AstroPlanet - This Month in Astronomy - Developer Glossary Reference

Glossary Reference
Antares	Antares is a red giant star and is the alpha star (the brightest star) of the Constellation Scorpius (The Scorpion).
Aphelion Aphelion of Earth	The Aphelion occurs when a planet is furthest to the Sun during its slightly elliptical orbit.
April	April is the fourth month in the Gregorian calendar and consists of 30 days. The month of April is derived from the Etruscan name of the goddess Venus, 'Apru'.
Aquarius	Aquarius (The Water Bearer) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. There are 3 deep sky objects that are on the Messier catalog, the Globular Cluster M2, Globular Cluster M72, and the Open Cluster M73. Also in Aquarius, is the Saturn Nebula NGC-7009 and the Helix Nebula NGC-7293.
Aries	Aries (The Ram) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Aries has a few dim deep sky objects including the galaxies NGC-697, NGC-772, NGC-972 and NGC-1156.
Asterism	A recognizable grouping of stars which is a subset of a Constellation. For Example: 'The Big Dipper' is an asterism of the Constellation Ursa Major (The Big Bear) or 'Pleiades' is an asterism in the Constellation Taurus (The Bull).
Astronomical Season Rule	This is a rule to define a Blue Moon based on the "Maine Rule," but using the actual Equinoxes and Solstices instead of the circular orbit of a fictitious mean Earth to define the seasons.
August	August is the eight month in the Gregorian calendar and consists of 31 days. The month of August was originally named 'Sextilis' meaning the 'sixth month' in Latin, from the time when the year began on March 1. Augustus Caesar renamed 'Sextilis' after himself to 'August' and gave it 31 days so he would have as many days as his predecessor's (Julius Caesar) month, July. It is said that Augustus pick the month after July for his month because that was the month that Cleopatra died.
Autumnal	Having to do with the season of Autumn. The Autumnal Equinox is the beginning of Fall.
Barley Moon	The name of the Full Moon usually in September, if the September Full Moon is not the Harvest Moon. Specifically the first Full Moon before the Autumnal Equinox (September 23 by "The Maine Rule"). Sometime known as the "Fruit Moon" or "Barley Moon."
Beaver Moon	The name of the Full Moon usually in November, if the November Full Moon is not the Hunters Moon. Specifically the second Full Moon before the Autumnal Equinox (September 23 by "The Maine Rule"). Sometimes known as the "Frosty Moon."
Beehive Cluster	The Beehive Cluster is the 44th object in the Messier Catalog and is given the designation 'M44'. The Beehive Cluster appears to the naked eye as a luminous patch in the Constellation Cancer (The Crab) and is about 1° 12' in size.
Blue Moon	A "Blue Moon" was originally defined as the 3rd Full Moon in an season where 4 Full Moons occur. This is the "Maine Rule" as it was used by the Maine Farmers' Almanac. Due to a misinterpretation in a 1946 article in Sky & Telescope of on a 1943 Sky & Telescope article, a definition emerged of a "Blue Moon" being the second Full Moon in a calendar month. This simpler and popular rule is known as the "Sky & Telescope Rule." The Maine Rule uses the circular orbit of a fictitious mean Earth to define the seasons.
Buck Moon	The name of the Full Moon usually in July. Specifically the first Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Thunder Moon" or the "Hay Moon."
Cancer	Cancer (The Crab) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. The Beehive Star Cluster (M44) can be found in Cancer.
Capricornus	Capricornus (The Sea Goat) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. The constellation is often depicted as a sea-goat, a goat with a fish's tail.
Celestial	Having to do with the heavens, the sky.
Cetus	Cetus (The Sea Monster) while not a zodiacal Constellation is close enough to the Ecliptic than planets will pass through it. Inside of Cetus you can find the spiral galaxy M77. According to mythology, Cetus was sent by Neptune to attack the shores of the kingdom of Cassiopeia and Cepheus. They chained their daughter Andromeda was to a cliff as an offering to Cetus as appeasement but was rescued by Perseus, who used the Gordon's head to turn Cetus to stone.
