Main Objective: Mercury will transit the Sun on 2016 May 9. We would like to use Hinode to observe the event with SOT, XRT, and EIS. The next opportunity will not be until the transit of November 2019. This HOP defines the overall plan for Hinode observations of this Transit of Mercury (ToM).
Details of the observation schedule will have to be put together by the planning team after the Hinode observation and orbit timings are better defined (e.g., twilight and/or night timings).
Scientific Justification: Our observational objectives are multi-fold: (a) We will study the black drop effect in white-light with SOT during contacts I and IV. A convincing explanation for this long-observed effect has been presented only recently (e.g., Schneider et al. 2004, Pasachoff et al. 2011). We will seek to gain further insight into the phenomenon with SOT images. (b) Image in Ca II as Mercury crosses spicules (or a prominence) at the limb; this could be useful, e.g., characterizing spicule widths. (c) Use SOT/NFI observations in the Na D1 line, to attempt to image exospheric absorption. (d) Polarization measurements with SOT/SP to characterize the polarization state of the instrumental scattered light. (e) Observations from XRT to observe Mercury silhouetted against the coronal background before, during, and after the transit. (f) The above SOT and XRT images, and also EIS slot images can be taken for public outreach and media releases. The public component should complement nicely the exceptional public images from the 2012 transit of Venus. (g) Complementary images should be obtained with IRIS slit jaw images for public outreach.
References: Pasachoff, J. M., Schneider, G. & Widemann, T. 2011, Astron. J 2011, 141, 112 Schneider, G., Pasachoff, J. M., & Golub, L. 2004, Icarus, 168, 249 |
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