Presence of [Ne V] 3426 Å on day 147.66

Determine whether the [Ne V] 3426 Å emission line is present in the day 147.66 optical spectrum of V1674 Herculis, given its weakness and limited instrumental sensitivity at short wavelengths.

Background

[Ne V] 3426 Å is clearly detected at earlier epochs (day 19.87 to day 65.86), indicating high ionisation consistent with an ONe white dwarf.

At day 147.66, nebular lines persist but high-ionisation iron lines fade; the [Ne V] 3426 Å detection is uncertain because of low sensitivity and weak signal even after spectrum smoothing.