Cold Moon	The name of the Full Moon usually in December Specifically the first Full Moon before Yule (December 22 by "The Maine Rule"). Sometimes called the "Long Night Moon" or the "Moon before Yule."
Conjunction	An astronomical event where two celestial objects appear close to each other in the celestial sphere.
Constellation	A grouping or pattern of stars in the celestial sphere, usually representing a mythical person, animal or other object. Astronomers define constellations as areas, so that all celestial objects are located in one constellation.
Corn Moon	The name of the Full Moon usually in September, if the September Full Moon is not the Harvest Moon. Specifically the first Full Moon before the Autumnal Equinox (September 23 by "The Maine Rule"). Sometime known as the "Fruit Moon" or "Barley Moon."
Corn Planting Moon	The name of the Full Moon usually in May. Specifically the second Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Flower Moon" or the "Milk Moon."
Crab Nebula	Is a supernova remnant in the constellation Taurus. It is the 1st object in the Messier Catalog and is given the designation 'M1'. The supernova that create the Crab Nebula was observed by Arab and Chinese astronomers in 1054 and was observable in the daytime for 23 days. At the center of the Crab Nebula is a pulsar that rotates 30 times a second.
Crescent Crescent Moon	The shape of the lit portion of the moon or a planetary disk where the lit portion of the disk is less than half the disk surface. The terminator appear concave.
Crow Moon	The name of the Full Moon usually in March. Specifically the Full Moon before Ecclesiastical Vernal Equinox (March 21). Sometimes known as the "Worm Moon," "Sap Moon" or the "Lenten Moon."
December	December is the twelfth month in the Gregorian Calendar and consists of 31 days. The name of December is derived from the Latin 'decem' meaning ten. December was the tenth month when the year used to start on March 1.
Earth	Earth is the third planet from the Sun. Earth's diameter is 12,750 km and takes 365.25 days to orbit the Sun.
Easter Moon	The name of the Full Moon usually in April. Specifically the first Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Pink Moon," "Egg Moon," the "Pascal Moon" or the "Grass Moon."
Eclipse	An Eclipse occurs when one astronomical object moves into the shadow of another. The two types of eclipses of most interest to Earthlings, are Solar Eclipses when the Moon's shadow is cast across the surface of the Earth, and Lunar Eclipses where the Earth's shadow is cast onto the Moon. Lunar and Solar Eclipses usually occur two weeks from each other. Solar Eclipse always occur during a New Moon and Lunar Eclipses always occur during a Full Moon.
Ecliptic	The imaginary line across the sky representing the path of the Sun during the year. For practical purposes, it represents edge of the solar system. The Sun, Moon and all the planets, except Pluto, appear to travel along the ecliptic. The Ecliptic also intersects with the 13 zodiacal constellations.
Egg Moon	The name of the Full Moon usually in April. Specifically the first Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Pink Moon," "Pascal Moon," the "Easter Moon" or the "Grass Moon."
Elnath	Elnath is the tip of the Northern Horn of the Constellation Taurus (The Bull). Elnath is the beta star (the second brightest star) in the Constellation Taurus.
Elongation Elongation	Elongations occur when an inner planet's position, in its orbital path, is at tangent to the view from Earth. Because these inner planets are inside the Earth's orbits their positions as viewed from the Earth are never very far from the position of the Sun. When a planet is at Elongation, it is furthest from the Sun as viewed from Earth, so it's view is best at that point. There are two kinds of Elongations: The Eastern Elongation occurs when the planet is in the evening sky and the Western Elongation Occurs when a planet is in the morning sky.
Equinox	The Equinox is a point in the Earth's orbit where the tilt of the Earth lies on the same plane as the tangent of the Earth's orbit. There are two Equinoxes each year which marks the beginning of the Spring and Autumn seasons. Literally meaning 'Equal Night', Daylight and nighttime are of equal length on the Equinoxes. Like the Solstices, the Seasons between the Northern and Southern hemispheres are opposite of each other: The Vernal Equinox in the North occurs with the Autumnal Equinox in the South and visa-versa. The Equinoxes are counter pointed by the Summer and Winter Solstices.
