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Астронет: Астрономическая картинка дня Острова в фотосфере http://variable-stars.ru/db/msg/1194356/eng |
Credit & Copyright: Gunther
Groenez
Explanation:
Awash in a sea of
plasma
and anchored in
magnetic
fields, sunspots are planet-sized, dark islands in
the
solar photosphere, the bright surface of the Sun.
Before the enlightened(!) age of cameras,
solar observers
created detailed
drawings
of sunspots as they changed and
progressed across the
visible solar disk.
But contemporary observers
also regularly use this time-honored method
of monitoring sunspots.
In this sketch from March 6th 2001,
astronomer
Gunther Groenez has faithfully
recorded the intriguing shapes
and shades of major visible sunspot groups
and labeled them according to their NOAA
active region number.
Solar north is up and east to the right.
Groenez' technical equipment includes H and 2H pencil leads for the
sunspot umbra (dark) and penumbra (light) areas respectively.
Want to draw sunspots too?
Now's
your chance as two large sunspot groups are
presently making their way
across the solar disk.
Activity associated with these large sunspots may trigger
aurora
in the coming days.
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.