Main Objective: Observe Mercury as it transits the Sun on 2019 November 11
Scientific Justification: Mercury will transit the Sun on 2019 November 11, for the last time until 2032. We (JMP) will observe contacts 3 and 4 from the ground at Big Bear Solar Observatory. We request complementary observations from Hinode. Our ground-based observations are focused on studying the black drop effect. A convincing explanation for this long-observed effect has been presented only within the past couple of decades based on satellite images of the 1999 transit of Mercury (e.g., Schneider et al. 2004, Pasachoff et al. 2011). We will seek to gain further insight into the phenomenon with ground-based observations during contacts 3 and 4. The XRT images will complement the ground observations. We request high-cadence XRT observations at least over the period of contacts 3 and 4 to support these scientific studies.
We also request observations tracking Mercuryfs silhouette across the X-ray disk (at lower cadence than the limb-crossing times would be acceptable). These results will be of importance for public outreach.
Pasachoff, J. M., Schneider, G. & Widemann, T. 2011, Astron. J 2011, 141, 112
Schneider, G., Pasachoff, J. M., & Golub, L. 2004, Icarus, 168, 249