Solar Images & Movies
Solar Images & Movies
Schematic of the solar atmosphere: the photosphere, chromosphere, and corona
The photosphere: white light images
White light image, 7/24/97 22:35 UT
Look for: limb darkening, granulation, sunspots
From: Mees Solar Observatory, White Light Telescope
[yesterday's images source, MSO]
White light image (large), 8/15/97
From: Big Bear Solar Observatory [source for latest image]
Sunspots in the Photosphere
Sunspots are dark because they are cooler than the surrounding photosphere (4000K compared to 5800K)
Dark circular central region is the umbra; surrounding lighter region is the penumbra.
Usually found at latitudes between 5-40 degrees.
Sizes range from 1500 km to 50,000 km, live for weeks to months.
Magnetogram movie of rotating Sun seen in Na 5896Å light, 6/23/97 - 7/24/97
Look for: solar rotation, ...
Magnetogram image: measured magnetic field strengths assigned different colors: strongest fields (positive or negative) are assigned the lightest or darkest colors.
Compare with Ca K images: strongest magnetic fields correspond to sunspots (2000-8000 x the field strength of the Earth's magnetic field).
Q: Could you use a compass to find N on the Sun?
From: Mt. Wilson Observatory [image source]
==>find a better image, which shows dark sunspots as well
Compare the Ca K and magnetogram images for the same date (7/24/97)
Closeup of sunspot, 7/14/94
Look for: umbra, penumbra, granulation
Diameter of penumbra is 16,500 km, larger than the diameter of the Earth (diameter of Earth is 12,800 km).
Sunspots are often found in groups called active regions.
Within each group sunspots form pairs of opposite magnetic polarity.
Isolated pairs tend to line up E-W, and the orientation of the magnetic polarities is nearly uniform throughout one hemisphere of the sun, and is the opposite of that which exists in the other solar hemisphere.
This is a direct result of the underlying mechanism which controls the overall magnetic field pattern on the Sun.
From: HAO [source, HAO; slide set]
Highly active sunspot
seen in H-alpha. Main spot at left, newly-emerged spots in bright area above. Flare occurred soon afterward.
From: Big Bear Solar Observatory [source]
Waves in the penumbra of a sunspot
From: Big Bear Solar Observatory [source]
The sunspot cycle
(graph)
From: YPOP [source]
The Chromosphere
Convective cell patterns in the chromosphere are similar to those in the photosphere, but much larger: super-granulation.
The solar disk in H-alpha light (6563Å)
H-alpha image, 8/15/97;
(large version)
From: Big Bear Solar Observatory [source for latest image]
High resolution H-alpha closeup, 7/27/97
From: Big Bear Solar Observatory [source for latest image]
Movie of rotating Sun seen in H-alpha light over the period 6/23/97 - 7/24/97
Look for: solar rotation, ...
From: Big Bear Solar Observatory [SOHO frames movie - slow to load]
Spicules
Spicules
at the Sun's limb, seen in H-alpha. Some spicules extend to heights of more than 7000 km
From: Big Bear Solar Observatory [source]
He II 304Å observation of macrospicule, Sept. 6 1996 (32 min)
Look for: Spicules, granulation
From: SOHO EIT [frames movie]
Spicules at the limb of the Sun, seen in offband H-alpha (10 minutes)
From: Big Bear Solar Observatory [source]
The solar disk in broadband Ca K light (centered at 3933Å)
Ca K line is magnetically sensitive; shows magnetically active regions.
Bright areas are "plages", usually surrounding sunspot groups.
Calcium K-line image, 8/15/97
From: Big Bear Solar Observatory [source for latest image]
See also: Mees Solar Observatory [yesterday's Ca K-Line images source, MSO]
The Corona
The shape of the corona is determined by the structure of the magnetic field, and extends far out into space.
Free electrons which move in the magnetic field of the Sun emit light.
Emission wavelengths extend from radio through X-ray.
X-ray images must be taken above the Earth's atmosphere.
