skygazing date september meteor shower amateur astronomy a subset of astronomy is a hobby whose participants enjoy studying celestial objects i...

an astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics...

longitude sometimes denoted by the greek alphabet greek letter lambda lambda coordinate c...

the aberration of light also referred to as astronomical aberration or stellar aberration is an astronomical...

in astronomy declination abbrev dec or is one of the two coordinates of the equatorial coordinate syst...

...mars planet mars and mercury planet mercury the three dots at lower left the ecliptic is the apparent path the sun traces out along the sky independent of earth s rotation in the...

astronomical year numbering is based on anno domini ad common era ce year numbering but follows normal decimal...

galileo galileo galilei february january was an italian people italian physicist...

an equinox in astronomy is the event when the sun can be observed to be directly above the equator the...

astronomy and astrophysics abbreviated as a a in the astronomical literature or else astron astrophys is a euro...

delta t delta t deltat t or dt is the time difference obtained by subtractin...

for the calendar of religious holidays and periods see liturgical year the gregorian calendar is the calendar that is used nearly everywhere in the world a modification of the julian c...

astrometry is a branch of astronomy that deals with the positions of star s and other celestial bod...

a calendar is a system for naming periods of time typically day s these names are known as calendar d...

s galilean moons in a composite image comparing their sizes and the size of jupiter great red spot visible fro...

at the summer solstice archaeoastronomy also spelled archeoastronomy is the study of ancient or traditional astronomy astronom...

a black hole is an object predicted by general relativity the singularities of gravitational collapse and co...

the equator is an imaginary circle drawn around a planet or other astronomical object at a dist...

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