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Vector-apodizing phase plate coronagraph: design, current performance, and future development [Invited].

Applied Optics Optica Publishing Group 60:19 (2021) d52-d72

Authors:

DS Doelman, F Snik, EH Por, SP Bos, GPPL Otten, M Kenworthy, SY Haffert, M Wilby, AJ Bohn, BJ Sutlieff, K Miller, M Ouellet, J de Boer, CU Keller, MJ Escuti, S Shi, NZ Warriner, K Hornburg, JL Birkby, J Males, KM Morzinski, LM Close, J Codona, J Long, L Schatz, J Lumbres, A Rodack, K Van Gorkom, A Hedglen, O Guyon, J Lozi, T Groff, J Chilcote, N Jovanovic, S Thibault, C de Jonge, G Allain, C Vall茅e, D Patel, O C么t茅, C Marois, P Hinz, J Stone, A Skemer, Z Briesemeister, A Boehle, AM Glauser, W Taylor, P Baudoz, E Huby, O Absil, B Carlomagno, C Delacroix

A Spectral Investigation of Aqueously and Thermally Altered CM, CM鈥怉n, and CY Chondrites Under Simulated Asteroid Conditions for Comparison With OSIRIS鈥怰Ex and Hayabusa2 Observations

Journal of Geophysical Research Planets American Geophysical Union (AGU) 126:7 (2021)

Authors:

HC Bates, KL Donaldson Hanna, AJ King, NE Bowles, SS Russell

High-contrast observations of brown dwarf companion HR 2562 B with the vector Apodizing Phase Plate coronagraph

(2021)

Authors:

Ben J Sutlieff, Alexander J Bohn, Jayne L Birkby, Matthew A Kenworthy, Katie M Morzinski, David S Doelman, Jared R Males, Frans Snik, Laird M Close, Philip M Hinz, David Charbonneau

Isotopic fractionation of water and its photolytic products in the atmosphere of Mars

Nature Astronomy Springer Nature 5:9 (2021) 943-950

Authors:

Juan Alday Parejo, Alexander Trokhimovskiy, Patrick GJ Irwin, Colin Wilson, Franck Montmessin, Franck Lef茅vre, Anna A Fedorova, Denis A Belyaev, Kevin S Olsen, Oleg Korablev, Margaux Vals, Lo茂c Rossi, Lucio Baggio, Jean-Loup Bertaux, Andrey Patrakeev, Alexey Shakun

Abstract:

The current Martian atmosphere is about five times more enriched in deuterium than Earth鈥檚, providing direct testimony that Mars hosted vastly more water in its early youth than nowadays. Estimates of the total amount of water lost to space from the current mean D/H value depend on a rigorous appraisal of the relative escape between deuterated and non-deuterated water. Isotopic fractionation of D/H between the lower and the upper atmospheres of Mars has been assumed to be controlled by water condensation and photolysis, although their respective roles in influencing the proportions of atomic D and H populations have remained speculative. Here we report HDO and H2O profiles observed by the Atmospheric Chemistry Suite (ExoMars Trace Gas Orbiter) in orbit around Mars that, once combined with expected photolysis rates, reveal the prevalence of the perihelion season for the formation of atomic H and D at altitudes relevant for escape. In addition, while condensation-induced fractionation is the main driver of variations of D/H in water vapour, the differential photolysis of HDO and H2O is a more important factor in determining the isotopic composition of the dissociation products.

Photolysis controls the isotopic composition of water products escaping Mars鈥 atmosphere

Nature Astronomy Springer Nature 5 (2021) 943-950

Authors:

Juan Alday, Alexander Trokhimovskiy, Patrick Irwin, Colin Wilson, Franck Montmessin, Franck Lef猫vre, Anna Fedorova, Denys Belyaev, Kevin Olsen, Oleg Korablev, Margaux Vals, Lo茂c Rossi, Lucio Baggio, Jean-Loup Bertaux, Andrey Patrakeev, Alexey Shakun

Abstract:

The current Martian atmosphere is about five times more enriched in deuterium than Earth鈥檚, providing direct testimony that Mars hosted vastly more water in its early youth than nowadays. Estimates of the total amount of water lost to space from the current mean D/H value depend on a rigorous appraisal of the relative escape between deuterated and non-deuterated water. Isotopic fractionation of D/H between the lower and the upper atmospheres of Mars has been assumed to be controlled by water condensation and photolysis, although their respective roles in influencing the proportions of atomic D and H populations have remained speculative. Here we report HDO and H2O profiles observed by the Atmospheric Chemistry Suite (ExoMars Trace Gas Orbiter) in orbit around Mars that, once combined with expected photolysis rates, reveal the prevalence of the perihelion season for the formation of atomic H and D at altitudes relevant for escape. In addition, while condensation-induced fractionation is the main driver of variations of D/H in water vapour, the differential photolysis of HDO and H2O is a more important factor in determining the isotopic composition of the dissociation products.