The Solar Corona, photographed with a 10 cm f/10 Maksutov telephoto lens on Kodak Royal 200, exposure time about 1 second.
This first release contains only 7 pictures, all in front of the main text. More have appeared on five special pages, linked from the main text! And there will be even more in the future! | The many links related to this story are all collected at the end of the main text! |
The convenient way to follow the partial phases of an eclipse, with a telescope in eyepiece projection or with an improvised pinhole camera - unless you have to hold the pinhole...
The solar corona and a few prominences with shorter exposure times.
Left: the instrument with which the corona images were taken.
Right: an observer properly protected from the evil rays of the
eclipse :-)
The 130th Saros series had started to
produce total eclipses in 1475 and will yield its 43rd and final one
in 2232: The peak, with the longest eclipses, was already in the
17th century (with totalities of 6 1/2 minutes); now the length of
the Saros 130 eclipses was down to just 4 minutes at best. But
that is still a lot, compared to many other currently 'active' Saros
series', and the event of February 26, 1998, had other advantages,
too. While most of its path of totality didn't hit land, some of the
places that would see a totally eclipsed Sun were both easily
accessible and had excellent weather prospects. For most
professional eclipse observers and scores of amateur
astronomers and other eclipsophiles, the choice came down to
Northern Venezuela, Aruba, Curacao, Guadeloupe and Antigua.
An eclipse committee had been set up to
promote Curacao as a tourist destination for the eclipse at
international trade fairs, to prepare the local infrastructure - and
to make local entrepreneurs realize a unique market opportunity
(for the next eclipse would hit Curacao only half a millennium
later). By sheer coincidence the eclipse would take place only two
days after the end of carnival, the annual event in this
part in the world and even mentioned in the NASA Publication for
the eclipse ("sober civilization should have returned before the
Moon begins its own ceremony with the Sun"). But wouldn't the
carnival parades and parties detract from the cosmic show, some
on the eclipse committee feared.
And for some it was already more important
than carnival: When the first participants of our eventually 22-strong
German group arrived two weeks before the eclipse,
there was already a big banner greeting its fans at the Hato
airport, the newspapers were full with details about local
preparations, and the CTDB was distributing both information
leaflets and brochures (in the local language of Papiamentu, a
confusing mix of Spanish, Dutch and more) and selling eclipse t-
shirts, caps, posters and U.S.-made eclipse glasses, the latter only
of mediocre quality, however. But there were alternative sources
as well: eclipse filters could be purchased from fast food chains
and even had for almost free, provided one had collected a certain
number of "eclipse points" from the caps of bottles of a certain soft
drink.
The decision where exactly to observe the
eclipse was a tough one indeed. The center line of totality passed
right between Aruba and Curacao, so being at the
Northwesternmost tip of Curacao would have been the optimum
choice from a geometrical point of view: Here totality would last 3
minutes and 32 seconds. But here Curacao looks like Ares Vallis
on Mars or even a weirder planet - you would either sit in a dusty
desert or stand on incredibly hard and pointy coral rock.
Nonetheless the CTDB was trying to make this "Watamula" spot
(and two others in the vicinity) more livable: Big containers (from
ships) were stacked up here to protect at least some people from
the often very strong trade winds, and some basic facilities were
put in place.
Going there, however, would set one back 60
U.S. dollars, and while several hundred eclipse travellers ended up
in Watamula (most of them because they or their tour company
had booked in advance), there were plenty of alternatives. You
could have gone to one of Curacao's 40+ marvellous beaches, for
example, or position yourself in any of a dozen villages in the
Western part of Curacao (known in Papiamentu as Band' Abao).
Compared to the Sprawling mini-metropolis of Willemstad, the
island's (and the Netherlands Antilles') capital, Curacao's "Wild
West" is a different world. Being almost completely covered by
dense thorny vegetation and Kadushi cactuses, the freedom to
move away from the network of roads into this outback (called
kunuku) is limited.
Those roads, by the way, had been
miraculaously freed of nearly all their impressive potholes two
weekends before the eclipse - we wondered whether the impending
cosmic event or the approach of carnival had brought about that
activity. In any case, travelling around the Band' Abao was easier
than ever now, provided one had still gotten a rental car (they
started to run out about a week before the eclipse). The landscape
of the West turned out to be more varied than one might have
expected from the air: In some places there were true alleys with
large trees, in others swamps with mangroves, like near the
Everglades. And every few kilometers another wondrous lagoon
(with yet another accesible coral reef and all its inhabitants).
