Constellation

In this episode of the "I Can't Sleep Podcast," learn about how constellations came to be. They aren't fancy or that exciting, which makes it perfect for sleepy time. Prepare your mind for more useless information you'll never share with your friends because you won't remember a bit of it. Happy sleeping!

Transcript

Welcome to the I Can't Sleep podcast,

Where I read random articles from across the web to bore you to sleep with my soothing voice.

I'm your host,

Benjamin Bostor.

Today's episode is from a Wikipedia article titled,

Constellation.

A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived outline or pattern,

Typically representing an animal,

Mythological person or creature,

Or an inanimate object.

The origins of the earliest constellations likely go back to prehistoria.

People used them to relate stories of their beliefs,

Experiences,

Creation or mythology.

Different cultures and countries adopted their own constellations,

Some of which lasted into the early 20th century before today's constellations were internationally recognized.

The recognition of constellations has changed significantly over time.

Many have changed in size or shape.

Some became popular only to drop into obscurity.

Others were limited to a single culture or nation.

The 48 traditional Western constellations are Greek.

They are given as Erratus' work Phenomena and Ptolemy's Almagist,

Although their origin probably predates these works by several centuries.

Constellations in the far southern sky were added from the 15th century until the mid-18th century,

When European explorers began traveling to the southern hemisphere.

Twelve ancient constellations belonged to the zodiac,

Straddling the ecliptic,

Which the sun,

Moon and planets all traverse.

The origins of the zodiac remain historically uncertain.

Its astrological divisions became prominent circa 400 BC in Babylonian or Chaldean astronomy.

In 1922,

The International Astronomical Union,

IAU,

Formally accepted the modern list of 88 constellations.

And in 1928 adopted official constellation boundaries that together cover the entire celestial sphere.

Any given point in a celestial coordinate system lies in one of the modern constellations.

Some astronomical naming systems include the constellation where a given celestial object is found to convey its approximate location in the sky.

A Flamsteed designation of a star,

For example,

Consists of a number and the genitive form of the constellation name.

If observed through the year,

The constellations shift gradually to the west.

This is caused by Earth's orbit around our sun.

In the summer,

Viewers are looking in a different direction in space at night than they are during the winter.

Other star patterns or groups called asterisms are not constellations per se,

But are used by observers to navigate the night sky.

Asterisms may be several stars within a constellation,

Or they may share stars with more than one constellation.

Examples of asterisms include the Pleiades and Hades within the constellation Taurus,

And the false cross split between the southern constellations Carina and Vela,

Or Venus's mirror in the constellation of Orion.

Terminology The word constellation comes from the late Latin term constellatio,

Which can be translated as set of stars.

It came into use in English during the 14th century.

These terms generally refer to a recognizable pattern of stars,

Whose appearance is associated with mythological characters or creatures,

Earthbound animals or objects.

A more modern astronomical sense of the term constellation denotes one of the 88 IAU's most celebrated constellations recognized today.

Colloquial usage does not draw a sharp distinction between constellations and smaller asterisms,

Pattern of stars,

Yet the modern accepted astronomical constellations employ such a distinction.

E.

G.

The Pleiades and the Hades are both asterisms,

And each lies within the boundaries of the constellation of Taurus.

Another example is the northern asterism popularly known as the Big Dipper,

US,

Or the Plough,

UK,

Composed of the seven brightest stars within the area of the IAU-defined constellation of Ursa Major.

The southern false cross asterism includes portions of the constellations Carina and Vela,

And the summer triangle is composed of the brightest stars in the constellations Lyra,

Aquila,

And Cygnus.

A constellation or star viewed from a particular latitude on earth that never sets below the horizon is termed circumpolar.

From the North Pole or South Pole,

All constellations south or north of the celestial equator are circumpolar.

Depending on the definition,

Equatorial constellations may include those that lie between declinations 45°N and 45°S,

Or those that pass through the declination range of the ecliptic or zodiac range in between 23.

5°N the celestial equator and 23.

5°S.

Stars in constellations can appear near each other in the sky,

But they usually lie at a variety of distances away from the earth.

