Астронет: Астрономическая картинка дня Солярографические аналеммы http://variable-stars.ru/db/msg/1839872/eng |
Credit & Copyright: Dawid Rycabel
(Pinholove)
Explanation:
For the northern hemisphere June 21 was the summer solstice,
the
Sun reaching
its northernmost declination for the year.
That would put it at the top of each of these three
figure-8 curves, or analemmas,
as it passed through the daytime sky over the village of Proboszczow, Poland.
No sequence of digital exposures was used to construct the
remarkable image though.
Using a pinhole camera fixed
to face south
during the period June 26, 2021 to June 26, 2022,
the image was formed directly on a single sheet of photographic paper, a
technique
known as solargraphy.
The three analemmas are the result of briefly exposing the photo
paper through the pinhole each day at 11:00, 12:00, and 13:00 CET.
Groups of dashed lines on the sides show partial tracks of the Sun
from daily exposures made every 15 minutes.
Over the year-long
solargraphic photo opportunity
clouds blocking the Sun during the pinhole exposures created
the dark gaps.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.