Eta Leonis	Eta Leonis is the seventh brightest star in the constellation Leo (The Lion). Eta Leonis is a Class-A, supergiant star over 2000 light years from Earth.
Evening Star	Either Mercury or Venus, whichever is most prominent, when it appears in the evening sky after sunset.
February	February is the second month in the Gregorian calendar and usually consists of 28 days. Usually, ever four years February will have 29 days in a year known as a Leap Year. In the original Roman calendar, the Winter months of January and February were considered part of a monthless Winter period. At that time, the year began on March 1. The months of January and February were added around 700 BC by King Numa Pomplius. The name of February comes from the term 'Februltus', which means 'a righting of wrongs.' February was the time of purification rituals in ancient Rome.
Flower Moon	The name of the Full Moon usually in May. Specifically the second Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Milk Moon" or the "Corn Planting Moon."
Frosty Moon	The name of the Full Moon usually in November, if the November Full Moon is not the Hunters Moon. Specifically the second Full Moon before the Autumnal Equinox (September 23 by "The Maine Rule"). Sometimes known as the "Beaver Moon."
Fruit Moon	The name of the Full Moon usually in September, if the September Full Moon is not the Harvest Moon. Specifically the first Full Moon before the Autumnal Equinox (September 23 by "The Maine Rule"). Sometime known as the "Corn Moon" or "Barley Moon."
Full Full Moon	A Full Moon appears when the side on the moon facing Earth is completely sunlit. At this point the Moon is at Opposition to the Sun: rising as the Sun sets and setting as the Sun rises. If the Earth actually passes between the Sun and the Moon so that it's shadow passes across the Lunar surface that event would be a Lunar Eclipse. The Full Moon is typically the worse time for deep sky observing because the "moon glow" affects the dark sky.
Gemini	Gemini (The Twins) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. The primary Stars are named after the twins Castor and Pollux, who are the sons of Zeus and Leda in Greek mythology.
Gibbous Gibbous Moon	The shape of the lit portion of the moon or a planetary disk where the lit portion of the disk is more than half the disk surface. The terminator appear convex.
Grain Moon	The name of the Full Moon usually in August. Specifically the second Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Sturgeon Moon" or the "Green Corn Moon."
Grass Moon	The name of the Full Moon usually in April. Specifically the first Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Pink Moon," "Egg Moon," the "Easter Moon" or the "Pascal Moon."
Green Corn Moon	The name of the Full Moon usually in August. Specifically the second Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Sturgeon Moon" or the "Grain Moon."
Harvest Moon	The name of the Full Moon closest to the Autumnal Equinox (September 23 by "The Maine Rule").
Hay Moon	The name of the Full Moon usually in July. Specifically the first Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Buck Moon" or the "Thunder Moon."
Honey Moon	The name for the Full Moon closest to the Summer Solstice (June 22 by "The Maine Rule"). Usually in June.
Hunger Moon	The name of the Full Moon usually in February. Specifically the second Full Moon after Yule (December 22 by "The Maine Rule"). Sometimes known as the "Snow Moon."
Hunters Moon	The name of the Full Moon after the Harvest Moon.
Iota Capricorni	Iota Capricorni is the 10th brightest star in the constellation Capriconus. Lambda Aquarii is a variable G-type giant star and is approximately 216 light years from Earth.
January	January is the first month in the Gregorian calendar it consists of 31 days. In the original Roman calendar, the Winter months of January and February were considered part of a monthless Winter period. At that time, the year began on March 1. The months of January and February were added around 700 BC by King Numa Pomplius. The month of January was named for the god Janus.
July	July is the seventh month in the Gregorian calendar and consists of 31 days. The month of July was originally named 'Quintilis' meaning the 'fifth month' in Latin, from the time when the year began on March 1. Julius Caesar renamed 'Quintilis' to 'Julie' (July) in honor of his family.
