The International Occultation Timing Association's Annual Meetings





    The Founding of IOTA   Annual Meetings 1983-1997                 IOTA Home Page

   North American Asteroid Occultation Program


IOTA's Annual Awards:..Homer F. DaBoll Award... David E. Laird Award...Lifetime Achievement Award


Annual Meetings Minutes:  

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
2019 2020 2021                


IOTA's annual meeting minutes were written by volunteers and IOTA's Executive Secretaries:1983,1984,1985,1987: Charles "Chuck" Herold, 1986, 1996: David Dunham, 1988,1989,1990: Gary Nealis, 1991: Joan Dunham,  1992,1993,1995: Rocky Harper, 1994: Walter V. Morgan, 1997: Rick Frankenberger, 1998-Present: Richard Nugent  

The Founding of IOTA

A history and beginnings of IOTA is covered in Chapter 12 of the free e-book, "Chasing the Shadow: The IOTA Occultation Observers Manual". IOTA was unofficially started in 1962 by David Dunham, when he made the first prediction of a grazing occultation of 5 Tau that was successfully observed by another observer Leonard Kalish near Castaic Junction, California. Following this observed graze, David Dunham began making predictions of lunar grazing occultations and over the next 12 years began sending them out regularly to hundreds of active observers worldwide who were hungry for these new types of scientifically valuable observations.

 By 1974, Dunham’s mailing list was so huge that the costs of computing predictions, photocopying instructions, and postage exceeded the budget of either his personal finances or what he felt he could obtain from any institution with which he was affiliated. So after years of resisting a formal structure, in 1974 he was compelled to start a quarterly Occultation Newsletter  (renamed Journal of Occultation Astronomy in 2010) for an annual subscription fee, which included the cost of local graze predictions. The first editor of Occultation Newsletter was Homer F. Daboll. Daboll was the person that coined the term “IOTA” as the International Occultation Timing Association. Homer F. DaBoll had a long history with IOTA right up until his death on March 10, 1990 at the age of 69 in Saint Charles, Illinois.

DaBoll was born on May 22, 1920. He was a major observer/expedition leader for numerous grazing occultations in the Chicago area spanning 3 decades, from the 1960’s to 1990. He edited Occultation Newsletter for 16 years from its first issue in 1974 thru early 1990 when health reasons forced him to pass on the Editorial duties to Dr. Joan Dunham. Members of IOTA have always held Homer DaBoll in the highest regard for his numerous contributions to occultation observations, expeditions, ON, and his many other volunteer efforts. Starting at the 2007 annual meeting, IOTA has presented the Homer F. DaBoll Award to the person that has made outstanding contributions to Occultation science. The first recipient of the 2007 Homer F. DaBoll award was David Herald of Australia.  

During the next year 1975, Dunham founded the International Occultation Timing Association (IOTA). In 1983, Paul Maley, IOTA’s Vice President secured IOTA tax exempt status as a Texas non-profit Corporation.  

By then, grazing occultations had become a staple of amateur observing along with total occultations, variable star observing, meteor watching, and comet hunting. Grazes had also been applied to geodesy, that is, precision mapping of the Earth, as well as to refining predictions of the orbital motion of the Moon (although both applications were later superseded by the advent of global positioning system satellites and by laser ranging to reflective lunar targets left by the Apollo astronauts). With unprecedented accuracy still not surpassed today even by the lunar orbiting spacecraft Clementine, grazes also helped refine maps of the polar lunar topography that can be seen in profile against the sky. They also have revealed hundreds of hitherto unknown close double stars, especially for fainter stars (8th and 9th magnitude). Today IOTA’s data base includes the results of over 3,600 grazes observed over the past four decades and over 4,000 successfully observed asteroid occultation events.

Annual Meetings 1983-1997

During the years 1983-1996 IOTA's annual meetings were held in Texas since that is where the corporation was chartered. Being scientists and not businessmen, IOTA's Officers assumed that the annual meetings were required to be held in the corporation's home state. The 1997 meeting was held in Orem, Utah. In 1998 Richard Nugent, the newly elected Executive Secretary showed that the meetings could be held anywhere. This allowed IOTA’s annual meetings to be held at locations in the USA surrounding important and spectacular occultation events. So, starting in 1998, when the annual meeting was held near Nashville, Tennessee to observe a rare triple grazing occultation, IOTA annual meetings have gone nationwide recruiting and creating interest among amateur and professional astronomers in asteroid occultations. 

    The Founding of IOTA   Annual Meetings 1983-1997         IOTA Home Page

   North American Asteroid Occultation Program

IOTA's free e-book on Occultations:   Chasing the Shadow: The IOTA Occultation Observer's Manual

IOTA's 11-page brief tutorial on occultations



The International Occultation Timing Association is the primary scientific organization that predicts, observes and analyses lunar and asteroid occultations and solar eclipses. IOTA astronomers have organized teams of observers worldwide to travel to observe grazing occultations of stars by the Moon, eclipses of stars by asteroids and solar eclipses since 1962.