Solar Eclipse 2009

Total Solar Eclipse 2009

Introduction

On Wednesday, July 22, 2009, a total solar eclipse is visible within a narrow corridor that travels Japan's Ryukyu Islands. A partial eclipse is seen within the much broader area, which includes most of Japan. For example, Tokyo, Japan's capital city witnesses a partial eclipse of magnitude 0.747. Although conditions of this total eclipse, i.e., the length of totality, the altitude of the Sun, and so on, are very good, weather prospects are a major concern.

The Shadow's Path

The umbra path encounters Japan's Ryukyu Island (also known as Nansei Islands) at around 10:55 (JST, Japan Standard Time which is 9 hours ahead of UT.). Yakushima, the largest island in the path is near the northern limit and experiences 3min 57s of totality. Akuseki-shima is the closest to the central line; it gets a 6min 20s total eclipse. The path also encounters the remote Japanese islands of Iwo Jima and Kitaiwo Jima. The durations of totality from the two islands are 5min 13s and 6min 34s, respectively. A partial eclipse is seen within most of Japan. A table below summarizes Japan's local times of first, second, third and forth contact. The 6th and 7th columns show the maximum eclipse magnitude and the epoch of maximum eclipse, respectively. Note that the JST listed below corresponds to the UT+9hours. The data were calculated by Ephemeris Computation Office, NAOJ.

NASA's Solar Eclipse Bulletin

For more about the 2009 total eclipse, see the NASA bulletin (http://eclipse.gsfc.nasa.gov/SEpubs/20090722/rp.html). The 86-page publication contains detailed local predictions, tables, maps, and weather prospects. The bulletins are also available online in PDF format at http://eclipse.gsfc.nasa.gov/SEpubs/bulletin.html. Additional information, updates, maps, and diagrams are available at NASA's official eclipse website: http://eclipse.gsfc.nasa.gov/eclipse.html.

Getting Weather Information

Japan Meteorological Agency <http://www.jma.go.jp/jma/indexe.html>. Japan Meteorological Agency provides forecasting services which encompass a wide range of meteorological information such as warnings and advisories further to forecasts. Daily, one-week, and seasonal weather forecasts are available via internet. See weather forecasts of Kyushu (South), Kagoshima, and Amami areas for the total eclipse. Be careful of typhoons which are the western Pacific's equivalent of hurricanes. In Japan, July is the midst of the typhoon season.

Observing Eclipse and Eye Safety

A total solar eclipse can be called as one of the most beautiful and wonderful events of nature and should not be missed. Any recording devices such as cameras or videos cannot capture or reproduce the colors, contrast, or details of this unique phenomenon.

However, observing the sun can be very dangerous if the proper precautions are not taken.

Looking directly at the smallest part of a partial eclipse, including any annular eclipse, is very dangerous and can result in retinal damage. One must be careful just before totality and particularly as the total phase ends when watching this most spectacular phenomenon. Just after the first bright spot, the photosphere, reemerges from behind the moon, it is time to look away. Be especially cautious in advising children, as young eyes are most at risk during the partial eclipse, their lens and media is most clear, and the temptation to stare great.

The radiation to the eye during the total, or dark part of the eclipse, is less than when viewing the full moon, and that is safe for viewing for many minutes. There is all this caution about viewing a solar eclipse because there are serious risks during the partial phases. The danger comes from the fact an eclipse changes the circular, too bright disk, into something interesting. In eclipse there is a shape, a black part, and the crescent remaining of the sun. The normal safety feature of eye motion is defeated by the cognitive event of having a point to fixate. The two sharp cusps are points that the eye may focus upon and now the damaging image on the retina is stopped on the most sensitive neural tissue. This short stoppage begins damage from all mechanisms, too much blue light, too much UV, and too much heat. This damage is not recoverable.The exact duration that will cause loss of sight in that area of the retina varies greatly from eye to eye. Again greatest risk is to the young eye, and least to the oldest eyes that absorb and scatter the damaging radiation.

Again, no damage or risk to the eye is involved when looking at the total solar eclipse. But the bright disk, no matter how small or partial crescent, will cause damage. To observe bright partial phases of the eclipse a projected image is safest. There are many filter options, but great caution must be exercised in selection and use of optical aids.

Links

NASA special homepage for Total Solar Eclipse of 2009 July 22

http://eclipse.gsfc.nasa.gov/SEmono/TSE2009/TSE2009.html.

Travel Info. provided by Public Relations Division, Kagoshima Prefecture

http://www3.pref.kagoshima.jp/foreign/english/

NINS, National Astronomical Observatory of Japan
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(Phone) +81-422-34-3600
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