Index
 Shadows
 Eclipse Types
 Saros
Site Map

Acknowledgments

Information on these pages is gleaned from many eclipse sites all over the world.  Thanks to them, and especially to Fred Espenak of the Goddard Space Flight Center.  Fred has unarguably the best eclipse resource on the Internet - be sure to visit his page. Click here to go there in a new window.

Please feel free to e-mail me with any comments or criticisms.  Also, if you want any further information on the eclipses of 2001 & 2002, e-mail me.

Send me an e-mail!

All artwork for the Africlipse Logos on this web site are by kind favour of good  friends at Online Advertising,  Click here to e-mail them!

Online
Proudly South African

HOME PAGE

 Eclipse Types

Types of Solar Eclipse

There are four different types of solar eclipse, partial, annular, total and hybrid eclipses.  Each of these is dealt with on this page.

Rainbow Line

 Partial Solar Eclipses

Partial eclipses occur when the umbral shadow of the Moon does not touch the Earth and only the penumbral shadow touches the earth.  Because of this the umbral shadow will either pass over the north or south poles of the Earth.  These eclipses occur when a new Moon falls close to the outer limits of the eclipse window - i.e. early or late in the window. 

As an example, the partial eclipse of February 5, 2000 occurred in the Southern Hemisphere and was only visible from Antarctica. This partial eclipse had an eclipse magnitude of 57.9%.  This means that the Moon covered approximately 58% of the solar diameter.  This only happened for a specific spot on Earth, and at a specific time, called the time of greatest eclipse. For a partial eclipse this point always occurs on the transition between night and day, because at that point you are closest to the shadow axis. At the point and time of Greatest Eclipse you will see the partially eclipsed Sun on the horizon.

Partial eclipses will also occur on July 1 & 31 2000, in the same eclipse window. Two solar eclipses in the same window are fairly rare.  The first eclipse occurs near the South Pole and the second near the North Pole. They have magnitudes of 47.6% and 60.3% respectively.

Partial Solar Eclipse

A partial eclipse begins with “first contact”, when the Moon starts to move in front of the Sun.  At the instant of maximum eclipse, the Moon will cover the biggest part of the solar diameter possible from the observer’s location. At fourth or last contact the Moon leaves the solar disk and the eclipse is over.

A partial eclipse also occurs for any observers who are outside the path of totality or annularity during a total or annular eclipse.  The magnitude of the eclipse can vary from 0% to 99.99%, depending on where the observer is located.

 [Top]  [Annular]  [Total]  [Hybrid] 

Picture

 Annular Solar Eclipses

Annular Solar Eclipse - Copyright Frec Espanak

1994 eclipse animation courtesy of Fred Espenak and http://www.MrEclipse.com

In January, the earth is closest to the Sun and in July furthest from the Sun.  The difference in distance (and apparent size) is about 3% and is not discernible to the unaided eye.  The Moon also varies in distance from the earth by about 10% and consequently its apparent size in the sky also varies.  This means that the Moon can appear to be about 7% larger than the Sun, through to about 10% smaller.

Annular eclipses occur when the Moon appears smaller than the Sun.   If you are in the path of annularity you will see the Moon begin to cover the Sun, eventually sliding in front of the Sun leaving a small circle of Sunlight around the Moon’s disk for anything from a few seconds to up to 12 minutes.  The Moon then slowly uncovers the Sun again.

Because the Moon appears smaller than the Sun, the umbral shadow falls short of the earth's surface, and the portion of the earth’s surface experiencing annularity is described by extending the lines of the umbral path, as shown in the diagram.

As with partial eclipses, the instants of first and fourth contact refer to the beginning (ingress) and end (egress) of the lunar disk on the solar disk.  However because inside the path of annularity you are in the antumbral shadow the Moon will also begin and end movement inside the solar disk.

These instants are called second and third contact respectively.  Second contact is defined as the instant that the Moon is first entirely within the solar disk, and third contact is when the Moon begins to leave the inside of the solar disk.