June	June is the sixth month in the Gregorian calendar and consists of 30 days. The month of June is named after the Roman goddess Juno, wife of Jupiter.
Jupiter	Jupiter is the fifth planet from the Sun. Jupiter's diameter is 143,000 km and takes 11.86 years to orbit the Sun. Jupiter is named after the Roman king of gods. In Eastern Asian cultures Jupiter is also known as the 'Wood Star.'
Lambda Aquarii	Lambda Aquarii is the 11th brightest star in the constellation Aquarius. Also known as "Hydor" or "Ekkhysis", Lambda Aquarii is a variable M-type red-giant star and is approximately 392 light years from Earth.
Lenten Moon	The name of the Full Moon usually in March. Specifically the Full Moon before Ecclesiastical Vernal Equinox (March 21). Sometimes known as the "Worm Moon," "Sap Moon" or the "Crow Moon."
Leo	Leo (The Lion) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Leo contains the 'Sickle' asterism which forms the lions head and four spiral galaxies from the Messier catalog M65, M66, M95 and M96.
Libra	Libra (The Balance) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. The constellation was once part of the constellation Scorpius (The Scorpion) until it was renamed by the Romans. The names of some of the stars in Libra still carry this ancient legacy of Scorpius (Zubenelgenubi ('southern claw'), Zubeneschamali ('northern claw'), and Zubenelakrab ('scorpion's claw')). After its association with Scoprpio the stars of Libra were associated with the constellation of Virgo as the 'Scales of Justice' of the goddess Astraea (Virgo), the goddess of justice.
Long Night Moon	The name of the Full Moon usually in December Specifically the first Full Moon before Yule (December 22 by "The Maine Rule"). Sometimes called the "Cold Moon" or the "Moon before Yule."
Luna	Earth's moon is Luna. Usually referred to as "The Moon."
M35	M35 is an Open Cluster in the Constellation Gemini. It is the 35th object in the Messier Catalog and is designated as 'M35'. It is also known as 'NGC 2168'. M35 is about 2,800 light years away from Earth and has the apparent magnitude of 5.5.
Maine Rule	The rule for calculating a Blue Moon as the third Full Moon in a season with four Full Moons. It is named the "Maine Rule" from The Maine Farmers' Almanac. Seasons however are based on the circular orbit of a fictitious mean Earth defined from the Ecclesiastical Vernal Equinox (March 21) inferring Summer Solstice as June 22, Autumnal Equinox as September 23 and Winter Solstice as December 22 (Yule).
March	March is the third month in the Gregorian calendar and consists of 31 days. In ancient Rome, the year began on March 1. Around the year 45 BC Julius Caesar reform the calendar and moved the beginning of the year to January 1. The month of March is named after the Roman god of war, Mars.
Mars	Mars is the fourth planet from the Sun. Mars' diameter is 6,790 km and takes 687 days to orbit the Sun. Mars is named after the Roman god of war. In Eastern Asian cultures Mars is also known as the 'Fire Star.'
May	May is the fifth month in the Gregorian calendar and consists of 31 days. The month of May is named after the Greek goddess 'Maia', whose Roman name is 'Bona Dea' and whose festival was in May.
Mercury	Mercury is the closest planet to the Sun. Mercury's diameter is 4880 km and takes 88 days to orbit the Sun. Mercury is named after the Roman messenger god. In Eastern Asian cultures Mercury is also known as the 'Water Star.'
Milk Moon	The name of the Full Moon usually in May. Specifically the second Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Flower Moon" or "Corn Planting Moon."
Moon After Yule	The name of the Full Moon usually in January. Specifically the first Full Moon after Yule (December 22 by "The Maine Rule"). Sometimes known as the "Wolf Moon" or "Old Moon."
Moon Before Yule	The name of the Full Moon usually in December Specifically the first Full Moon before Yule (December 22 by "The Maine Rule"). Sometimes called the "Cold Moon" of the "Long Night Moon."