Since each star has its own independent motion,

All constellations will change slowly over time.

After tens of hundreds of thousands of years,

Familiar outlines will become unrecognizable.

Stars can predict the past or future constellation outlines by measuring individual stars' common proper motions,

Or CPM,

By accurate astronomy and their radial velocities by astronomical spectroscopy.

Identification Both the 88 IAU recognize constellations,

And those that cultures have recognized throughout history,

Are essentially imagined figures and shapes with only a certain basis in the actually observable sky.

Many officially recognized constellations are based in the imaginations of ancient,

Near Eastern and Mediterranean mythologies,

But the physical reality of the earth's position in the Milky Way still produces shapes that are connected by the human mind.

For instance,

Orion's belt forms a more or less visually perfect line.

H.

A.

Ray,

Who wrote popular books on astronomy,

Pointed out the imaginative nature of the constellations and their mythological artistic basis,

And the practical use of identifying them through definite images,

According to the classical names they were given.

History of the Early Constellations Lascaux Caves,

Southern France It has been suggested that the 17,

000 year-old cave paintings in Lascaux,

Southern France depict star constellations,

Such as Taurus,

Orion's belt,

And the Pleiades.

However,

This view is not generally accepted among scientists.

Mesopotamia Inscribed stones and clay writing tablets from Mesopotamia in modern Iraq,

Dating to 3000 BC,

Provide the earliest generally accepted evidence for humankind's identification of constellations.

It seems that the bulk of the Mesopotamian constellations were created within a relatively short interval from around 1300 to 1000 BC.

Mesopotamian constellations appeared later in many of the classical Greek constellations.

Ancient Near East The oldest Babylonian catalogs of stars and constellations date back to the beginning of the Middle Bronze Age,

Most notably the Three Stars Each texts and the Moulapen,

An expanded and revised version based on more accurate observation from around 1000 BC.

However,

The numerous Sumerian names in these catalogs suggest that they built on older,

But otherwise unattested Sumerian traditions of the Early Bronze Age.

The Classical Zodiac is a revision of Neo-Babylonian constellations from the 6th century BC.

The Greeks adopted the Babylonian constellations in the 4th century BC.

Twenty Ptolemaic constellations are from the Ancient Near East.

Another ten have the same stars,

But different names.

Biblical scholar E.

W.

Bollinger interpreted some of the creatures mentioned in the books of Ezekiel and Revelations as the middle signs of the four quarters of the zodiac,

With the lion as Leo,

The bull as Taurus,

The man representing Aquarius,

And the eagle standing in for Scorpio.

The biblical book of Job also makes reference to a number of constellations,

Including Ayush Beer,

Chazal Fool,

And Chema Heap,

Rendered as Arcturus,

Orion,

And Pleiades by the King James Version,

But Ayush the Beer actually corresponding to Ursa Major.

The term Maseroth translated as a Garland of Crowns is a Hapix legomenon in Job 3832,

And it might refer to the zodiacal constellations.

Classical Antiquity There is only limited information on Ancient Greek constellations,

With some fragmentary evidence being found in the works and days of the Greek poet Hesiod,

Who mentioned the heavenly bodies.

Greek astronomy essentially adopted the older Babylonian system in the Hellenistic era,

First introduced to Greece by Eudoxus of Snidus in the 4th century BC.

The original work of Eudoxus is lost,

But it survives as a versification by Herodotus,

Dating to the 3rd century BC.

The most complete existing works dealing with the mythical origins of the constellations are by the Hellenistic writer termed Pseudo-Herodothenus and an early Roman writer styled Pseudo-Hygenus.

The basis of Western astronomy as taught during Late Antiquity and until the early modern period is the Amalgist by Ptolemy,

Written in the 2nd century.

In the Ptolemaic Kingdom,

Native Egyptian tradition of anthropomorphic figures represented the planets,

Stars,

And various constellations.

Some of these were combined with Greek and Babylonian astronomical systems,

Culminating in the zodiac of Dendera.

