About Us


For questions or comments please contact:

1 (866) 680-6563 or +1 (660) 747-2100


DayStar Filters / ICSTARS
149 NW County Road OO
Warrensburg, MO 64093-7424 USA

About Us:

This website was created by Jen Winter and Fred Bruenjes, the owners of DayStar Filters.

Fred Bruenjes is the creator of Eclipse Orchestrator, a software for controlling cameras during a solar eclipse. It has a proven track record of predicting the time and appearance of an eclipse to high accuracy. Fred has been an amateur astronomer since 1986. In 2012 he discovered Comet C/2012 C2 (Bruenjes), for which he won the Edgar Wilson Award. He has had numerous Astronomy Pictures of the Day and has had photographs published in too many magazines and books to list here. An avid eclipse chaser, he has seen 9 total solar eclipses on 5 continents. Fred is a professional designer of astronomical equipment including solar filters, telescopes, cameras, and astronomical accessories.

Jen Winter has owned DayStar Filters since 2006, providing safe equipment to view the Sun any day of the year. She is a past NASA JPL Solar System Ambassador, and minor planet (37601) Vicjen is named after her. She is coauthor of Spacious Skies, and former editor of the Astronomical League's Reflector magazine. She has led thousands of eclipse chasers into the path of totality all over the world, as group leader on numerous eclipse expeditions. She has seen 10 total solar eclipses. Jen oversees production of sub angstrom solar filters, solar telescopes and accessories, as well as directing marketing and education efforts.

Notes on Prediction Accuracy:

If you observe the eclipse within a few hundred feet of the location given in our prediction, you can expect the event times to be accurate to within 2-3 seconds, and usually better than that.

Inevitably, the predictions we provide will not match those of other sources. Consider the following when judging the potential accuracy of a prediction:

How far away from your location was the prediction? A few hundred feet can make a difference, so comparing times meant for the center of your city or a different elevation above sea level can be inappropriate. A prediction stated to only the nearest minute is a red flag, as is one without consideration of elevation. Our interface allows you to see your house to confirm your position, and uses the Google Elevation API to derive your height above sea level.

How accurate is your source of time? Cell phone clocks are usually off by a few seconds but can be incorrect by up to a minute or two. Check a reliable source to be sure your clock is correct.

In which time zone are the predictions provided? We use the Google Maps Time Zone API to provide times in the actual time zone that will be in use at your location on eclipse day.

Are the times limb-corrected? The mountains and valleys on the moon make a difference of several seconds in the start and end times of totality, so always use predictions incorporating limb profiles. We use LRO profiles, the most accurate available. Predictions by others without a limb correction or using obsolete Watts profiles will be inaccurate.

How fresh is the Delta-T prediction? We regularly update our value to keep it within milliseconds. Very old sources can be off by seconds.

Are the times UT1 or UTC based? Our predictions are referenced to the civil time that everyone uses, known as UTC, and we keep the leap second count up to date. Other people present predictions based on UT1 time or fail to account for leap seconds.

Does the predictor have a track record of accuracy at past eclipses? Our prediction engine is the same used in Eclipse Orchestrator, which has proven itself to thousands of users since 2002.


Programming: Fred Bruenjes
Concept & Artwork: Jen Winter
Mapping, time zone, and elevation data by Google.
Eclipse photos by Fred Bruenjes and Jen Winter.
Besselian Elements: Fred Espenak
Circumstance algorithms: Jean Meeus and United States Naval Observatory.
Lunar elevation data by NASA Lunar Reconaissance Orbiter LOLA.
Cloud fractions by Reto Stockli, NASA's Earth Observatory, using data provided by the MODIS Atmosphere Science Team, NASA GSFC, at the suggestion of Jay Anderson.
Stars by Yale Bright Star Atlas, courtesy Yale/NASA.

(c) 2017 DayStar Instruments. HowToEclipse.com is a resource provided by Moonglow Technologies, a Daystar Instruments Company.