2003/09/25 by Hiroshi Imai, Imai, Hiroshi, P. J. Diamond +2
Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0309682
5 pages, 2 figures, presented at the conference "Future Directions in High Resolution Astronomy: A Celebration of the 10th Anniversary of the VLBA", held in June 8-12, 2003, in Socorro, New Mexico, USA; to be published in the ASP Conference Series
arxiv created 2003/09/25 · openalex publication_date 2003/09/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
With the VLBA, we have observed water masers associated with the OH/IR star, W43A, which trace a birth and growth of a molecular jet. The water masers exhibit the collimated distribution (1700 AU: 20 AU) and fast motions (+/-150 km/s). The maser distribution was well fit by a precessing jet model. The jet length has extended by 800 AU within 8 years, indicating that the extension rate is roughly equivalent to the jet speed (150 km/s). Very likely the jet was born around the year 1960. An elongated planetary nebula will be formed by such a jet during an extremely short period (<<1000 yrs) of the transition to form a ptoto-planetary nebula. Then fading of the water maser jet will be observed during our human life.