The Belgians had moved into a luxury
appartement complex and put their remarkably small equipment
on their terrasses. There was a 70 mm refractor on a small
mount, in use in exactly the same configuration since 1973 (only
once the photographic film used had been upgraded): The aim is to
record the solar corona at various polarization angles, to
determine the electron density distribution. Using the same basic
instrument for 25 years guarantees continuity, but since 1991
the Belgians are also using a CCD camera with a telephoto lens for
similar observations. This time their work will also be used to re-
calibrate the UVCS instrument on the SOHO satellite.
The U.S. expedition had rented a complete
house in Westpunt and set up several telescopes, large and small.
The 1998 expedition of the High Altitude Observatory meant the
end of an era in solar science: For the first time they didn't bring
the famous Newkirk White Light Coronal Camera with its radially
graded filter that has taken spectacular images of the full corona
during many eclipses in recent decades (and being close to that
experiment almost guaranteed clear skies, as the author
experienced :-). The special filter that allowed much light from the
faint outer corona to reach the film but blocked most of the bright
inner corona, was necessary because the brightness range across
the corona far exceeds the dynamic range of chemical film.
But now the HAO has gone electronic: A CCD
camera with 2048 x 2048 pixels (a 4096 x 4096 pixel camera
wasn't delivered in time) has replaced the film, and instead of the
radially graded filter vastly different exposure times for several
exposures will create the necessary dynamic range to capture the
whole corona and all its structures (for later combination by computer).
Other cameras in Westpunt
were directed to specific sections of the corona, to study, e.g.,
details in the polar plumes. These ray-like structures above both
poles of the sun are of so much interest to the solar physics
community that a special conference was held on them in
Guadeloupe during the week of the eclipse. In those precious
minutes the plumes would be visible even with the naked eye - and
that moment was now less than 24 hours away.
This time we knew rather precisely what to
expect: A visit to Willemstad's new internet cafe had allowed us to
peek at the SOHO LASCO C2 coronagraph's view of the corona of
Feb. 25. This was no longer the nearly pure minimum corona of
the eclipses of 1995 and 1997, when most of the activity was
restricted to the Sun's equatorial plane: Now streamers could be
seen at somewhat higher latitudes, and an especially dense area
of the corona was visible above the Southwestern limb of the Sun,
where a large sunspot groups had disappeared only days ago.
This SOHO "preview" was not just to 'cheat' on the eclipse: We also
wanted to know whether there would be major features way out of
the Sun's equatorial plane that might warrant a special alignment
of our cameras. It wasn't necessary.
February 25th, however, had been weird,
with no clouds in the morning but many forming around noon -
the eclipse might even have been compromised. Something was
not right... And then February 26th dawned - with the darkest
clouds we had seen in all the two weeks. Before we even knew it, it
actually started to rain! But at least the old pattern of bad skies in
the morning had returned - while those who had just arrived were
worried, the 'oldtimers' knew what to expect. And indeed, around
11 a.m. the skies over Westpunt rapidly cleared up and the Sun
relentlessly pounded on the observers now setting up their
equipment. Some left for a more shady place (near Playa Lagun,
with still 3'24" to expect), most stayed and coped with the heat:
Soon Nature would provide some cooling the big way.
As with every eclipse, most of the time is
spent by waiting, discovery last minute glitches in the equipment
- and looking at clocks every few minutes. Our location in Eastern
Westpunt (69o08'43" West 12o22'30" North 110 m elevation,
according to a GPS receiver) exactly coincided with the place listed
in the NASA eclipse book, and so we knew the four 'contact times'
to the second. First Contact means that the Moon just touches
the Sun: Most people were now staring intently at a large
projected image of the Sun's disk. And then the first blemish
was visible, only seconds after the predicted time of 12:40:43: The
spectacle had begun. Within minutes the 'bite' the Moon had
taken was also visible to the naked eye, even through the less-
than-perfect 'official' eclipse glasses.
