The Age of the Telescope

Astronomy after the invention of the telescope

In 1610, Galileo Galilei pointed a telescope at the stars and in one instant, the universe became a lot bigger. With better telescopes, our understanding of the universe and of the forces that held it together grew exponentially.

The primary focus of this site is not astronomy, but Star Lore, which is folklore based upon stars and star patterns. We try to create a collection of mythical stories about stars and constellations from all over the world. However, to better understand the myths and legends of stars and constellations, a brief history of the development of our modern constellations might be helpful. This is by no means a scientific paper on the history of astronomy, but merely an illustrated collection of highlights of that history, along with some links to what we think are reliable sources on the subject.

Bits of the history of Astronomy after the Invention of the Telescope

Sidereus Nuncius (1610)

On March 13, 1610, Galileo Galilei published the first scientific work based on observations made through a telescope. The treatise, called Sidereus Nuncius, the Starry Messenger contained the results of Galileo's early observations of the surface of the Moon, of hundreds of stars invisible to the naked eye and the Medicean Stars that appeared to be circling Jupiter.

Later, the Medicean Stars were rename the Galilean moons.

To the right are Galileo's sketches of the Moon, The Pleiades and the Medican Stars, as the appeared in Sidereus Nuncius.

Source: Wikipedia.

Title page, Sidereus nuncius
Source: Wikipedia

Mundus Iovialis, the World of Jupiter (1614)

German astronomer Simon Marius pointed his telescope at Jupiter a month before Galileo did. He was the first to observe the Iovian Moons, but did not start taking notes until January 8, 1610, literally one day later than Galileo.

Marius published his findings in a local almanac in 1611 and then in 1614 in a book called Mundus Iovialis, the World of Jupiter. Galileo successfully accused Marius of plagiarism. The controversy was settled only 300 years later in 1907, when Marius was credited with an independent discovery of the moons.

In spite of the dispute, which tainted Marius' reputation for three decades, he still left his mark: Marius was the one who gave the Galilean moons their names.

Marius was also the first to give a scientific description of the Andromeda Galaxy based on telescopic observations.

Sources: Wikipedia, Jay M. Pasachoff, Nürnberger Astronomische Gesellschaft

Marius in Mundus Iovialis
Source: Wikipedia

Three other astronomers need to be mentioned as early users of telescopes.

In London, Thomas Harriot used his telescope even earlier than Galileo. On July 26, 1609, Harriot created the first drawing of the moon, observed by a telescope. In 1610, he was was the first to observe Sunspots.

Sunspots were also observed by Dutch astronomer Johannes Fabricius who in 1611 was the first to write about them in a pamphlet titled De Maculis in Sole.

In Paris, Nicolas-Claude Fabri de Peiresc made the first detailed observations of the Orion Nebula in November 1610.

Galileo Galilei too observed sunspots and wrote a pamphlet called Letters on Sunspots in 1613. He also continued watching the planets through his telescope. In 1616, he did a first drawing suggesting Saturn's ring system.

Sources: Wikipedia, Wikipedia

Early observations using telescopes

Harriot observing the Moon in 1609
Oil painting by Rita Greer, 2009 Source: Wikipedia
Moon, Harriot 1609
Source: Wikipedia
Orion Nebula, de Peiresc 1610
Source: Wikipedia
Sun Spots, Galilei 1613
Source: APS News
Saturn's Rings, Galilei 1616
Source: NASA

Johannes Kepler

German astronomer and mathematician Johannes Kepler is without doubt one of the greatest names in the history of astronomy and there is not enough room here to list all of his contributions.

Kepler's studies on planetary mechanics are an essential part of the Scientific Revolution of the 17th century. His idea that the Sun regulates the velocity of the planets is a milestone in scientific thought, laying the foundation for Newton's theory of universal gravitation.