Total solar eclipse showing the Sun's corona. big version
From: Steve Albers,caption APOD [source]
The Sun's corona, Jan - August 1997
From: {MK3 Coronameter, MLSO) [source, updated weekly]
The Sun in Ultraviolet Light: the upper chromosphere & lower corona
Temperatures in the photosphere, chromosphere, transition region, and corona
(graph)
From: YPOP [source]
Ultraviolet image of the Sun
Image in Fe XII 195Å obtained on 1996 August 22 at 20:15 UT.
In addition to the post-flare
loops and prominence (in absorption) on the East limb, many features
typical of the EUV corona are visible, including polar and transequatorial
coronal holes, polar plumes, ephemeral active regions, and filament
channels.
[Adapted from EIT caption]
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [source]
The relatively quiet Sun seen in the light of ionized He (He II, 304Å)
on May 18, 1996
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [APOD source]
The relatively quiet Sun seen in the light of ionized Fe (Fe IX/X, 171Å)
on May 18, 1996
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [source]
Compare the 171Å and 304Å images
(May 18, 1996)
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [source]
Compare the H-alpha, 171Å and 304Å images (May 18, 1996)
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [source], Big Bear
Ultraviolet image of the Sun
The Sun's outer atmosphere as it appears in ultraviolet light emitted
by electrically charged oxygen flowing away from the Sun to form the
solar wind (region outside black circle), and the disk of the Sun in
light emitted by electrically charged iron at temperatures near two
million degrees Celsius (region inside circle). This composite image
taken by two instruments (UVCS, outer region and EIT, inner region)
aboard the SOHO spacecraft shows dark areas called coronal holes at the
poles and across the disk of the Sun where the highest speed solar wind
originates. UVCS has discovered that the oxygen atoms flowing out of
these regions have extremely high energies corresponding to
temperatures of over 200 million degrees Celsius and accelerate to
supersonic outflow velocities within 1.5 solar radii of the solar
surface. The structure of the corona is controlled by the Sun's
magnetic field which forms the bright active regions and the ray-like
structures originating in the coronal holes. The composite image allows
one to trace these structures from the base of the corona to millions
of kilometers above the solar surface.
Adapted from EIT caption
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [source]
The rotating Sun seen in He II 304Å light over the period 6/26/97 - 7/25/97
Look for: solar rotation, granulation, solar activity
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [SOHO frames movie - slow to load]
The rotating Sun seen in Fe IX/X 171Å light over the period 6/26/97 - 7/25/97
Look for: solar rotation, lower corona, solar activity
From: SOHO Extreme-ultraviolet Imaging Telescope (EIT) [SOHO frames movie - slow to load]
The Corona in X-Ray Light
Only very hot gases emit X-rays. The disk of the Sun, at only 6000C, is too cool to produce X-rays, and appears black in these photos.
The Sun's atmosphere, on the other hand, is a good X-ray emitter (millions of degrees C), and appears bright.
Both the shape and temperature of the hot coronal gases are dictated by the Sun's magnetic field.
The Sun seen in X-ray light
on May 8, 1992
From: Yokoh satellite [source]
Changes in the Sun's X-ray output over the 11-year solar cycle
: Sept.28, 1991 (high mag. activity) and April 7, 1995 (low mag. activity)
From: Yokoh satellite [source]
The rotating Sun seen in soft X-rays over the period 6/27/97 - 7/26/97
Look for: solar rotation, ...
Step through frames 9-18 & look for changes in central spot group.
From: Yohkoh [SOHO frames movie - slow to load]
The rotating Sun seen in soft X-rays over the last few days
Look for: solar rotation, ...
From: Yohkoh SXT [source, recent data]
Sun Diver
Solar flyby in X-ray light
From: Yohkoh [source]
The Active Sun
"Seahorse flare"
seen face-on in H-alpha light, August 7 1972. Bright H-alpha loops connect two ribbons of material
From: Big Bear Solar Observatory [source]
Small quiescent prominence
at the edge of the Sun, 1970. Photographed by Big Bear's janitor when the observers called in sick.
