Schedule

Unfortunately, since months no sunspots offer possibilities of position measurements. Nevertheless, we hope that the participants have used the time for exercises in focussing, suitable exposuring and multiple exposuring as described in our page Exercises. Until about one week before the transit typical results of those exercises may be published via the page Data exchange. Some days before the transit the databases will be cleared.

Shortly before the transit, the own clock and the clock of the camera must be adjusted to the split second - preferably to universal time UT!

In order to magnify the probability of finding simultaneously taken images from distant places we propose to photograph Sun and Mercury during the transit all halfs of an hour, i.e. exactly at 13:00, 13:30, ..., 18:00 UT. (If you are not certain about the difference between your local time and Universal time look at heavens above.) Special attention should be focussed onto the times 13:00, 15:00 and 17:00 UT.
The different importance of the appointed times may be visualized in the following manner:

Schedule for Photographing
12:45	13:00	13:15	13:30	13:45	14:00	14:15	14:30
14:45	15:00	15:15	15:30	15:45	16:00	16:15	16:30
16:45	17:00	17:15	17:30	17:45	18:00

In case of double exposuring the first image at a time should always be taken at the proposed times.

If it is for any reason not possible to photograph at these times Mercury should be photographed at arbitrary times as often as possible. Those images will allow to interpolate after the transit (see below).
In order to be able to measure Mercury's position on the solar disc the exact orientation of the pictures must be known. Non professional observers can solve this problem by exposuring their pictures twice. Tips for that procedure are given on this project's page Exercises and on the page photographing of the Venus 2012 project.

For the additional determination of the Sun's angular radius see the project Measuring the angular radius of the Sun of the Venus 2012 project.

Sample pictures may be uploaded via our page Data exchange.

The position of Mercury on these pictures may be measured with the help of the little (Windows-) program evaltransitpicts.
In the case that clouds have made photographing impossible at the fixed moments, the positions may later be determined by interpolation between the positions on pictures taken at earlier and later moments (see below).

The measured positions of Mercury at the above proposed points of time may also be uploaded via our page Data exchange.

The complete position data made by a single participant can be filled into the worksheet tableofMercury2019positions.xls which calculates and displays the parameters of the best linear fit to these positions. The line fit will allow to interpolate to the above mentioned points of time. Additionally, the line fit will allow to derive the contact times by extrapolating the observational data. This is, for instance, be done by the (Windows-) program evaltransitpicts.

The filled worksheet may be uploaded and shown to the other participants via our page Data exchange, too.

For the graphical visualisation of the own measurements we offer the above mentioned (Windows-) program comptransitofmercury2019pos which additionally computes theoretical contact times by extrapolating of the line fit.

Example visualisation of theoretical 2016 results

For the evaluation by combinating the results of two distant sites, we offer to possibilities:
1. the comparison of two simultaneous position measurements with a the little worksheet comp2Mercury2019positions.xls executing the procedure described in our example (the little (Windows-) program calcparallax2019 does the same) and
2. the combination of the line fits of two distant sites, again with the program comptransitofmercury2019pos.
  
  Example comparison of theoretical 2012 results
If you don't find any data from distant sites suitable for being combinated with your own measurements it will temporarily be possible to compare them with calculated geocentric positions. (The calculation of geocentric data is possible without knowing the absolute size of the solar system!)

Example comparison between topocentric and geocentric results
We hope that NASA will publish SDO images of the transit seperated by only one minute (or few minutes) and that we will get the exact positions of that satellite. If so, we will be able to combine project photos with simultaneous SDO images. For these combinations the position angle of the solar north pole must be known. It can be found on JPL's HORIZON's Web-Interface or it can be calculated with the little (Windows-) program solarPosAngle. During the transit the position angle will decrease from 22.3878° to 22.3314°.

The results will be published on the result page of this project.
(The result page of our Transit of Mercury 2016 Project may give an impression of the intended layout.)

Editor:

Udo Backhaus

last update: last update: 2020-02-11

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Transit of Mercury, November 11th, 2019

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