The International Occultation Timing Association


Information Site for Lunar Occultations & Grazes

Last Updated 18 OCTOBER 2023
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  • We encourage, promote and facilitate the observation of occultations and eclipses
  • We provide predictions for grazing occultations of stars by the Moon
    and predictions for occultations of stars by asteroids and planets
  • We also provide information on observing equipment and techniques,
    and we report to our members about observations made

  • To promote scientific research and discovery using occultation related methods
  • To conduct research at the local, regional and international level
    and to publish results of studies in popular and scientific journals
  • To stimulate public awareness of astronomical phenomena such as (but not limited to) solar and lunar eclipses and occultations of stars by minor planets, the Moon, and other solar system bodies
  • To improve lunar profile data through timing of grazing and total occultations
  • To determine shapes and sizes of minor planets and comets through timing of occultations of stars by these objects
  • To discover evidence of new, and confirm characteristics of previously discovered, satellites/companions of minor planets

The Value of Lunar Occultation Timings and Observations

Worldwide Upcoming Bright Star Occultation Events

Observers are encouraged to download the Occult software
to generate predictions for their areas, of fainter occultations

Check "Regional Information on Events" below for more information on occultation/graze events for local circumstances

How to read the country codes and prediction format

07 Oct - Occultation of ι Gem - 3.8m - s Africa
18 Oct - Occultation of σ Sco - 2.9m - se Asia
18 Oct - Occultation of α Sco - 1.1m - Middle East, e Europe
22 Oct - Occultation of 59 Sag - 4.5m - Canada, USA, Mexico
30 Oct - Occultation of η Tau - 2.9m - e Australia
30 Oct - Occultation of 27 Tau - 3.6m - Australia
06 Nov - Occultation of η Leo - 3.5m - French Polynesia
09 Nov - Occultation of η Vir - 3.9m - ne Asia, n Alaska
09 Nov - Occultation of Venus - -4.4m - Europe
14 Nov - Occultation of α Sco - 1.1m - Canada, USA, Mexico
17 Nov - Occultation of τ Sag - 3.3m - nw Australia, Indonesia
04 Dec - Occultation of η Leo - 3.5m - s Africa, Madagascar
07 Dec - Occultation of η Vir - 3.9m - Europe, Middle East, w Asia

2023 Predictions

Concerning 2023 IOTA Predictions Must Read(pdf format)
2023 Worldwide Total Occultations of Bright Stars
2023 Occultation of Planets by the Moon
2023 Total Occultations of Bright Stars for 40 North American Cities
2023 North America Graze Tables and Maps - D. Dunham
Eclipse Maps and Weather
Eclipse Information from

Asteroid Occultation Information

Steve Preston's World Wide Prediction Site
Derek Breit's Regional Asteroid Path Maps for USA
North American Asteroidal Reference Homepage
Asteroidal Occultation Results for North America
Worldwide Results Home Page
Report Form For Asteroid Observations
Japanese Astroidal Prediction Site (Japanese)
Japanese Astroidal Results (English)

Lunar Impacts and IOTA

NASA/Marshall main lunar impacts Web site
B. Cudnik's ALPO lunar meteor impacts Web site
D. Dunham's Impact Page (historical, 1999 & 2001, & earlier efforts)

Helpful Information

I.O.T.A.'s Primary Site
I.O.T.A. Membership Application - Discussion Maillist
"Chasing the Shadow: The IOTA Occultation Observer's Manual
The Occultation Observer's Handbook by Robinson & Povenmire
NWS Current Weather & Forecasts
Time Conversion Tables - UTC to Local for USA
World Time Zone Map
IOTA Annual Meeting Minutes

Occult Software and Related Information

Occult Prediction Software
Tips for using Occult by David Dunham (pdf file)
Lunar Report Generator
Occult/IOTA - Discussion Maillist
How to Use Occult 4 to Predict Comet Occultations
The ZC Star Catalog (not to be interfaced with Occult)
Expanded Site Files (updated file on 21 Aug 2023)

OccultWatcher Software

Basics of Total Occultations

Basic Information and How to Obtain Predictions
BeeperSync - An Alternative WWV Internet Based Timing Source
How to Report Observations
The Prediction Format for Total Occultations - [pdf format]
The Value of Total Lunar Occultations
Timing & Location Accuracies for Observations

Basics of Grazing Occultations

The Grazing Occultation
IOTA Standard Stations
North American city coordinates
Archive of Observed Graze Profile Reductions

Regional Information on Events - (external links)

Mid-Atlantic Occultations - D. Dunham
Kansas-Missouri Area - R. Sandy
Upper Midwest- MN, IA, ND, SD and WI
San Francisco Bay Area - D. Breit
Houston Area - P. Maley
Occultations for Belgium, France, Spain, and Portugal - J. Schwaenen
Central America/South America (in Spanish)
Brazil by Breno Loureiro Giacchini (in Portuguese)

If you have a local URL for your area, send information to the webmaster for inclusion

Use of Video on Timing Events

A Light Weight Portable Video Setup - by R. Nugent
Richard Nugent's System - by D. Dunham
Tom Heisey's Video Setup (PDF)
"Millisecond Video Timing for the Masses" by S. Herchak
Finding Limiting Mag for Visual/Video Camera Observations

KIWI-OSD and IOTA-VTI Time Inserters

LiMovie measurement tool for video occultations (the most stable version)

Miscellaneous Stuff
I.O.T.A. Tax Information/Expense Report [pdf format]
Additional Reference Reading Material


astronomy and space links, shortcuts, favorites and bookmarks.

This site maintained for IOTA by Rob Robinson, Bonner Springs KS
Send comments and mail to Webmaster
Send comments and mail to I.O.T.A. President, Steve Preston
IOTA Administration, email I.O.T.A.

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Since January 1997

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