Evaporated atmosphere in the interplanetary medium of early-type stars

Evaporated atmosphere in the interplanetary medium of early-type stars Alexandra Lehtmets Young Research Fellow In collaboration with M. Kama, L. Fossati and A. Aret 10.09.2024 MAIN GOAL To find the potential chemical species from evaporated atmospheres that can contaminate the photospheres of early-type stars! IDEAJermyn and Kama 2018 Understanding star-planet interactions Shedding light on atmospheric evolution Implications for exoplanet composition STAR PARAMETERS 𝑇𝑒𝑓𝑓 ≈ 4200 – 19,100 K Age = 20 Myr Log g = 4.5 SCHEMATIC OF THE MODEL NIST atomic database (H to Ni) ATLAS9 fluxes 𝛽 = 𝐹𝑟𝑎𝑑 𝐹 𝑔𝑟𝑎𝑣 𝑣𝑖𝑜𝑛 = 𝛽 𝐺𝑀 𝑟2 1 Γ I I, II, III MODEL INPUT TABELS FOR βAND 𝑣𝑖𝑜𝑛 SOLUTIONS OUTPUT Fernandez et al. 2005 XCOM (H to Ni) CMD ver. 3.7 evolutionary tracks Stellar masses βRESULTS Lehtmets et al., in prep. NEUTRAL Noble gases (He, Ne, … ) – slightly affects Non-metals (N, F, …) – moderately affects Metals (Li, Na, …) -highly affects βRESULTS Lehtmets et al., in prep. SINGLY IONISED Noble gases (He, Ne, … ) – slightly affects Non-metals (N, F, …) – moderately affects Metals (Li, Na, …) -highly affects βRESULTS Lehtmets et al., in prep. DOUBLY IONISED Noble gases (He, Ne, … ) – slightly affects Non-metals (N, F, …) – moderately affects Metals (Li, Na, …) -highly affects βRESULTS Comparison between neutral and ionised species. β goes down with increasing ionisation, so ionised chemical species are less affected by the radiation pressure. Lehtmets et al., in prep. 𝑣𝑖𝑜𝑛 RESULTS Most of the neutral atoms are quickly leaving the system before being ionised and dragged back towards the star. 𝑣𝑖𝑜𝑛 = 𝛽 𝐺𝑀 𝑟2 1 Γ Lehtmets et al., in prep.