The same summer [431 B.C.], at the beginning of a new lunar month, the only time by the way at which it appears possible, the sun was eclipsed after noon. After it had assumed the form of a crescent and some of the stars had come out, it returned to its natural shape.
— Thucydides. History of the Peloponnesian War, trans. R. Crawley (1910), New York: E. P. Dutton
On October 14, 2023, an annular solar eclipse will be visible to fortunate observers in the United States, Central America, and South America along a narrow band, approximately 130 miles (209 km) wide, that will cross fifteen states from Oregon to Texas and continue southward to Brazil and the Atlantic Ocean.
Calculate local circumstances
Major U.S. Cities in the path of annularity: Eugene OR; Albuquerque, NM; Santa Fe, NM; San Antonio, TX
Use the form below to calculate the local circumstances for cities or towns in the U.S. or its territories.
Form A - U.S. Cities or Towns
Form B - Locations Worldwide
For other eclipses, try our Solar Eclipse Computer. Times are given in UT1; for help converting them to local time, see U.S. Time Zones. Notes on the local eclipse circumstances are located at the bottom of this page.
View global map and circumstances (USNO Eclipse Portal)
The USNO Eclipse Portal provides diagrams and animations showing the global circumstances and local circumstances at selected locations. The Portal is a joint effort with Her Majesty's Nautical Almanac Office (HMNAO), United Kingdom Hydrographic Office.
Times are given in UT; for help converting them to local time, see World Time Zone Map.
View global visibility map (The Astronomical Almanac)
For visibility maps of other eclipses, see Eclipses of the Sun and Moon.
View local circumstances at Natá, Panama (maximum duration of annularity on land)
Local circumstance diagram for Natá, Panama (location of maximum duration of annularity on land) from USNO Eclipse Portal.
View local circumstances in the Gulf of Parita, 8° 9' 28" N latitude and 80° 19' 20" W longitude (maximum duration of annularity)
Local circumstance diagram for the Gulf of Parita, 8° 9' 28" N latitude and 80° 19' 20" W longitude (location of maximum duration of annularity) from USNO Eclipse Portal.
General eclipse resources
Solar Eclipse Viewing Safety
Provides information about how to safely watch the eclipse
- Eclipses of the Sun and Moon
Solar and lunar eclipse visibility maps for recent and upcoming events
- Solar Eclipse Computer
Computes local circumstances for selected solar eclipses at any given location
- Lunar Eclipse Computer
Computes circumstances for selected lunar eclipses at any given location
- USNO Eclipse Portal
Provides diagrams and animations of global and select local circumstances for solar and lunar eclipses, 1501–2100
- References on Eclipses
Provides a representative survey of the available literature
The table of local circumstances gives the UT1 time of each eclipse "event" that is visible from the location. The altitude and azimuth of the Sun at each of the events is given as well. The azimuth is reckoned eastward from North. The altitude is corrected for refraction assuming standard atmospheric conditions.
The computation of Eclipse Local Circumstances is started by iteratively computing topocentric positions of the Sun and Moon to find the time of Maximum Eclipse. Another series of position computations is performed going backwards and forwards from the time of Maximum Eclipse to find the times of contacts. The solar and lunar angular diameters are calculated at each position using radius values from DE405 (Sun 696000km; Moon 1737.4 km) to determine if contact conditions have occurred. Lunar limb profiles and center of mass/center of figure corrections are not used.
After contact times have been computed, a check is made to determine if Sunrise and/or Sunset occurred during the course of the eclipse. If so, the time of Sunrise and/or Sunset is computed.
The body of the table contains the time of each contact point, the Sun's topocentric position at that time, and its Position and Vertex Angles. The time of sunrise or sunset is also noted in the table if it occurs during the eclipse. The summary at the bottom contains the Duration, Magnitude, and Obscuration.
The Position Angle of a given contact point on the solar limb is measured eastward (counterclockwise) around the solar limb, from the point on the Sun that is farthest north.
Vertex Angle is similar to Position Angle, except that it is measured from the point on the Sun that has the highest local altitude.
Duration is the amount of time from the beginning of the eclipse to the end.
Duration of Totality is the amount of time from the beginning of the central phase eclipse to the end of the central phase. For an annular solar eclipse, it will read Duration of Annularity .
Magnitude of the eclipse is the fraction of the apparent diameter of the solar disk covered by the Moon at the time of greatest phase, expressed in units of solar diameter.
Additional eclipse definitions
- the angular distance of a celestial body above or below the horizon, measured along the great circle passing through the body and the zenith. Altitude is 90° minus the zenith distance.
- the angular distance measured eastward along the horizon from a specified reference point (usually north). Azimuth is measured to the point where the great circle determining the altitude of an object meets the horizon.
- the difference between Terrestrial Time (TT) and Universal Time (UT): ΔT=TT − UT1.
- the obscuration of a celestial body caused by its passage through the shadow cast by another body.
- eclipse, solar:
- actually an occultation of the Sun by the Moon in which the Earth passes through the shadow cast by the Moon. It may be total (observer in the Moon's umbra), partial (observer in the Moon's penumbra), annular, or annular-total.
- the obscuration of one celestial body by another of greater apparent diameter; especially the passage of the Moon in front of a star or planet, or the disappearance of a satellite behind the disk of its primary. If the primary source of illumination of a reflecting body is cut off by the occultation, the phenomenon is also called an eclipse. The occultation of the Sun by the Moon is a solar eclipse.
- 1. The portion of a shadow in which light from an extended source is partially but not completely cut off by an intervening body. 2. The area of partial shadow surrounding the umbra.
- the portion of a shadow cone in which none of the light from an extended light source (ignoring refraction) can be observed.