As viewed from Jupiter, Venus will transit the Sun on 2012 September 20. This will result in a decrease in the reflected solar irradiance off of Jupiter. A separate proposal has been accepted by the Hubble Space Telescope (HST) team to observe Jupiter at multiple wavelengths with HST around and during the transit time in an attempt to detect the reflected-intensity drop. During the transit time, it is possible that there will be subtle variations in that Jovian reflected intensity level resulting from Venus crossing specific solar features (e.g., sunspots). This proposal is for Hinode SOT observations to support the HST study by observing with high resolution the regions of the Sun that reside along the path that will be covered by Venus as seen from Jupiter; that is, Hinode will observe the ``footprint'' on the Sun of the Venus-as-seen-from-Jupiter track.
The potential Hinode observations will be restricted to times if and when this footprint crosses the expected location of active regions. Major Flare Watch observations, or other major Hinode observations, have a higher priority than these JToV observations.
The footprint of the JToV path of Venus across the Sun as seen from Hinode has been provided by a HOP team member (G. Schneider). The JToV footprint will be visible from Hinode on 20 September 2012, 4:23 - 11:26 UT. On that day, Venus as seen from Earth will be ~17'' in diameter, and hence this is the angular size of the deprojected JToV footprint of Venus. Using this information, and assuming an SOT FOV of about 200'' X 100'', we have determined the needed pointings for the period of time. That information is given in the Remarks section below.
The procedure will be for the CP and COs to consider whether and when the specified pointings will possibly contain an AR in the SOT FOV. If possible, they will include pointings to the JToV target when the AR is predicted to be in that FOV. HOP member A. Sterling is to be Hinode Chief Planner (CP) on the upload days of Tuesday 18 Sep and Thursday 20 Sep. Sterling has talked with T. Yasuda, who will be CP for the preliminary planning on Monday 17 Sep. |
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