Paranal sunset seen from Armazones


© Stéphane Guisard "Los Cielos de Chile"

Twice per year, the sunset passes exactly behind Paranal (1) mountain for somebody located on the summit of Armazones (2) mountain, 20km away (~12.5 miles). The dates and time (3)  when this happens were calculated using coordinates of both sites found on googleearth and taking into account atmospheric effects. This picture(4) was taken in these conditions. It clearly shows 3 of the 4 big 8m unit telescope (UT) domes (4th one is behind the others), the VST enclosure on their right and the high meteorological post with the DIMM tower on the extreme right. On the left of the picture, the partially opened dome of the smaller 1.8m Auxiliary Telescope(AT) are also visible.
The image was taken with a Takahashi FS128 refractor telescope, a Canon20Da camera and special Solar filters. Please remember that looking at the Sun through an optical device (Camera, Telescope, Binoculars etc…) is VERY dangerous, and could cause immediate blindness.

The following animated gif image was  created from the lower left crops of the several images taken that day. It shows, between the AT and UT1, the movement of Paranal  Staff and astronomers gathering daily on the telescope platform to observe the sunset and its  possible “green flash”…The conclusion is that you can definitively not prevent people from passing in front of your camera when taking a picture !


(1) “Cerro Paranal”  is located in Northern Chile and hosts the ESO Very Large Telescope.
(2)“Cerro Armazones  hosts Universidad Catolica del Norte  observatory .
(3) If you want to do the calculation yourself, write me, I will be happy to read about your “prognostic”, sorry…nothing to win….
(4) The idea of this picture actually came to me many years ago, during the first light of the VLT, while working the night and running up the mountain during the day with my colleague Lothar. It is however only recently that I took the time to calculate the dates for the event and take the picture.