Another way to put it is; at first contact the penumbra begins covering the observer and at second contact the antumbral shadow cone starts covering the observer.

Annular Solar Eclipse Diagram

Like partial eclipses, annular eclipses have an eclipse magnitude. For example, the annular eclipse of October 3, 2005 has a magnitude of 0.95759.  This means that the ratio between the angular diameter of the Moon and the Sun is 0.95759.

  At third contact the antumbra leaves the observer and at fourth contact the penumbral shadow cone leaves the observer and the eclipse is over.

Annular Contacts

The Moon therefore covers 96% of the Sun and so about 4.4% of the Sun still remains uncovered at the instant of greatest eclipse.  This is still enough to prevent significant darkening.

 [Top]  [Total]  [Hybrid]  [Partial]

Rainbow Line

 Total Solar Eclipses

Total Solar Eclipse - Copyright Fred Espanak

1999 eclipse animation courtesy of Fred Espenak and http://www.MrEclipse.com

Total solar eclipses are probably the most beautiful event that can be seen in the sky.  In a sense, astronomy comes to the observer!  Total eclipses are as different from annular eclipses as chalk is from cheese!

During a total eclipse of the Sun, the Moon appears bigger in the sky than the Sun. Therefore the bright rays of Sunlight are blocked by the Moon, and we are able to see the Sun's much fainter corona, the ONLY time when this is visible.

The nature around you will change dramatically, as it gets quite dark.

During a total eclipse of the Sun, the ONLY place to be is in the path of totality.  Anywhere else and you will miss the show!

At first contact the penumbra covers the observer and the eclipse begins.  Matters proceed very similarly to an annular eclipse, with the Moon gradually covering the Sun. 

Just before second contact, bright beads (Baily's beads) appear around the Moon's leading edge - these are caused by Sunlight finding its way through the deep valleys of the Moon.  The last burst of Sunlight before totality begins leaves just one bead, known as the “diamond ring”.  At second contact all Sunlight is cut off and the corona appears in all its magnificence.  For anything up to 7 min 31 seconds, day is turned into night, birds roost, and animals settle down for the night.  A circular Sunset horizon appears as you are engulfed by the Moon's shadow.

Total Solar Eclipse Schematic

Notice that, during a total eclipse, the Moon´s umbra reaches the Earth.

 [Top]  [Annular]  [Hybrid]  [Partial]

As the Moon completes it’s covering of the Sun, Baily’s beads appear once again.  This is third contact and the sky rapidly lightens, and nature returns to normal.  The eclipse ends at fourth contact, as the Moon’s disk no longer covers any portion of the Sun.

Rainbow Line

 Hybrid Solar Eclipses

This type of eclipse is fairly rare and is also known as an annular/total eclipse. The eclipse begins as an annular eclipse with the Moon’s umbral shadow just short of the earth’s surface.  But, because of the Earth's curvature, in the centre of the eclipse path, the Moon’s shadow is just long enough to “touch down” on the surface of the earth and the eclipse becomes total. The eclipse will remain total until near the end of the eclipse path when the shadow is once again too short to reach the surface and the eclipse once again becomes annular.  The hybrid eclipse of April 8, 2005 is such an annular/total eclipse.

These eclipses always have short duration of both the annular and the total phase. Therefore the width of the path of annularity/totality is very small.  These eclipses are also known for their beautiful displays of Baily’s beads.

 [Top]  [Annular]  [Total]   [Partial]

Hybrid Eclipse Schematic
Rainbow Line

Eclipse Contacts Explained

This diagram should help to explain what is meant by 1st, 2nd, 3rd and 4th contact in Annular and Total Solar Eclipses

Thanks to Cees Bassa for the use of the graphics on this page!

Eclipse Contacts
Rainbow Line

 [Eclipses]  [Types of Shadow]  [The Saros Cycle]

RSA Flag

This Africlipse InfoSite developed, executed and maintained by Peter Tiedt 2001-4.  Please advise me if you link to my site!

iX Webhouse

Hosting through the kindness and generosity of Ix Webhouse

This site was last updated 2004 Jul 24