with Astronomical Themes
Worldwide Since 1970
Member Tzell Travel Group
Eclipse Tours and More
(2017 Aug. 12)
(2017 Aug. 21)
Indonesia Solar Eclipse
[2016 Mar. 9]
Australia Solar Eclipse
Queensland, Kangaroo Isl.
Norway Northern Lights Cruise
to Above Arctic Circle
[2010 March 1021]
2009 China Total
(Links available for some but some links may not work correctly)
Caribbean Cruise Eclipse
African Eclipse Safari
Transit of Venus
Italy, Athens & Crete
Hybrid Solar Eclipse
& Geology of Arizona
Egypt Treasures &
annular (solar) eclipse An eclipse of the Sun where a ring ("annulus") of sunlight is seen around the Moon because the Moon is too far away for its disk to completely hide the Sun. Partial eclipses always precede and follow the annual phase. About one-third of all solar eclipses are annular.
azimuth Angular distance measured around the horizon usually starting at north as the zero point and measured toward east. Hence, the azimuth of the four cardinal points (north, east, south and west) would be 0°, 90°, 180° and 270° respectively. See bearing.
Baily's beads Observed just before (and after) totality. Final, thin solar crescent appears broken up into string of beads due to unevenness of lunar edge.
chromosphere ("color sphere") Inner part of solar atmosphere. Appears as thin, pinkish glow around lunar edge during totality. Can be difficult to see. Glowing hydrogen gas produces reddish color.
corona Outer part of solar atmosphere. The "crowning glory" of a total solar eclipse. Appears as a white halo around lunar disk during totality. May extend out to many times solar radius.
elongation Angular distance on the sky between the Sun (usually) and another celestial object. Hence, elongation is used to give the apparent separation between the Sun and another celestial body.
first contact Instant when Moon's disk first touches the Sun's disk during a solar eclipse (partial eclipse begins). Appears as a "first bite" out of the Sun's disk. The partial phases of a total solar eclipse have a typical duration of about 1½ hours both before and after totality. See also last contact.
kelvin (K) The SI (Système International or International System) unit of temperature. One kelvin (K) is the same temperature interval as one degree on the Celsius (Centigrade) scale. The Kelvin scale, however, begins at -273.16° Celsius (C). On the Kelvin scale, water freezes at 273.17 K (0° C) and boils at 373.13 K (100° C). Temperatures recorded on the Kelvin scale are not written degrees kelvin (°K) but simply as kelvin (K) without the degree symbol.
last contact (also fourth contact) Instant when Moon's disk last touches the Sun's disk during a solar eclipse (partial eclipse ends). Appears as a "last bite" out of the Sun's disk. See also first contact.
limb The extreme edge of the visible disk of a celestial object (e.g., the Moon's limb).
magnitude (solar eclipse) Fraction of the Sun's diameter covered by the Moon at moment of greatest eclipse. For example, the 1998 February 26 eclipse magnitude was 1.04 in the Caribbean Sea where the eclipse was total but only 0.37 (37%) In Gainesville, Florida, where the eclipse was partial. See also obscuration>
magnitude (stellar) The brightness of a celestial object. On a magnitude scale, the lower numbers indicate brighter objects. The naked eye limit is roughly mag. +6½ (dark, clear sky) but in a small city is probably no fainter than about magnitude +3 to +4. There are about twenty stars brighter than about magnitude 1.5. They are usually called "first magnitude" stars.
obscuration (solar eclipse) Fraction of the Sun's area covered by the Moon at moment of greatest eclipse. For example, the 1998 February 26 eclipse obscuration was 1.08 in the Caribbean Sea where the eclipse was total but only 0.26 (26%) in Gainesville, Florida, where the eclipse was partial. See also magnitude (solar eclipse).
partial (solar) eclipse An eclipse of the Sun where the Sun does not appear completely hidden because the Moon is not centrally located over the Sun. Partial phases precede all total and annular solar eclipses. About one-third of all solar eclipses are partial. See also total (solar) eclipse and annular eclipse.
penumbra (of a shadow) A partial shadowthe space between regions of complete shadow and complete illumination. During a solar eclipse, observer's in the Earth's penumbra see the Sun partially covered by the Moon (see partial solar eclipse.)
penumbra (of a sunspot) The lighter, cooler outer portion of a sunspot surrounding the umbra. Small spots may only have an umbra but not a penumbra. However, mature sunspots usually have a well developed penumbra that may cover 70% of the sunspot's area.
photosphere ("light sphere") The visible surface of the Sun or star. It is the layer of the Sun, about 500 km (300 miles) thick, that emits the light we see.
prominences Appear as small, bright, reddish, cloud and flame-like structures in the solar chromosphere and inner corona during totality. (Actual size can be many Earth diameters!) Prominences seem to peak out from edge of the Moon's edge as small, reddish flames or "tongues" after the Moon completely covers Sun.
saros The cycle of about 18 years over which a sequence of similar solar (or lunar) eclipses repeats. Any two eclipses separated by one saros cycle have similar characteristics.
second contact Instant when Moon's disk first completely covers the Sun's disk during a total eclipse. (Thus, the total phase of the eclipse begins at second contact.) See also third contact.
shadow bands A phenomenon sometimes seen briefly several minutes before and after totality as rapidly shimmering, irregular bands of shadow on the ground and walls. (A white surface helps make them more visible since shadow bands have low contrast.)
sunspots Localized regions of the Sun's surface (photosphere) where the temperature is approximately 1,500 Kelvins (about 3,000 Fahrenheit degrees) cooler than adjacent areas of the Sun's surface.
total (solar) eclipse An eclipse of the Sun where the Moon's disk is large enough to completely hide the Sun. Partial eclipses always precede and follow the period of totality when the Sun is totally obscured by the Moon. Nearly one-third of all solar eclipses are total. See also partial eclipse and annular eclipse.
umbra (of a shadow) The completely dark portion of the shadow cast by an object such as the Earth or Moon. During a solar eclipse, observer's in the Earth's umbra see the Sun completely (totally) covered by the Moon (see total solar eclipse.)
Universal Time A measure of time that forms the basis of civilian time. It is essentially Green Civil Time (GCT), the mean solar time at Greenwich (longitude 0°). Local zone time can be found by applying the zone's time difference (ZD). Examples: ZD = -5h (Eastern Standard Time, ZD = -6h (Central Standard Time, ZD = +8h (China).
RETURN TO TOP
MAKE YOUR RESERVATIONS NOW
TO EXPERIENCE THIS FASCINATING ADVENTURE WITH US!
Voyages Home About Us Escorts Contact Info Disclaimer Trip Planning Help