Morning Star	Either Mercury or Venus, whichever is most prominent, when it appears in the morning sky before sunrise.
Neptune	Neptune is usually the eight planet from the Sun although it is sometimes 9th when Pluto moves within it's orbit. Neptune's diameter is 49,500 km and takes 165 years to orbit the Sun. Neptune is named after the Roman god of the sea. Neptune was discovered on September 23, 1846 by French astronomer Urbain Le Verrier.
New New Moon	A New Moon occurs when the side on the moon facing Earth is completely in shadow. This means that the Moon and Sun are rising and setting in the same vicinity in the sky. If the Moon actually passes between the Sun and the Earth so that it's shadow passes across the Earth's surface that event would be a Solar Eclipse. New Moon is typically the very best time for deep sky observing.
November	November is the eleventh month in the Gregorian calendar and consists of 30 days. The name of November is derived from the Latin 'novem' meaning nine. November was the ninth month when the year used to start on March 1.
Occultation	Occultation is when a body (usually the Moon) passes in front of (hides) a star or planet.
October	October is the tenth month in the Gregorian calendar and consists of 30 days. The name of October is derived from the Latin 'octo' meaning eight. October was the eight month when the year used to start on March 1.
Old Moon	The name of the Full Moon usually in January. Specifically the first Full Moon after Yule (December 22 by "The Maine Rule"). Sometimes known as the "Wolf Moon" or the "Moon After Yule."
Ophiuchus	Ophiuchus (The Serpent Bearer) represents Aesculapius, the mythological healer of the sick. Ophiuchus might be considered the 13th Zodiacal Constellation. Over the centuries this constellation has move over the line known as the Ecliptic due to a wobble in Earth's rotation known as 'procession'. (The Ecliptic is the imaginary line that the Sun, Moon and all the planets except Pluto seem to move along. It represents the edge of the solar system.) Originally, the constellations Ophiuchus and Serpens were considered all part of the same 'Snake-Holder' constellation. Located inside Ophiuchus are the following interesting astronomical objects: Bernard's Star, several Messier Objects including (M9, M10, M12, M14, M19, M62, M107) and other open clusters like IC-4665, NGC-6633, also the nebula IC-4603-4604, and The Starfish galaxy (NGC-6240), a double galaxy.
Opposition Opposition	For planets outside the Earth's orbit (Mars, Jupiter, Saturn, Uranus, Neptune and Pluto), the months around Oppositions are the best time to view these. An Opposition occurs when the planet is opposite from the Sun, relative to the Earth. At Opposition the planet will rise as the Sun sets and will set as the Sun rises providing an entire night of observation. Also at Opposition the planet comes physically closest to the Earth in it's orbit so it appears as large as possible.
Orion	Orion (The Hunter) is one of the best known constellations in the sky, having an hourglass shape and the asterisms of Orion's Belt and Orion's Sword. Located in Orion's sword is one of the brightest nebula, Orion's Nebula (M42), which is a stellar nursery.
Pascal Moon	The name of the Full Moon usually in April. Specifically the first Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Egg Moon," the "Easter Moon" or the "Grass Moon."
Perihelion Perihelion of Earth	The Perihelion occurs when a planet is closest to the Sun during its slightly elliptical orbit.
Pink Moon	The name of the Full Moon usually in April. Specifically the first Full Moon after Ecclesiastical Vernal Equinox (March 21). Sometimes called the "Pascal Moon," "Egg Moon," the "Easter Moon" or the "Grass Moon."
Pisces	Pisces (The Fish) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Pisces contains a spiral galaxy known as Messier 74 (M74). Pisces is usually represented as two fish tied together by a long string.
Pleiades	Pleiades is an asterism in the Constellation Taurus (The Bull). It is the 45th object in the Messier Catalog and is given the designation 'M45'. Pleiades was known as 'The Seven Sisters' to the American Indians and called 'Subaru' to the Japanese.
