Astronomy Picture of the Day |
APOD: 2000 January 10 - Brown Sun Bubbling
Explanation:
Our Sun may look like all soft and fluffy, but its not.
Our Sun is an extremely large ball of
bubbling hot gas, mostly
hydrogen gas.
The
above picture was taken in a
specific color of light emitted by hydrogen gas called
Hydrogen-alpha.
Granules cover the solar
photosphere surface like shag
carpet,
interrupted by bright regions containing dark
sunspots.
Visible at the left edge is a
solar prominence.
Our Sun glows because it is hot, but it is not on fire.
Fire is the rapid acquisition of oxygen,
and there is very little
oxygen on the Sun.
The energy source of our Sun is the nuclear
fusion of hydrogen into
helium deep within its core.
Astronomers are still working to understand,
however, why so few
neutrinos are
measured from the
Sun's core.
APOD: 2005 November 6 - A Sunspot Up Close
Explanation:
Why would a small part of the Sun appear slightly dark?
Visible above is a close-up picture of a
sunspot, a depression on the Sun's face that is slightly cooler and less luminous than the rest of the
Sun.
The Sun's complex
magnetic field creates this cool region by inhibiting hot material from entering the
spot.
Sunspots can be larger than the Earth
and typically last for only a few days.
This high-resolution picture also shows clearly that the
Sun's face is a bubbling sea of separate cells of
hot gas.
These cells are known as granules.
A solar granule is about 1000
kilometers across and lasts about 10 minutes. After that, many
granules end up exploding.
APOD: 2004 April 7 - The Crown of the Sun
Explanation:
During
a total solar eclipse,
the
Sun's extensive outer atmosphere or corona
is an awesome
and inspirational sight.
The subtle shades and shimmering features of the corona
that
engage the eye span a brightness range of over
10,000 to 1, making them notoriously difficult to
capture in a single picture.
But this composite of 33 digital images
ranging in exposure time from 1/8000 to 1/5 second
comes very close to
revealing the crown of the Sun in all its glory.
The
telescopic views were recorded from Side, Turkey during
the March 29 solar eclipse,
a geocentric
celestial
event that was
widely seen
under
nearly
ideal conditions.
The composite also captures a pinkish prominence extending
just beyond the upper edge of the
eclipsed
sun.
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:
EUD at
NASA /
GSFC
& Michigan Tech. U.