Constellations Educational Presentation in Blue Green Illustrative Style.pptx

There are 88 constellations officially recognized by the International Astronomical Union (IAU). 36 modern constellations predominantly lie in the northern sky, while 52 are found in the southern celestial hemisphere. Most constellations (more than 40) represent animals. Many were named after humans or figures from mythology, while some depict inanimate objects.

The boundaries of the modern 88 constellations (listed below) were defined in the early 20th century. The constellation list was produced by the American astronomer Henry Norris Russell and adopted by the International Astronomical Union (IAU) at its General Assembly in Rome in May 1922.

Russell also provided three-letter abbreviations for each of the 89 constellations (the 88 modern ones and the Greek constellation Argo, which was later dropped). The constellations on Russell’s list corresponded to those listed in the Revised Harvard Photometry star catalogue (1908), published by Harvard College Observatory. The Harvard catalogue included the positions, photometric magnitudes and spectra of 9,110 stars visible to the unaided eye (mag. 6.50 and brighter) in every part of the sky.




The official boundaries of the modern constellations were drawn by Belgian astronomer Eugène Delporte and adopted by the IAU in 1928. The constellation boundaries were drawn along horizontal and vertical lines of right ascension and declination. The modern constellations were listed by Delporte in Délimitation scientifique des constellations in 1930.

Most of the modern constellations, including the zodiac constellations, have an ancient origin. The Greco-Roman astronomer Claudius Ptolemy listed 48 constellations in his Almagest in the 2nd century CE. Most of these are still in use.

The Greek constellations are associated with different figures in Greek mythology. Even though these ancient constellations were asterisms by modern definition, many of the modern constellation names and figures are the same as the ancient ones.

Only one of the Greek constellations – Argo Navis – is no longer in use. Representing the ship of Jason and the Argonauts, the ancient constellation Argo was divided into three smaller constellations by the French astronomer Nicolas Louis de Lacaille in the 18th century. The smaller constellations represent different parts of the ship and are still in use today. Carina represents the Keel of Argo Navis, Vela represents the Sails and Puppis, the Stern.


The remaining 38 constellations were created more recently. Most of them lie in the southern sky and were invisible to the ancient Greeks and Romans. They were not created until the Age of Discovery, when European navigators started charting the southern skies.

Most of these constellations are still largely unknown to observers in the northern hemisphere because they do not rise above the horizon from locations in the mid- and far northern latitudes. Similarly, some of the far northern constellations do not make an appearance in the ni

1. A Lecture Presentation CONSTELLATIONS THE UNIVERSE & ITS STARS

2. A constellation is a group of stars in the sky that forms a pattern and has a name. For example, the stars on the right are nicknamed the Big Dipper because they look like a ladle! CONSTELLATIONS

3. The Earth rotates on its axis once every 24 hours, which is why our day/night cycle is 24 hours long. Earth's rotation impacts how we view constellations. EARTH'S ROTATION

4. As the Earth rotates, your position on Earth changes relative to the stars. This phenomenon, known as diurnal motion , makes it appear as though the constellations move across the sky throughout the night, just like the Sun 'moves' from East to West each day. DIURNAL MOTION E W

5. THE VIEW FROM EARTH E W 6:oo PM 12:0o AM 6:0o AM

6. Just as the Moon orbits the Earth, the Earth orbits the Sun. It takes the Earth around 365 days to orbit the Sun, which is why our calendar year is 365 days long. Earth's orbit also affects how we view constellations. EARTH'S ORBIT

7. Throughout the year, constellations gradually shift West due to Earth's revolution around the Sun. This is called annual motion . Since the Earth faces a different direction each season, some constellations are only visible during certain times of the year. ANNUAL MOTION Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

8. One set of constellations visible along Earth's elliptical orbit belongs to the zodiac . These constellations are the foundation for zodiac signs and astrology. THE ZODIAC Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

9. Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries The months that correspond to each zodiac are based on the Sun's position relative to the zodiac constellations. For instance, the Sun faces the constellation Aries in April, so people born in (most of) April are of the Aries astrological sign. THE ZODIAC

10. EAST WEST 1:0o AM What will be the approximate position of the constellation in five hours? CHECK FOR UNDERSTANDING #1 A B D C

11. EAST WEST 1:0o AM The constellation will be in position D (approximately) after five hours because constellations appear to move from East to West in a 24 hour cycle. CHECK FOR UNDERSTANDING #1 D 6:0o AM

12. Which zodiac constellation is the sun 'in' on the diagram to the right and, given that the Sun is in Aries for most of April, what month is it on Earth? CHECK FOR UNDERSTANDING #2 Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

13. The Sun is facing Sagittarius in the diagram and it is most likely December, but it could also be November. CHECK FOR UNDERSTANDING #2 Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

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15. Major constellation URSA MAJOR URSA MINOR

16. CASSIOPEIA CEPHEUS

17. DRACO ORION

18. VISIBLE CONSTELLATION JANUARY- caelum , dorado, mensa , orion , reticulum, and taurus FEBRUARY- Auriga, camelopardalis, canis major, columba , gemini , lepus , monocerus , and pictor MARCH- cancer, canis minor, carina, , carina, lynx, puppis , pyxis, vela, and volans APRIL- antlia , chamaeleon , crater, hydra, leo , leo minor, sextans, and ursa major MAY- canes, venatici , centaurus , coma berenices , corvus , crux, musca, and virgo JUNE- bootes , Circinus, libra, lupus, ursa minor JULY- apus, ara , corona borealis, draco, Hercules, norma, Ophiuchus, Scorpius, serpens , and Triangulum australe AUGUST- corona austrina , lyra, Sagittarius, scutum, and Telescopium SEPTEMBER- aquila, Capricornus, cygnus, Delphinus, equuleus , indus , Microscopium, pavo , sagitta, and vulpecula OCTOBER- aquarius , Cepheus, grus , lacerta , octans, Pegasus, and piscis austrinus NOVEMBER- andromeda, Cassiopeia, phoenix, pisces , sculptor and Tucana DECEMBER- aries , cetus , Eridanus, fornax , horologium, hydrus , perseus , and Triangulum.