NASA Solar Eclipse Bulletins

NASA/TP-2007-214149: Total Solar Eclipse of 2008 August 01

4. Eclipse Resources

4.1 IAU Working Group on Eclipses

Professional scientists are asked to send descriptions of their eclipse plans to the Working Group on Eclipses of the Solar Division of the International Astronomical Union (IAU), so they can keep a list of observations planned. Send such descriptions, even in preliminary form, to:

International Astronomical Union/
Working Group on Eclipses
Prof. Jay M. Pasachoff, Chair
Williams College–Hopkins Observatory
Williamstown, MA 01267, USA

Fax: 413-597-3200
Web Site:,

The members of the Working Group on Eclipses of the Solar Division of the IAU are: Jay M. Pasachoff (USA), Chair, Iraida S. Kim (Russia), Hiroki Kurokawa (Japan), Jagdev Singh (India), Vojtech Rusin (Slovakia), Fred Espenak (USA), Jay Anderson (Canada), Glenn Schneider (USA), and Michael Gill (UK). Yihua Yan (China),, is the director of the section of solar physics of the Beijing National Astronomical Observatory and has been added to the Working Group for the 2008 and 2009 eclipses; he is in charge of the organization of the eclipse efforts in China.

4.2 IAU Solar Eclipse Education Committee

In order to ensure that astronomers and public health authorities have access to information on safe viewing practices, the Commission on Education and Development of the IAU, set up a Program Group on Public Education at the Times of Eclipses. Under Prof. Jay M. Pasachoff, the Committee has assembled information on safe methods of observing solar eclipses, eclipse-related eye injuries, and samples of educational materials on solar eclipses (see

For more information, contact Prof. Jay M. Pasachoff (contact information is found in Sect. 4.1). Information on safe solar filters can be obtained by contacting Program Group member Dr. B. Ralph Chou (

4.3 Solar Eclipse Mailing List

The Solar Eclipse Mailing List (SEML) is an electronic news group dedicated to solar eclipses. Published by British eclipse chaser Michael Gill (, it serves as a forum for discussing anything and everything about eclipses and facilitates interaction between both the professional and amateur communities.

The SEML is hosted at URL Complete instructions are available online for subscribing and unsubscribing. Up until mid-2004, the list manager of the SEML was Patrick Poitevin ( He maintains archives of past SEML messages through July 2004 on his Web site: and

4.4 The 2007 International Solar Eclipse Conference

An international conference on solar eclipses is being planned for 2007. The main objective of the gathering is to bring together professional eclipse researchers and amateur enthusiasts in a forum for the exchange of ideas, information, and plans for past and future eclipses. Previous conferences were held in Antwerp, Belgium (2000) and Milton Keynes, England (2004), the last of which had 115 delegates from 20 different countries.

The conferences are planned for years when no central eclipses occur, to avoid travel conflicts. The 2007 event is scheduled for August 24–26 at Griffith Observatory, Los Angeles, CA. The Web site for the conference (including registration information and speaker list) is:

For more about the conference, contact the organizers (Joanne and Patrick Poitevin) at:

4.5 NASA Eclipse Bulletins on the Internet

To make the NASA solar eclipse bulletins accessible to as large an audience as possible, these publications are also available via the Internet. This was made possible through the efforts and expertise of Dr. Joe Gurman (GSFC/Solar Physics Branch).

NASA eclipse bulletins can be read, or downloaded via the Internet, using a Web browser (such as Netscape, Microsoft Explorer, etc.) from the GSFC Solar Data Analysis Center (SDAC) Eclipse Information home page, or from top-level Web addresses (URLs) for the currently available eclipse bulletins themselves:

Recent bulletins are available in both “html” and “pdf” formats. All future NASA eclipse bulletins will be available over the Internet, at or before publication of each. The primary goal is to make the bulletins available to as large an audience as possible, thus, some figures or maps may not be at their optimum resolution or format. Comments and suggestions are actively solicited to fix problems and improve on compatibility and formats.

4.6 Future Eclipse Paths on the Internet

Presently, the NASA eclipse bulletins are published 18 to 24 months before each eclipse, however, there have been a growing number of requests for eclipse path data with an even greater lead time. To accommodate the demand, predictions have been generated for all central solar eclipses from 1991 through 2030. All predictions are based on j=2 ephemerides for the Sun (Newcomb 1895) and Moon (Brown 1919, and Eckert et al. 1954). The value used for the Moon’s secular acceleration is = –26 arcsec/cy2 as deduced by Morrison and Ward (1975). The path coordinates are calculated with respect to the Moon’s center of mass (no corrections for the Moon’s center of figure). The value for ΔT (the difference between Terrestrial Dynamical Time and Universal Time) is from direct measurements during the 20th century and extrapolation into the 21st century. The value used for the Moon’s mean radius is k=0.272281.

The umbral path characteristics have been predicted with a 1 min time interval compared to the 6 min interval used in Fifty Year Canon of Solar Eclipses: 1986–2035 (Espenak 1987). This provides enough detail for making preliminary plots of the path on larger scale maps. Global maps using an orthographic projection also present the regions of partial and total (or annular) eclipse. The index Web page for the path tables and maps is:

4.7 NASA Web Site for 2008 Total Solar Eclipse

A special Web site has been set up to supplement this bulletin with additional predictions, tables, and data for the total solar eclipse of 2008. Some of the data posted there include an expanded version of Tables 7, and 8 (Mapping Coordinates for the Zones of Grazing Eclipse), and local circumstance tables with additional cities, as well as for astronomical observatories. Also featured will be higher resolution maps of selected sections of the path of totality and limb profile figures for other locations/times along the path. The URL of the special TSE2008 Web site is:

4.8 Predictions for Eclipse Experiments

This publication provides comprehensive information on the 2008 total solar eclipse to the professional, amateur, and lay communities. Certain investigations and eclipse experiments, however, may require additional information that lies beyond the scope of this work. The authors invite the international professional community to contact them for assistance with any aspect of eclipse prediction including predictions for locations not included in this publication, or for more detailed predictions for a specific location (e.g., lunar limb profile and limb-corrected contact times for an observing site).

This service is offered for the 2008 eclipse, as well as for previous eclipses in which analysis is still in progress. To discuss individual needs and requirements, please contact Fred Espenak (

4.9 Algorithms, Ephemerides, and Parameters

Algorithms for the eclipse predictions were developed by Espenak primarily from the Explanatory Supplement (Her Majesty’s Nautical Almanac Office, 1974) with additional algorithms from Meeus et al. (1966), and Meeus (1989). The solar and lunar ephemerides were generated from the JPL DE200 and LE200, respectively. All eclipse calculations were made using a value for the Moon’s radius of k=0.2722810 for umbral contacts, and k=0.2725076 (adopted IAU value) for penumbral contacts. Center of mass coordinates were used except where noted. Extrapolating from 2006 to 2008, a value for ΔT of 65.3 s was used to convert the predictions from Terrestrial Dynamical Time to Universal Time. The international convention of presenting date and time in descending order has been used throughout the bulletin (i.e., year, month, day, hour, minute, second).

The primary source for geographic coordinates used in the local circumstances tables is The New International Atlas (Rand McNally 1991). Elevations for major cities were taken from Climates of the World (U.S. Dept. of Commerce 1972). The names and spellings of countries, cities, and other geopolitical regions are not authoritative, nor do they imply any official recognition in status. Corrections to names, geographic coordinates, and elevations are actively solicited in order to update the database for future eclipse bulletins.

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2008 Mar 12