2004/06/01 by Nathan Smith · 3 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.07943.x
published as Mon.Not.Roy.Astron.Soc. 351 (2004) L15 · 4 pages, published in MNRAS
openalex publication_date 2004/06/01 · arxiv created 2004/06/23 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
High-resolution spectra of molecular hydrogen in the Homunculus nebula allow for the first direct measurement of the systemic velocity of η Carinae. Near-infrared long-slit data for H2 1–0 S(1) λ21218 obtained with the Phoenix spectrometer on the Gemini South telescope give Vsys=−8.1 ± 1 km s−1 (heliocentric), or VLSR=−19.7 ± 1 km s−1, from the average of the near and far sides of the Homunculus. This measurement considerably improves the precision for the value of −7 ± 10 km s−1 inferred from neighbouring O-type stars in the Carina nebula. New near-infrared spectra also provide a high-resolution line profile of [Fe ii]λ16435 emission from gas condensations known as the Weigelt objects without contamination from the central star, revealing a line shape with complex kinematic structure. Previously, uncertainty in the kinematics of the Weigelt knots was dominated by the adopted systemic velocity of η Car.