Saturday, January 24, 2009

Late afternoon sky spectacle

Late afternoon sky spectacle

By Charles E. Buban
Philippine Daily Inquirer
First Posted 18:57:00 01/23/2009

Filed Under: Science (general), Lifestyle & Leisure, Astronomy

MANY Filipinos will not only be welcoming the arrival of the Year of the Ox on Jan. 26 as this day marks the Chinese New Year, but will also be witnessing a unique astronomical phenomenon: partial solar eclipse.

“This will be the first of the two partial solar eclipses that will be visible here in the country. But since the partial solar eclipse will happen less an hour before sunset—at 4:55 p.m. here in Manila—those who would like to catch this phenomenon should hope for clear skies,” said James Kevin Ty, president of Astronomical League of the Philippines.

Members of the ALP will be setting up their telescopes at the Boardwalk area in Luneta to observe and take images of the partial solar eclipse.

In a partial solar eclipse, the surface of the sun is partially blocked by the moon unlike in a total eclipse when the surface of the sun is completely blocked by the moon.

“Nevertheless, it will still be interesting. Those in Davao will be a little fortunate as the partial solar eclipse will occur a bit earlier—at 4:47 p.m.—and will see the moon covering 77 percent of the sun’s disk (observers in Manila will be able to see only 62 percent of the sun blocked by the moon),” Ty informed.

The partial solar eclipse will take just a few minutes so sky watchers are advised to set up their telescopes early.

Ty said that despite the phenomenon happening very late in the afternoon, observers must never look or stare at the sun with the naked eye, much more, look at the sun through any optical device (telescopes, binoculars) without the use of special filters over the front end of the instrument.

Take great care

Ty advised sky watchers: “You must take great care when observing a solar eclipse. A serious lapse in safety could give you eye injuries and end up having permanent vision loss and blindness. Use either a filter approved for solar observing or project the sun’s image onto a screen using binoculars, a telescope or even a simple pinhole.”

Those who would not be able to join a team of sky watchers could safely observe the sun using projection viewing by following these simple steps:

• Point your binocular, telescope or even a piece of paper or cardboard with a very tiny hole in the middle at the sun, using the shadow to judge when you are exactly in line. Remember, if using a binocular, cover one of the lenses with a lens cap or any equivalent covering.

• In the case of a piece of paper or cardboard, poke a hole in paper using a pencil point. The pinhole only needs to be a couple of millimeters across and should be as round as possible. Try not to leave jagged edges if you punch the hole through cardboard or some other stiff material.

• Hold a white board a few centimeters behind the eyepiece or the pin hole until you should see a disc of light. Focus (or in the cardboard’s case, adjust the distance) until a sharp disc appears on the white board.

• In the case of telescopes or binoculars, don’t leave the instrument pointing at the sun for a long time as the heat could damage it, or someone may inadvertently look through it.

If you happen to miss this one on Monday, the next partial total eclipse will happen in the morning of July 22 (for more details, one could visit ALP webpage at http://www.astroleaguephils.org).

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