Italialainen professori kaipaa apua 20.3. pimennyksen tarkkailussa

[Anne Liljeström]

Ursaan tuli yhteydenotto Rooman Sapienza-yliopiston professori Costantino Sigismondilta, joka haluaisi havaintoja pimennyksen kulusta Suomessa (ymmärtääkseni muutkin paikkakunnat kuin Helsinki käyvät, vaikka hän puhuukin alla Helsingistä). Lupasin levittää sanaa havaitsijoille, jos joku haluaisi ottaa osaa Sigismondin tutkimukseen. Tietoja alla kerättynä kahdesta sähköpostista (efemeridejä ei ollut liitteenä, mutta ne voi tarvittaessa varmasti pyytää Sigismondilta). Jos yhteistyö kiinnostaa, häneen kannattaa olla suoraan yhteydessä.

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Since I am gathering good quality images or better videos of the first and last contact
to obtain the measurement of the solar diameter and I want to check how precise is to use partial eclipse data

I ask you if you can gather me in this project; in attachment you find the ephemerides of the eclipse for your location

videos with UTC from 1 minute before to 2 minutes after the beginning at 11:00 AM and
2 minute before and 1 after the end at 13:15 PM would be perfect.

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I am asking you two 2 minutes video of the beginning and of the end of the eclipse of march 20th.

the videos should be referenced with a radiocontrolled watch (filmed in the same video at the beginning or at the end)
if this is difficult, the video should have the time of the camcorder (that has not to be adjusted during the eclipse, because
the time flows generally without dramatic drifts in 2 hours).

the scope is to measure the solar diameter by timing the first and the last contact (in the file attached the predicted instants for helsinki)
if the timing is 1/30 s accurate, along 2 hours the relative resolution can be    1/(7200*30)  so very interesting!

in practice 1/10 s is thinkable, but we will see.

So the procedure to get that in case of internal clock present in the videocamera can be
1) a video of calibration of the screen of a radiocontrolled watch 1 hour before the eclipse
2) the video of the first contact from -30s to + 2 minutes
3) the video of the last contact from -2  minutes to + 30 s
4)a second video of calibration looking at the screen of a radiocontrolled watch 1 hour after the eclipse

in my experience in 2 hours every quartz watch is stable within 0.2 s. But we can control it with these videos of calibration.

At disposition for more clarifications.

Greetings from Rome

Costantino Sigismondi
www.icra.it/solar

sigismondi.costantino @ gmail.com