From: Big Bear Solar Observatory [source]
Solar flare, July 14 1996
From: Big Bear Solar Observatory [source]
Solar eruption April 22, 1996, recorded with CCD through narrowband H-alpha filter
From: Big Bear Solar Observatory [source]
Erupting prominance at the limb of the Sun, August 18, 1995
From: Big Bear Solar Observatory [source]
Christmas '96 coronal mass ejection (CME)
From: SOHO LASCO C3 [source]
Same, from LASCO C2 (smaller field of view - 8.4 million kilometers)
Look for: Sun moving in front of galactic center, sungrazing comet, coronal mass ejection
From: SOHO LASCO C2 [source]
These images show the inner streamer belt along the Sun's equator, where the low
latitude solar wind originates and is accelerated. Over the polar
regions, one sees the polar plumes all the way out to the edge of the
field of view. This movie shows Comet SOHO-6, one of seven sungrazers
discovered so far by LASCO, as its head enters the equatorial solar
wind region. It eventually plunged into the Sun.
[Adapted from LASCO caption]
Solar flare in 1973. One of the largest solar flares ever recorded, captured in this Skylab image big version
From: Skylab [APOD source]
Coronal mass ejection of Jan. 15, 1996
From: SOHO LASCO [source]
Coronal mass ejection of April 7, 1997
From sequence of images recorded by the LASCO C2 coronagraph showing the big
coronal mass ejection of April 7, 1997 (see also EIT image eit022.gif
and the special page of the April 7-9 event at
http://www-istp.gsfc.nasa.gov/istp/cloud_apr97). A coronagraph is a
device to observe the faint outer solar atmosphere by blocking out the
brightness of the sun itself. The circle in the images shows where the
sun would be if it wasn't blocked out. The first frame shows the corona
just before the eruption. The first stage of the eruption is seen in
the upper right-hand corner. The eruption proceeds into a "halo"
event: in the fourth image one can see a brightening around the entire
sun, instead of in just one direction. Material ejected in this event
reached the Earth in the night of April 10-11. A significant amount of
geomagnetic activity was observed in northern regions all over the
world, reaching as far south as New Hampshire and Montana.
[Adapted from LASCO caption]
From: SOHO LASCO [source]
Aurora & comet Hale-Bopp over Boston, April 10 1997 Aurora associated with the April 7 CME
From: ISTP Sun Earth connections event [source]
the Northern Lights
From: The San Francisco Exploratorium [source]
Eruptive Prominence, Sept. 4, 1995 (3 hrs 48 min)
From: MLSO/HAO Digital Prominence Monitor [source]
Prominence Eruption, Jan. 23, 1995, H-alpha disk & limb composite (1 hr 52 min)
From: MLSO/HAO Digital Prominence Monitor [source]
Eruptive Prominence, Aug. 18, 1995 (42 min)
From: MLSO/HAO Digital Prominence Monitor [source]
and simultaneous observation of
Loop/cavity CME, Aug. 18, 1995 (42 min)
Look for wave propagating through corona
From: MLSO MK3 Coronameter [source]
Wavelength Comparisons
Wavelength Fade
Fade from white light -> H-Alpha -> soft X-rays. Neat!
From: Yohkoh SXT [source]
SXT white light / x-ray movie
Comparison of X-ray to white light, x-ray activity to sunspots, differential rotation
Rotation period of the Sun is 27 days (average); 25 days at equator, 36 days at poles.
From: Yohkoh SXT [source]
SOURCES
HAO: High Altitude Observatory
MLSO: Mauna Loa Solar Observatory
MSO: Mees Solar Observatory, Haleakala, Maui
Yohkoh SXT: Movies from Yohkoh satellite Movie Samples Page
SOHO: Frames movies from SOHO Movie Theater (Solar and Heliospheric Observatory)
SOHO EIT1: Extreme Ultraviolet Imaging Telescope (EIT)
SOHO LASCO2: Large Angle and Spectromentric Coronograph (LASCO)
1Courtesy of SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA.
2Courtesy of SOHO/LASCO consortium. SOHO is a project of international cooperation between ESA and NASA.
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Last updated August 18, 1997
He II 304Å observation of macrospicule, Sept. 6 1996 (32 min)