128.x 2011

  52. [52]

    , keywords =

    Diversity of supernovae and impostors shortly after explosion. , keywords =. doi:10.1051/0004-6361/201833779 , archivePrefix =. 1811.06505 , primaryClass =

    work page doi:10.1051/0004-6361/201833779

  53. [53]

    , keywords =

    The Distance to SN 1999em from the Expanding Photosphere Method. , keywords =. doi:10.1086/322450 , archivePrefix =. astro-ph/0105006 , primaryClass =

    work page doi:10.1086/322450

  54. [54]

    , keywords =

    The Distance to SN 1999em in NGC 1637 from the Expanding Photosphere Method. , keywords =. doi:10.1086/324785 , archivePrefix =. astro-ph/0109535 , primaryClass =

    work page doi:10.1086/324785

  55. [55]

    , keywords =

    The Cepheid Distance to NGC 1637: A Direct Test of the Expanding Photosphere Method Distance to SN 1999em. , keywords =. doi:10.1086/376831 , archivePrefix =. astro-ph/0305259 , primaryClass =

    work page doi:10.1086/376831

  56. [56]

    L., & Haiman, Z

    SN 2005cs in M51 - II. Complete evolution in the optical and the near-infrared. , keywords =. doi:10.1111/j.1365-2966.2009.14505.x , archivePrefix =. 0901.2075 , primaryClass =

    work page doi:10.1111/j.1365-2966.2009.14505.x 2009

  57. [57]

    A., Heckman, T

    SN 2005cs in M51 - I. The first month of evolution of a subluminous SN II plateau. , keywords =. doi:10.1111/j.1365-2966.2006.10587.x , archivePrefix =. astro-ph/0605700 , primaryClass =

    work page doi:10.1111/j.1365-2966.2006.10587.x 2006

  58. [58]

    , keywords =

    Type II Plateau supernovae as metallicity probes of the Universe. , keywords =. doi:10.1093/mnras/stu417 , archivePrefix =. 1403.1167 , primaryClass =

    work page doi:10.1093/mnras/stu417

  59. [59]

    Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD

    Measuring Reddening with Sloan Digital Sky Survey Stellar Spectra and Recalibrating SFD. , keywords =. doi:10.1088/0004-637X/737/2/103 , archivePrefix =. 1012.4804 , primaryClass =

    work page Pith review doi:10.1088/0004-637x/737/2/103

  60. [60]

    J., Valenti, S., et al

    The Early Detection and Follow-up of the Highly Obscured Type II Supernova 2016ija/DLT16am. , keywords =. doi:10.3847/1538-4357/aaa014 , archivePrefix =. 1711.03940 , primaryClass =

    work page doi:10.3847/1538-4357/aaa014

  61. [61]

    Type II Supernova Spectral Diversity. I. Observations, Sample Characterization, and Spectral Line Evolution. , keywords =. doi:10.3847/1538-4357/aa8f52 , archivePrefix =. 1709.02487 , primaryClass =

    work page doi:10.3847/1538-4357/aa8f52

  62. [62]

    J., 2009, @doi [ ] 10.1146/annurev-astro-082708-101737 , https://ui.adsabs.harvard.edu/abs/2009ARA&A..47...63S 47, 63

    Progenitors of Core-Collapse Supernovae. , keywords =. doi:10.1146/annurev-astro-082708-101737 , archivePrefix =. 0908.0700 , primaryClass =

    work page doi:10.1146/annurev-astro-082708-101737

  63. [63]

    , keywords =

    Observational Constraints on the Progenitors of Core-Collapse Supernovae: The Case for Missing High-Mass Stars. , keywords =. doi:10.1017/pasa.2015.17 , archivePrefix =. 1504.02635 , primaryClass =

    work page doi:10.1017/pasa.2015.17 2015

  64. [64]

    , keywords =

    The Berkeley sample of Type II supernovae: BVRI light curves and spectroscopy of 55 SNe II. , keywords =. doi:10.1093/mnras/stz2714 , archivePrefix =. 1909.13813 , primaryClass =

    work page doi:10.1093/mnras/stz2714 1909

  65. [65]

    , keywords =

    SN 2009ib: a Type II-P supernova with an unusually long plateau. , keywords =. doi:10.1093/mnras/stv857 , archivePrefix =. 1504.02404 , primaryClass =

    work page doi:10.1093/mnras/stv857

  66. [66]

