Астронет: Астрономическая картинка дня Австрийская аналемма http://variable-stars.ru/db/msg/1270276/eng |
Credit & Copyright: Robert Pölzl
Explanation:
Today, the
Sun crosses
the celestial equator heading south at 14:49 Universal Time.
An equinox (equal night), this astronomical event marks the
first day of autumn in the northern hemisphere and spring in the south.
With the Sun on the celestial equator, Earth
dwellers will experience
nearly
12 hours of daylight and 12 hours of darkness.
To celebrate, consider
this
careful record of the Sun's yearly journey
through southern Austrian skies.
The
scene is composed of images made at the same time each day,
capturing the Sun's position on dates from
September
29, 2011 through September 9, 2012,.
The multiple suns trace an intersecting curve
known as
an anelemma.
In fact, the past year's two equinox dates correspond to the middle
(not the intersection point)
of
the curve.
The summer and winter solstices are at the top and bottom.
Of course, many would also consider it a good idea
to travel along the mountain road toward the left,
passing the vineyards along the way to reach the nearby town of
Kitzeck
and toast the equinox with a glass of wine.
Near the roadside bench is a
windmill-like klapotetz,
traditionally used in this wine-growing region to keep the birds away.
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.