Pluto	Pluto is usually the ninth planet from the Sun although it is sometimes 8th when Pluto moves within Neptune's orbit. Pluto's diameter is 2,300 km and takes 249 years to orbit the Sun. Pluto is named after the Roman god of the underworld. Pluto was discovered on February 18, 1930 by Clyde Tombaugh.
Regulus	Regulus is the alpha star (the brightest star) of the Constellation Leo (The Lion). Regulus is a 2nd magnitude (1.5) star and is about 77 light years from Earth.
Retrograde Motion	This is a phenomena where a planet appears to move West-to-East against the field of stars instead of the normal East-to-West direction. This occurs when the orbit of the Earth overtakes the orbit of the observed planet.
Rose Moon	The name of the Full Moon usually in June. Specifically the last Full Moon before the Summer Solstice (June 22 by "The Maine Rule"). Sometimes called the "Strawberry Moon."
Sagittarius	Sagittarius (The Archer) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Inside the constellation are the following features: The asterism known as 'The Teapot', The center of the Milky Way Galaxy, Messier Objects like M8 (The Lagoon nebula), M17 (The Horseshoe Nebula), M20 (The Trifid Nebula). Sagittarius is frequently envisioned as a centaur shooting an arrow toward the constellation Scorpius.
Sap Moon	The name of the Full Moon usually in March. Specifically the Full Moon before Ecclesiastical Vernal Equinox (March 21). Sometimes known as the "Worm Moon," "Lenten Moon" or the "Crow Moon."
Saturn	Saturn is the sixth planet from the Sun. Saturn's diameter is 120,500 km and takes 29.46 years to orbit the Sun. Saturn is named after the Roman god of agriculture. In Eastern Asian cultures Jupiter is also known as the 'Earth Star.'
Scorpius	Scorpius (The Scorpion) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Scorpius contain a red super giant star named Antares. Also in Scorpius are the open clusters known as the Butterfly Cluster (M6) and the Ptolemy Cluster (M7), and the globular clusters M4 and M80.
September	September is the ninth month in the Gregorian calendar and consists of 30 days. The name of September is derived from the Latin 'septem' meaning seven. September was the seventh month when the year used to start on March 1.
Serpens	Serpens (The Serpent) is the only constellation broken into two separate areas. Serpens Caput (The Serpent's Head) is locate Northwest of the constellation Ophiuchus (The Serpent Bearer) and Serpens Cauda (The Serpent's Tail) is locate to the Northeast of Ophiuchus. Originally, Serpens and Ophiuchus was considered just one 'Snake-Holder' constellation. Inside Serpens Caput is the globular cluster 'M5' (Messier 5) and inside Serpens Cauda is the Eagle Nebula, an open cluster, known as 'M16' (Messier 16) or 'NGC-6611.'
Sidereal Day	A measurement of a day base on the rotation of the Earth relative to the celestial sphere. A mean sidereal day is 23 hours 56 minutes 4.1 seconds. This is opposed to a Solar day which measures the rotation of the Earth against the position of the Sun (24 hours).
Sidereal Month	A month measured by the orbit of the moon measured against the celestial sphere. The mean sidereal month is 27 days 7 hours 43 minutes 11.5 seconds.
Sky & Telescope Rule	This is a rule for calculating a Blue Moon as the second Full Moon in a Calendar Month. This rule is named for Sky & Telescope whose 1946 article misinterpreted its own 1943 article on the definition of a Blue Moon. The original 1943 article was based on the "Maine Rule". It took 55 years for this error to be found and by then, the "Sky & Telescope" rule became popular.
Snow Moon	The name of the Full Moon usually in February. Specifically the second Full Moon after Yule (December 22 by "The Maine Rule"). Sometimes known as the "Hunger Moon."
Sol	Sol is the name of our sun, the star at the center of our solar system. It is about 4.37_10⁶ km in diameter and has a magnitude of -26.