Everyone is clicking away now
with one or more cameras or trying to memorize the out-of-this-
world sight with the naked eye or binoculars. Some bats are flying
around! And some weirdos in the distance burn off fireworks... A
pre-programmed beep from a timer at precisely the middle of totality helps
a lot to organize the flow of things, but one minute before Third Contact
the finite length of totality is already apparent, with the Moon
uncovering more and more of the inner corona on the Western
limb of the Sun. It is particularly bright in the Southwestern region - as
if we hadn't known that already from the SOHO views.
How had things been in other places? In
several locations on Curacao and Aruba shadow bands had been
seen, especially after the 3rd contact, and one observer even
seems to have been able to record this phenomenon on video tape -
a rare achievement. Curacao seems to have been totally clear, but
Aruba suffered from a local weather system: Only half an hour
before totality in some, minutes before it in other places the Sun had
finally been cloud-free. For 9 minutes CNN International had
broadcast live from Aruba and Curacao, albeit with no reporter on
location and switching between the two feeds all the time -
probably the most confusing eclipse live coverage ever. Some 5000
observers may have been on both these islands alone. And in the ports
of Curacao and Aruba or offshore a whole armada of eclipse cruise
ships was sighted (a U.S. astronomy publisher alone had filled
four vessels with eclipse watchers preferring the luxurious
way).
The public in the comparably affluent
Antilles seems to have enjoyed the cosmic show - and is already
wondering when and where to repeat this supposedly "once in a
lifetime" event. In contrast to many poorer places that get hit by
eclipses, substantial parts of Curacao's population could in
principle afford to travel to Europe for the 1999 "eclipse di solo":
Large numbers go there anyway for better education and work
conditions. By and large the media seem to have presented the
eclipse as a thoroughly wonderful event, only occasionally going
overboard with dire health warnings. (Exception from the rule: a
radical Christian radio station in neighboring Bonaire that
claimed that even during totality evil rays from the sun would
come around the Moon...)
In South America, the eclipse experience had
other aspects, too, as reported in the Venezuelan Week in
Review: "Members of the Wayuu indigenous community from
the Guajira desert peninsula straddling Colombia and Venezuela
said the sun and the moon were making love and should not be
disturbed. In Caracas, the eclipse cast an eerie, hazy twilight chill
over the city. People gathered on main squares, peering at the
cloudy sky while office workers looked out from windows.
Pregnant women kept away, believing that an eclipse can leave
skin spots on unborn children" - a bizarre superstition that was
also reported in news media from previous eclipses around the
world.
And finally, there was a novel kind of eclipse
voyagers out in force this time, in addition to the established
classes of luxury eclipse tourists and eclipse travellers (like us):
"Crowds of New Age hippies staged wild Caribbean beach parties
to the beat of 'techno' music," says the Venezuelan Week,
"with up to 30 disk-jockeys flown in from Western Europe..." (On
location in Curacao from Feb. 12 to March 2nd, with interviews with
many eclipse travellers from around around the world, and Espenak &
Anderson, NASA Reference Publication 1383, the
Algemeen Dagblad - Caribische Editie Feb. 12 to March
2nd, and The Daily Journal (Caracas) - Week in
Review March 2nd, 1998)
Eclipse science:
LASCO images
of the corona, leading up to eclipse day, further planned
parallel
observations with SOHO (plus a related
news
release), results from
the HAO
expedition, the
SWRI and
Williams College
(Kern's pictures), the
MSU's,
NSF's and
NCAR's plans and the
GSFC site
(plus plans
with students).
There is also the
Yohkoh view in X rays and an
animated GIF of the Earth's shadow - in the UV as seen by the UVI
instrument on the Polar spacecraft ...
Eclipse Pictures and stories:
From Bob
Yen (outstanding images: here's his
story),
Ralph Chou,
Otto Farago,
Bill Arnett,
Olivier Staiger,
E. Pauer,
R. Brodbeck,
G.
Mahlberg (wild story!),
T. Peters,
H. Studer,
J. Fakatselis (with a hi-res view of the extremely thin prominence!),
P. Arpin,
J. Leineweber,
J. Godard,
E. Strach (shadow
bands on video),
B. Brown,
W. Carlos (image processing, also incl. Kern's data),
F. Quarnstrom,
S.
Kowollik,
M. Dandrea
et al.,
B.