    , keywords =

    SN 2015an: a normal luminosity type II supernova with low expansion velocity at early phases. , keywords =. doi:10.1093/mnras/stz2703 , archivePrefix =. 1909.10602 , primaryClass =

    work page doi:10.1093/mnras/stz2703 1909

  67. [67]

    ASASSN-16ab: a transitional Type II supernova

    SN 2016B a.k.a. ASASSN-16ab: a transitional Type II supernova. , keywords =. doi:10.1093/mnras/stz949 , archivePrefix =. 1904.01844 , primaryClass =

    work page doi:10.1093/mnras/stz949 1904

  68. [68]

    SN 2018hwm, a faint event with an unusually long plateau

    Low-luminosity Type II supernovae - III. SN 2018hwm, a faint event with an unusually long plateau. , keywords =. doi:10.1093/mnras/staa3730 , archivePrefix =. 2011.11297 , primaryClass =

    work page doi:10.1093/mnras/staa3730 2011

  69. [69]

    SN 2020cxd and SN 2021aai, at the edges of the sub-luminous supernovae class

    Low luminosity Type II supernovae - IV. SN 2020cxd and SN 2021aai, at the edges of the sub-luminous supernovae class. , keywords =. doi:10.1093/mnras/stac1182 , archivePrefix =. 2203.03988 , primaryClass =

    work page doi:10.1093/mnras/stac1182

  70. [70]

    doi:10.5281/zenodo.6519623 , url =

    Griffin Hosseinzadeh and Sebastian Gomez , title =. doi:10.5281/zenodo.6519623 , url =

    work page doi:10.5281/zenodo.6519623

  71. [71]

    , keywords =

    SN 2017gmr: An Energetic Type II-P Supernova with Asymmetries. , keywords =. doi:10.3847/1538-4357/ab43e3 , archivePrefix =. 1907.01013 , primaryClass =

    work page doi:10.3847/1538-4357/ab43e3 1907

  72. [72]

    , keywords =

    SN 2018zd: an unusual stellar explosion as part of the diverse Type II Supernova landscape. , keywords =. doi:10.1093/mnras/staa2273 , archivePrefix =. 2007.14348 , primaryClass =

    work page doi:10.1093/mnras/staa2273 2007

  73. [73]

    , keywords =

    Enormous explosion energy of Type IIP SN 2017gmr with bipolar ^ 56 Ni ejecta. , keywords =. doi:10.1093/mnras/stab1369 , archivePrefix =. 2105.04606 , primaryClass =

    work page doi:10.1093/mnras/stab1369

  74. [74]

    , keywords =

    Environments of interacting transients: impostors and Type IIn supernovae. , keywords =. doi:10.1093/mnras/stu684 , archivePrefix =. 1404.2282 , primaryClass =

    work page doi:10.1093/mnras/stu684

  75. [75]

    A., Gal-Yam, A., et al

    Confined dense circumstellar material surrounding a regular type II supernova. Nature Physics , keywords =. doi:10.1038/nphys4025 , archivePrefix =. 1701.02596 , primaryClass =

    work page doi:10.1038/nphys4025

  76. [76]

    , keywords =

    SN 2015bf: A fast declining type II supernova with flash-ionized signatures. , keywords =. doi:10.1093/mnras/stab1550 , adsurl =

    work page doi:10.1093/mnras/stab1550

  77. [77]

    Nature Astronomy , keywords =

    The electron-capture origin of supernova 2018zd. Nature Astronomy , keywords =. doi:10.1038/s41550-021-01384-2 , archivePrefix =. 2011.02176 , primaryClass =

    work page doi:10.1038/s41550-021-01384-2 2011

  78. [78]

    7737, Observatory Operations: Strategies, Processes, and Systems III, ed

    PySALT: the SALT science pipeline. Observatory Operations: Strategies, Processes, and Systems III , year = 2010, editor =. doi:10.1117/12.857000 , adsurl =

    work page doi:10.1117/12.857000 2010

  79. [79]

    Astronomical Data Analysis Software and Systems XXVII , year = 2019, editor =

    DRAGONS - Data Reduction for Astronomy from Gemini Observatory North and South. Astronomical Data Analysis Software and Systems XXVII , year = 2019, editor =

    2019

  80. [80]

    J., Valenti, S., Fraser, M., et al

    PESSTO: survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects. , keywords =. doi:10.1051/0004-6361/201425237 , archivePrefix =. 1411.0299 , primaryClass =

    work page doi:10.1051/0004-6361/201425237

Showing first 80 references.