It remains unclear when this occurred,

But most were placed during the Roman period between 2nd to 4th centuries AD.

The oldest known depiction of the zodiac showing all the known familiar constellations,

Along with some original Egyptian constellations,

Deacons,

And planets.

Ptolemies Almagist remain the standard definition of constellations in the medieval period both in Europe and in Islamic astronomy.

Ancient China Ancient China had a long tradition of observing celestial phenomena.

Non-specific Chinese star names,

Later categorized in the 28 mansions,

Have been found on oracle bones from Hanyong dating back to the middle Shang dynasty.

These constellations are some of the most important observations of Chinese sky,

Attested from the 5th century BC.

Parallels to the earliest Babylonian Sumerian star catalogs suggest that the ancient Chinese system did not arise independently.

Three schools of classical Chinese astronomy in the Han period are attributed to astronomers of the earlier Warring States period.

Constellation of the three schools were conflated into a single system by Chen Zuo,

An astronomer of the 3rd century,

Three Kingdoms period.

Chen Zuo's work has been lost,

But information on his system of constellations survives in Tang period records,

Notably by Qutan Zeta.

The oldest extant Chinese star chart dates to that period and was preserved as part of the Duhuang manuscripts.

Native Chinese astronomy flourished during the Song dynasty,

And during the Yuan dynasty became increasingly influenced by medieval Islamic astronomy.

As maps were prepared during this period on more scientific lines,

They were considered as more reliable.

A well-known map from the Song period is the Zhu Xue astronomical chart,

Which was prepared with carvings of stars on the planosphere of the Chinese sky on a stone plate.

It is done accurately based on observations,

And it shows the supernova of the year 1054 in Taurus.

Improved by European astronomy during the late Ming dynasty,

Charts depicted more stars but retained the traditional constellations.

Newly observed stars were incorporated as supplementary to old constellations in the center sky,

Which did not depict the traditional stars recorded by ancient Chinese astronomers.

Further improvements were made during the later part of the Ming dynasty by Zhu Guangqi and Johann Adam Schall von Bell,

The German Jesuit,

And was recorded in Changshan Lishu.

Traditional Chinese star maps incorporated 23 new constellations with 125 stars of the southern hemisphere of the sky based on the knowledge of Western star charts.

With this improvement,

The Chinese sky was integrated with the world astronomy.

Early Modern Astronomy Historically,

The origins of the constellations of the northern and southern skies are distinctly different.

Most northern constellations date to antiquity,

With names based mostly on classical Greek legends.

Evidence of these constellations has survived in the form of star charts whose oldest representation appears on the statue known as Pharnes Atlas,

Based perhaps on the star catalog of the Greek astronomer Hipparchus.

Southern constellations are more modern inventions,

Sometimes as substitutes for ancient constellations.

Some southern constellations had long names that were shortened to more usable forms,

E.

G.

Musca Australis became simply Musca.

Some of the early constellations were never universally adopted.

Stars were often grouped into constellations differently by different observers,

And the arbitrary constellation boundaries often led to confusion as to which constellation a celestial object belonged.

Before astronomers delineated precise boundaries,

Starting in the 19th century,

Constellations generally appeared as ill-defined regions of the sky.

Today,

They now follow officially accepted designated lines of right ascension and declination based on those defined by Benjamin Gould in Epic 1875 in his star catalog Oranometria Argentina.

The 1603 star atlas Oranometria of Johann Baer assigned stars to individual constellations and formalized the division by assigning a series of Greek and Latin letters to the stars within each constellation.

These are known today as Baer designations.

Subsequent star atlases led to the development of today's accepted modern constellations.

Origin of the Southern Constellations The southern sky below about negative 65 degrees declination was only partially catalogued by ancient Babylonians,

Egyptians,

Greeks,

Chinese,

And Persian astronomers of the north.

The knowledge that northern and southern star patterns differed goes back to classical writers who described,

For example,

The African circumnavigation expedition commissioned by Egyptian pharaoh Neco II in circa 600 BC and those of Hano the navigator in circa 500 BC.

However,

Much of this history was lost with the destruction of the Library of Alexandria.