Nunnelee,
S. Taylor,
L. Pertuz (Colombia)An eclipse for carnival...
But why did they always call it "Saros 130",
on leaflets, on caps and t-shirts, even special beer cans? The total
solar eclipse of February 26th, 1998, was a member of the
130th Saros cycle of eclipses, all right, but certainly not a
particularly special one. Already discovered in antiquity, the Saros
series is the period of 18 years and 11 and 1/3 days after which
the relative positions of the Sun, the Earth and the Moon almost
exactly repeat themselves, leading to very similar eclipses (only
for locations 1/3 of the Earth's circumference apart, because of
the 1/3 day) - but somehow the astro-merchandise producers of
the Netherlands Antilles island of Curacao believed that "theirs"
would be somehow unique.More pictures:
Welcome to Curacao!
And thousands came: They were not to be
disappointed. Only when they wanted to leave, in particular the
small islands of Aruba and Curacao, many would later find that
the local as well as formerly respected international airlines (esp.
KLM!) would not have any more seats for them, despite timely
reconfirmations, and were unable or unwilling to come up with
solutions by themselves. Yours truly finally made it out of
Curacao, only one day late and via Venezuela and Spain (instead of
the Netherlands), to tell the story - which is otherwise a very good
one: The incompetence and rudeness of the airlines stood in stark
contrast to the preparations that e.g. the Curacao Tourism
Development Bureau (CTDB) had initiated as far back as in
1995.More pictures:
Carnival, eclipse-style
No way: The eclipse actually became
part of the carnival activities! The central float with the
carnival queen in the big parade (Gran Marcha) was given a
cosmic touch, for example, and one of the countless dance groups
could be spotted carrying dozens of Hubble Space Telescopes!
(Actually they were meant to symbolize communications
satellites, on behalf of a telecom operator, but they were clearly
modelled after the HST.) Even more eclipse-oriented was a local
parade in the West of Curacao where a substantial fraction of the
groups (often from schools) related to the eclipse. By this time,
less than a week before E day, that other event was clearly
in the back of many peoples' minds.Living on an Island: Site Testing for E day
After the dreadful lack of eclipse-related
merchandise and market ideas both at the Indian eclipse in 1995
and the Siberian one in 1997, now everything was different.
Everywhere, you could buy eclipse t-shirts ranging from the
elegant to the funny ("the eclipse will take your breath away ... but
not your thirst" said the one from the local beer brewery) to the
plain ugly. All kinds of eclipse-related artwork was on sale - and
everywhere astronomy and gastronomy were beginning to merge.
Many restaurants all over the island (nearly all of which would get
touched by the Moon's umbra) were offering special combinations
of eclipse watching and lunch, sometimes with champagne during
totality... Eclipse Science: With the Pro's in
Westpunt
South of the either forbidding or expensive
(or both) Watamula site and still experiencing 3 minutes and 30
seconds in the Moon's shadow over rolling hills was a settlement
with the imaginative name of Westpunt (west point) - which had
declared itself the official eclipse village. Here some side roads
looked inviting for setting up the observing equipment on eclipse
day. And here we also met the two professional eclipse expeditions
that had made their coming to Curacao public beforehand: a group
from the Royal Observatory of Belgium and an expedition from
the Southwest Research Institute and the High Altitude
Observatory, both from the U.S.Waiting for the Contacts
But would we see anything at all? Climate is
what you expect, weather is what you get, many astronomical
expeditions have learned in the past, and even modern satellite
imagery was no real solution. On the views of the Caribbean from
geostationary orbit, the area around Curacao had looked
cloudfree almost every day for the past year - but the island was
just a few pixels large. The past two weeks had told us the real
weather pattern: lots of clouds in the morning that dissolved by
10 to 11 a.m. and didn't come back until late at night. Locals
actually claimed that there were more clouds than normal (was
that El Nino again...?), and that the temperatures (typically 29 to
31 degrees C in daytime) were too low (we didn't agree :-). The daily
pattern looked pretty stable, fine for an eclipse at 14:12 hours
local time (18:12 UTC).More pictures:
Second Contact!
