# The interacting binary V 393 Scorpii: another clue for Double Periodic Variables

## TL;DR

This paper investigates the spectroscopic properties of V 393 Scorpii, revealing how its long cycle is driven by a relaxation cycle in the circumprimary disc related to mass transfer and instability.

## Contribution

It provides new spectroscopic insights into the long cycle behavior of V 393 Scorpii, supporting the relaxation cycle model for Double Periodic Variables.

## Key findings

- H alfa emission varies with the long cycle
- Radial velocity of He I 5875 modulates with the long cycle
- Long cycle explained as a relaxation cycle in the circumprimary disc

## Abstract

We give a brief report on spectroscopic properties of V 393 Scorpii. H alfa emission and shape and radial velocity of He I 5875 are modulated with the long cycle. The long cycle is explained as a relaxation cycle in the circumprimary disc, that cumulates the mass transferred from the donor until certain instability produces disc depletion.