Stability of the interstellar hydrogen inflow longitude from 20 years of SOHO/SWAN observations
Résumé
A recent debate on the decade-long stability of the interstellar He flow vector, and in particular the flow longitude, has prompted us to check for any variability in the interstellar H flow vector as observed by the SWAN instrument on board SOHO.
We used a simple model-independent method to determine the interstellar H flow longitude, based on the parallax effects induced on the Lyman-α intensity measured by SWAN following the satellite motion around the Sun.
Our results show that the interstellar H flow vector longitude does not vary significantly from an average value of 252.9◦ ± 1.4◦ throughout the 20-year span of the SWAN dataset, further strengthening the arguments for the stability of the interstellar gas flow.
Origine | Fichiers éditeurs autorisés sur une archive ouverte |
---|
Loading...