# C_PHASE_INDEX.txt
# STELLAR_BOUNDARY_DYNAMICS_I
# Phase C — Spectral Time Series

PHASE:
C_spectral_time_series

PARENT DATASET:
stellar_boundary_dynamics

PURPOSE:
Build a spectral time-series layer that tests whether element-line evolution
supports, modifies, or contradicts the separation/contact pattern found in the
A–B bridge.

A–B BRIDGE CONTEXT:
Phase A:
real pre-supernova radial support/composition profiles

Phase B:
observed post-collapse light-curve response trajectories

Phase C:
observed post-collapse spectral element-line evolution

The A–B bridge found weak separation between A and B reviewed v2 vector domains.
The closest A–B pair was A2_20M ↔ B_SN1993J.
The strongest outlier remained B_SN2012aw.

PHASE C QUESTION:
Does spectral element-line evolution preserve the same pattern?

Specifically:
1. Does SN1993J remain structurally close/contact-like when spectral evolution is
   used instead of brightness-response ladders?

2. Does SN2012aw remain structurally special/outlying when spectral evolution is
   used instead of brightness-response ladders?

3. Do element-line ladders form connected STRUC-PERC-I structures?

4. Do spectral-line α-vectors bridge B light-curve behavior to A pre-supernova
   composition/support structure?

PRIMARY SOURCE:
WISeREP — Weizmann Interactive Supernova Data Repository

SOURCE URL:
https://www.wiserep.org/

SOURCE ROLE:
Primary source for public supernova spectra.

SECONDARY SOURCE:
Open Supernova Catalog / AstroCats

SOURCE URL:
https://github.com/astrocatalogs/supernovae

SOURCE ROLE:
Secondary source for spectra metadata and object-level catalog cross-checks.

TARGET PILOT OBJECTS:
SN1993J
SN2012aw

WHY THESE TWO FIRST:
SN1993J:
Closest Phase B object to A2_20M in the A–B bridge.
This is the contact-case spectral test.

SN2012aw:
Strongest high-tail/high-kappa outlier in Phase B and most separated object
in the A–B bridge context.
This is the outlier-case spectral test.

FULL TARGET OBJECT SET:
SN1987A
SN1993J
SN1999em
SN2011dh
SN2012aw
SN2013ej

PILOT ORDER:
C1_SN1993J
C2_SN2012aw
C3_SN1987A
C4_SN1999em
C5_SN2011dh
C6_SN2013ej

DIRECTORY STRUCTURE:
C_spectral_time_series/
  C_PHASE_INDEX.txt

  sources/
    C_SOURCE_INDEX.txt
    WISeREP/
    AstroCats/

  raw/
    C1_SN1993J/
    C2_SN2012aw/

  selected_objects/
    C_PILOT_OBJECTS.txt

  ladders/
    C1_SN1993J_spectral_line_ladder.csv
    C2_SN2012aw_spectral_line_ladder.csv

  struc_perc_i/
    canonical_inputs/
    numeric_ladders/
    summaries/

  alpha_application/
    grids/
    vectors/
    summaries/
    normalization_review/

  tools/
    c_spectra_to_line_ladder.py
    c_line_ladder_to_struc_perc_i.py
    c_alpha_apply.py
    c_alpha_normalization_review.py

TARGET SPECTRAL FEATURES:
H_alpha
H_beta
He_I
O_I
Ca_II
Si_II
Fe_II
Ni_Co_decay_proxy

LINE / FEATURE WINDOWS:
H_alpha:
rest wavelength ≈ 6563 Å

H_beta:
rest wavelength ≈ 4861 Å

He_I:
rest wavelength ≈ 5876 Å

O_I:
rest wavelength ≈ 7774 Å

Ca_II:
near-infrared triplet ≈ 8498, 8542, 8662 Å

Si_II:
rest wavelength ≈ 6355 Å

Fe_II:
representative optical blends around ≈ 4924, 5018, 5169 Å

Ni_Co_decay_proxy:
late-time spectral/nebular features where available; exact feature handling
depends on available spectra and metadata.

RAW SPECTRA REQUIREMENTS:
For each object, collect multiple spectra across time.

Minimum useful pilot:
at least 3 spectra per object

Preferred:
5–10 spectra per object spanning:
early phase
near peak
early decline
late/nebular if available

RAW FILE TYPES EXPECTED:
txt
dat
ascii
csv
fits

DO NOT ASSUME FORMAT YET:
The converter c_spectra_to_line_ladder.py should be created only after raw
spectra are downloaded and the actual file format is inspected.

METADATA TO PRESERVE:
object_name
spectrum_date
phase_days if available
redshift if available
instrument if available
source/archive
reference
wavelength unit
flux unit
filename

SPECTRAL LADDER TARGET:
Each spectrum becomes one or more line-feature rows.

Expected ladder row:
object_id
object_name
spectrum_id
spectrum_date
phase_days
line_id
line_name
rest_wavelength
observed_wavelength_window
continuum_level
line_flux_proxy
line_depth_proxy
equivalent_width_proxy
velocity_proxy
width_proxy
signal_quality_proxy
element_group
spectral_phase_role
raw_reference

STRUC-PERC-I CANONICAL TARGET:
Compress spectral line ladders into object × line × phase structural rows.

Potential canonical fields:
object_id
object_name
line_name
element_group
phase_bin
phase_mid
line_strength
line_strength_change
velocity_proxy
width_proxy
equivalent_width_proxy
gap
support_regime_proxy
boundary_role
alpha_ready

NUMERIC LADDER TARGET:
Construct monotone cumulative spectral gaps from:
line-strength change
velocity change
width change
equivalent-width change
line emergence/disappearance
element-group transitions

PHASE C STRUC-PERC-I QUESTION:
Do spectral element-line ladders percolate as connected observable
post-boundary structures?

PHASE C ALPHA QUESTION:
Do spectral line-feature ladders remain stable under α-deformation?

PHASE C BRIDGE QUESTIONS:
B–C:
Do light-curve response vectors and spectral-line evolution vectors align for
the same objects?

A–C:
Do pre-supernova composition/support vectors align more closely with spectral
element-line evolution than with brightness-response curves?

A–B–C:
Can the three-layer chain be represented as:

pre-supernova radial composition/support structure
→ post-collapse brightness-response trajectory
→ post-collapse element-line redistribution trajectory

VALID CLAIM TARGET:
Phase C can support a structural comparison of element-line evolution against
the already processed A and B domains.

INVALID CLAIMS:
Do not claim nucleosynthesis yield prediction from spectral ladders alone.
Do not claim detailed radiative-transfer modeling.
Do not claim direct core-composition measurement from optical spectra.
Do not claim that spectral features are complete abundance maps.

NEXT IMMEDIATE ACTION:
Create source notes for WISeREP and AstroCats.

Then collect pilot spectra for:
C1_SN1993J
C2_SN2012aw

Do not write c_spectra_to_line_ladder.py until at least one raw spectrum file
has been downloaded and its format inspected.

STATUS:
Phase C folders initialized.
Phase C index created.
Ready for source notes and pilot spectra acquisition.