Solstice	The Solstice is a point in the Earth's orbit where the tilt of the Earth points directly toward and away from the Sun. There are two Solstices each year: In the hemisphere where the tilt is toward the Sun, that would be the Summer Solstice for the hemisphere. In the hemisphere where the tilt is away from the Sun, that would be the Winter Solstice. The Summer Solstice is the day with the least amount of nighttime and the longest amount of daytime and marks the beginning of Summer. The Winter Solstice is the day with the longest amount of nighttime and the least amount of daytime and marks the beginning of Winter. The Solstices are counter pointed by the Vernal and Autumnal Equinoxes.
Spica	Spica is the alpha star (the brightest star) of the Constellation Virgo (The Maiden).
Strawberry Moon	The name of the Full Moon usually in June. Specifically the last Full Moon before the Summer Solstice (June 22 by "The Maine Rule"). Sometimes called the "Rose Moon."
Sturgeon Moon	The name of the Full Moon usually in August. Specifically the second Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Grain Moon" or the "Green Corn Moon."
Taurus	Taurus (The Bull) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Inside the constellation Taurus is the Crab Nebula (M1) and the star clusters Pleiades and Hyades. Also in Taurus is the bright, red, first-magnitude star Aldebaran located at the tip of one of the horns of Taurus.
Thunder Moon	The name of the Full Moon usually in July. Specifically the first Full Moon after the Summer Solstice (June 22 by "The Maine Rule"). Sometimes known as the "Buck Moon" or the "Hay Moon."
Uranus	Uranus is the seventh planet from the Sun. Uranus' diameter is 51,100 km and takes 84 years to orbit the Sun. Uranus is named after the Greek god of sky. Uranus was discovered on March 13th,1781 by Sir William Herschel, who reported it as a comet on April 26, 1781.
Venus	Venus is the second closest planet to the Sun. Venus' diameter is 12,100 km and takes 225 days to orbit the Sun. Venus is named after the Roman goddess of love. In Eastern Asian cultures Venus is also known as the 'Metal Star.'
Vernal	Having to do with the season of Spring. The Vernal Equinox is the beginning of Spring.
Virgo	Virgo (The Maiden) is a zodiacal constellation, that is, it lies across the ecliptic, an imaginary line across the sky that the Sun, Moon and all the planets except Pluto seem to move along. Inside the constellation of Virgo is a collection of galaxies in the Messier Catalog include the elliptical galaxies: M49, M59, M60, M84, M86, M87, M89, and the spiral galaxies: M58, M61 and M90. Also in Virgo is the Sombrero Galaxy known as M104. Virgo over time has been associated with many goddesses, but usually is associate with Astraea, the goddess of justice, holding the constellation Libra.
Waning Waning Moon Movie	The two week period from a Full to New Moon when the light across the surface of the moon is decreasing.
Waxing Waxing Moon Movie	The two week period from a New to Full Moon when the light across the surface of the moon is increasing.
Wolf Moon	The name of the Full Moon usually in January. Specifically the first Full Moon after Yule (December 22 by "The Maine Rule"). Sometimes known as the "Moon after Yule" or the "Old Moon."
Worm Moon	The name of the Full Moon usually in March. Specifically the Full Moon before Ecclesiastical Vernal Equinox (March 21). Sometimes known as the "Lenten Moon," "Sap Moon" or the "Crow Moon."
Xi Serpentis	Xi Serpentis is the 14th brightest star in the constellation Serpens (in the "Serpens Cauda" half of the "Serpens Caput" and "Serpens Cauda" pair). Xi Serpentis is a triple star system. Xi Serpentis A is a white-yellow F-type giant star and is approximately 105 light years from Earth.
Zodiacal Constellation	Any constellation which lays along the path of the Sun (The Ecliptic). In the 3000-year old religion of astrology, there are 12 zodiacal constellations, but do to the 10,000 year wobble of the Earth known as "precession," there are actually 13 zodiacal constellations.
Zubenelgenubi	Zubenelgenubi is the alpha star (the brightest star) of the Constellation Libra (The Balance).