Things get really exciting only about one hour
later: 30 minutes before totality the reduction of light becomes
noticeable, the color of the light seems to change, shadows grow
sharper, as the sun shrinks to a crescent. And finally substantial
cooling of the air sets in. Many minutes before 2nd contact the
planet Venus can be seen clearly, way below the Sun towards the
West. The sky is now as cloud-free as one could have hoped, with
only a slight haze remaining (as expected for this part of the
world). No 'screen' is thus present for the Moon's umbral shadow
to project itself onto - it just gets darker and darker. And then: the
Second Contact. Actually not a point in time, but a breathtaking
process, when the crescent Sun is cut up into "Baily's Beads" by
mountains on the Moon, the inner corona becomes visible and
then the last rays from the solar surface disappear.3 1/2 Minutes in the Shadow
What happens next is perhaps the last thing
about total solar eclipses that even modern technology cannot
predict reliably: How dark or bright will the sky be once the
photosphere is covered totally? The brightness of the corona
plays a role (it varies with the solar cycle, being brightest at
maximum activity), the size of the umbra, the clarity of the
atmosphere. This time the sky over Westpunt is not as dark and
deep blue as during the 1994 eclipse in Chile (when the Sun's
activity was low and the shadow large) and probably not as bright
as in 1991 over Mexico (when the Sun was active and the shadow
large but the atmosphere full of Pinatubo aerosols) - perhaps the
situation is closest to India, 1995. The sky has remained in a light
blue, with only the inner parts of the corona really obvious and its
long streamers fading into the background.More pictures:
The Corona, the planets and the end
Still, the corona is really getting more
exciting now, moving towards the intriguing "butterfly" shape of
1983: The magnetic field of the Sun is clearly getting more
complex year by year now, even though the number of sunspots is
growing only slowly. Also still missing: lots of prominences of an exciting
size. One substantial specimen is there, however, though overlooked by
many in the excitement, which made the 'discovery' on later developped
pictures all the more surprising. Photographs would also show a strange
pink filament hovering over the Sun's North pole. And this time the solar
system has placed Mercury above and Jupiter below the dark Sun, both very
prominent and white - almost indistinguishable.More pictures:
Good-bye ...
And with a flash it's over: Baily's Beads
appear again, the corona fades rapidly, it gets bright again. In the
East the Moon's shadow can still be seen, racing away with Mach
2, as a greyish discoloration of the sky. The usual celebrations
follow, but this time the waiting for the Fourth Contact is spent
differently: While waiting for the First, I had discovered a little bar
in downtown Westpunt - with a barkeeper from Cologne,
Germany (close to where a number of our people came from).
Loaded with a reasonable number of cold bottles of the
tasty local beer (brewed with desalinated sea water) we return to
the observing site one minute before the Moon finally clears the
solar disk: another eclipse bagged from beginning to end, and in
style.
updated March 6th, 13th, 24th (many more links)
and 30th
(more details about the eclipse added, 15 more pictures linked),
April 2nd (more science added) and 6th (more links)
Links related to this and other eclipses -
This
Eclipse
(handbook),
S&T's preview and
a
graphic representation;
and Curacao
IAU
Eclipses,
Eclipses
homepageOther Reports from our expedition:
V. Mette,
U.
Schmidtmann,
U. Reimann,
B.
Brinkmann
Reports of my expeditions to earlier eclipses:
Siberia 1997 +
India 1995
1998: A major collection of reports and science results!
(also a
collection from
Venezuela and from
G. Foley).
News reports:
Jan. 11:
Fla. Today, Feb. 9:
USA Today;
ABC (travel); Feb. 19:
CNN, Feb. 23:
CNN and
ABC, Feb. 24:
CNN, Feb. 25:
ABC and
CNN, Feb. 26:
BBC, CNN,
ABC and CNN
again, Feb. 27:
ABC,
Philadelphia Inquirer and
St. Petersburg Times, Feb. 28:
Sydney Morning Herald.
The eclipse was also covered by the
Discovery
Channel (their extensive 10-part online story starts
here).
Previous live sites: Exploratorium and Eclipse.org; various pages from Curacao (here's another one) and Venezuela; the Eclipse Zone and the Earthview Eclipse Network as well as the state of the solar cycle.
Eclipse beer ..., the Algemeen Dagblad - Caribische Editie, K-Pasa Curacao.
(To be expanded further - more links, esp. to other tour reports, welcome!)