# A retained red alternative is not the supported-visit counterpart

12 October 2026. This additive note displays an already-computed secondary
record in the registered all-alternative colour table. It changes no source
selection, cut, primary count or model and is not another research experiment.
The independent raw-response verifier already checked this record and its colours.

Within the HIGALBM353.4272-0.3734 field, the known Catalog source
**SSTGLMC G353.4284-00.3731** has central [3.6]-[4.5] = **1.000 mag** and
[4.5]-[5.8] = **0.790 mag**, both above the named >0.7 necessary cuts. It has
four valid bands with quoted magnitude errors <0.2 and a zero **4.5-micron**
quality flag. Other-band native quality flags were not retained by the excerpt;
zero in one band does not establish all-band reliability or physical class.

The first colour's 3x quoted-error envelope is [0.772, 1.228], but the second's
is [0.529, 1.051]. Therefore it does **not** meet the registered robust
necessary-colour criterion. These are sensitivity envelopes, not confidence
bounds. The full standard Class-I/II classifier was not implemented or applied.
Extinction, contaminants, blending, physical stage and clump membership remain
unestablished. Central red colour is a reason to inspect, not a confirmed YSO.

The source lies **4.490 arcsec** from the clump centre and matches **0 of 6**
supported query-visit medians inside the frozen 2-arcsecond rule. It is different
from the best positional record, SSTGLMC G353.4273-00.3723, which matches 4/6.
Do not attribute the visit photometry/variability to this red alternative or
replace the registered best source after readout. A clump can have multiple
projected sources; a red neighbour and a changing emitter are different claims.

All source IDs and alternatives remain retained. Its existing GLIMPSE entry is
not a discovery, birth or fresh physical validation. The three fixed best records
still have zero four-band availability and zero robust red-colour support; the
full 19,328-ID denominator and old scores/gates remain unchanged. This note adds
no model fit, observation acquisition, full classification or successor test.

`artifacts/irac_colour_secondary_alternative_20261012.json` binds the exact
native counter, both colour envelopes and prior visit geometry to committed
source revision `106e2f842a903469f7529c54272cbf033509ba43`.
`research/summarize_irac_colour_alternative.py` reproduces this display from those
committed blobs while preserving the original primary and all historical results.