The history of southern constellations is not straightforward.

Different groupings and different names were proposed by various observers,

Some reflecting national traditions or designed to promote various sponsors.

Southern constellations were important from the 14th to 16th centuries when sailors used the stars for celestial navigation.

Italian explorers who recorded new southern constellations included Andrea Corsalli,

Antonio Pigafetta,

And Amarico Vespucci.

Many of the 88 IAU recognized constellations in this region first appeared on celestial globes developed in the late 16th century by Petrus Plancius,

Based mainly on observations of the Dutch navigators Pieter Dirksen,

Kaiser,

And Frederik de Houdman.

These became widely known through Johann Baer's star Atlas Oranimetria in 1603.

Seventeen more were created in 1763 by the French astronomer Nicolas-Louis de Lacay,

Appearing in his star catalogue published in 1756.

Several modern proposals have not survived.

The French astronomers Pierre Lemongier and Joseph Lalande,

For example,

Proposed constellations that were once popular but have since been dropped.

The northern constellation Quadrans Morales survived into the 19th century when its name was attached to the Coandrata meteor shower but is now divided between Boutis and Draco.

88 Modern Constellations A general list of 88 constellations was produced for the International Astronomical Union in 1922.

It is roughly based on the traditional Greek constellations listed by Ptolemy in his Almagist in the second century and Aratis' work Phenomena,

With early modern modifications and additions.

Most importantly,

Introducing constellations covering parts of the southern sky unknown to Ptolemy by Petrus Plansius,

Johannes Hevelius,

And Nicolas-Louis de Lacay,

Who named fourteen constellations and renamed a fifteenth one.

De Lacay studied the stars of the southern hemisphere from 1750 until 1754,

From Cape of Good Hope when he was said to have observed more than 10,

000 stars using a 0.

5-inches refracting telescope.

In 1922,

Henry Norris Russell produced a general list of 88 constellations and some useful abbreviations for them.

However,

These constellations did not have clear borders between them.

In 1928,

The International Astronomical Union,

IAU,

Formally accepted 88 modern constellations,

With contiguous boundaries along vertical and horizontal lines of right ascension and declination developed by Eugene de Porte that together covered the entire celestial sphere.

This list was finally published in 1930.

Where possible,

These modern constellations usually share the names of their Greco-Roman predecessors,

Such as Orion,

Leo,

Or Scorpius.

The aim of this system is area mapping,

I.

E.

The division of the celestial sphere into contiguous fields.

Out of the 88 modern constellations,

Thirty-six lie predominantly in the northern sky and the other fifty-two predominantly in the southern.

The boundaries developed by de Porte used data that originated back to epoch B.

1875,

Which was when Benjamin A.

Gould first made his proposal to designate boundaries for the celestial sphere,

A suggestion on which de Porte based his work.

The consequence of this early date is that because of the precession of the equinoxes,

The borders on a modern star map such as epoch J2000 are already somewhat skewed and no longer perfectly vertical or horizontal.

This effect will increase over the years and centuries to come.

Dark Cloud Constellations The Great Rift,

A series of dark patches in the Milky Way,

Is more visible and striking in the southern hemisphere than in the northern.

It vividly stands out when conditions are otherwise so dark that the Milky Way's central region casts shadows on the ground.

Some cultures have discerned shapes in these patches and have given names to these dark cloud constellations.

Others of the Inca civilization identified various dark areas,

Or dark nebulae,

In the Milky Way as animals and associated their appearance with the seasonal rains.

Australian Aboriginal Astronomy also describes dark cloud constellations,

The most famous being the Emu in the sky,

Whose head is formed by the cul-sac,

A dark nebula,

Instead of the stars.

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Thank you very much. I have been listening to your sessions for quite a while now. With this one I was asleep within in the frst five minutes. Brilliant idea to read random Wikipedia passages.

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I really like these readings.

Another great educational and easy to fall asleep to reading. I woke up several times last night and listened to this each time hoping to hear a list of all the constellations. I still don't know if he did list them. 🤔😴😴😴

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