Sources: Wikipedia Space Today

Astronomia Nova (1609)

Already mentioned in the previous section, published in 1609, Astronomia nova (New Astronomy), is considered one of the most significant books in the history of astronomy.

Source: Wikipedia

Epitome Astronomiae Copernicanae (1618 - 1621)

Between 1618 and 1621, Kepler published the three volumes of Epitome Astronomiae Copernicanae, which contained the first printed version of his third Law of planetary motion.

Source: Wikipedia

Harmonices Mundi (1619)

In Harmonices Mundi (The Harmony of the World), published in 1619 Kepler contemplates on the beauty in the structure of the Universe, and harmony in geometric figures, numbers and music. He also announces his third law of planetary motion describing thea relationship between the orbital periods and the distances of the planets from the Sun.

Sources: Wikipedia, Space Today

The Rudolphine Tables (1627)

Concerning the development of star charts and constellations, Kepler published one great opus just a few years before his death in 1627, the Rudolphine Tables, dedicated to emperor Rudolf II.

Sources: Wikipedia, Wikipedia

Title page Epitome
Source: Wikipedia

Harmonices Mundi
Source: Wikipedia

2005 edition of Astronomia Nova
Source: Abe Books

Title page Rudolphine Tables
Source: Wikipedia

Mizar - the first observation of a Double Star (1617)

In 1617, Galileo Galilei and Italian astronomer Benedetto Castelli compared their notes in the observation of Mizar (ζ Ursae Majoris) concluding that is a Double Star.

Although Galileo and Castelli were the first to observe a double star, credit for the discoverey is generally given to Italian astronomer Giovanni Riccioli who wrote about the observation in his Almagestum Novum in 1651.

Source: A New view of Mizar

Galileo's notes on Mizar
Source: A New view of Mizar

Usus astronomicus planisphaerii stellati (1624)

In 1624, German astronomer Jakob Bartsch, Johannes Kepler's son-in-law, published a book titled Usus astronomicus planisphaerii stellati (Astronomical Use of the Stellar Planisphere).

The book was mainly a manual of practical astronomy, but its fold-out charts showed a number od constellations that have not been seen on star maps before or after as he introduced six constellations designed by Petrus Plancius: Camelopardalis, Monoceros, Gallus, Jordanus, Tigris and Vespa - only the first two are still in use today.

Sources: Wikipedia, Ian Ridpath

Planiglobium coeleste et terrestre (1628)

Four years later, German astronomer Isaac Habrecht II published Planiglobium coeleste et terrestre (Plates of the Heavens and the Earth), which also showed the six Plancius constellations plus the Rhombus, a now obsolete constellation invented by Habrecht II.

Sources: Wikipedia, Ian Ridpath

Bartsch’s star chart; Ian Ridpath

Planiglobium; Google Books

Eclipse Competition on the Chinese imperial court (1629)

In 1601, Italian Jesuit priest and scientist Matteo Ricci became the advisor in matters of astronomy and calendrical science to the Chinese Emperor (see here for details). In 1610, he was succeeded by Nicolò Longobardo.

In 1629, Longobardo and fellow German Jesuit pries Johann Schreck had a unique opportunity to demonstrate the latest advances in astronomy to the Emperor. Schreck had corresponded with Johannes Kepler who sent him a copy of the just finished Rudolphine Tables and a new elliptical model for the orbit of the moonn, vastly improving the predictions of eclipses.

When a solar eclipse over Beijing was predicted for June 21, 1629, the Jesuits challenged Chinese astronomers to precisely predict the time of the Event. The Jesuits won, causing the Chinese emperor to order a complete overhaul of the Chinese Calendar.

Source: Wikipedia

Nicolò Longobardo
Source: Wikipedia

The Southern Asterisms (1629)

Work on the new calendar, which would later be known as the Chongzhen Calendar was carried out by German Jesuits Johann Schreck and Johann Adam Schall von Bell, together with Chinese Jesuite Xu Guangqi, the one who started the scientific East-West collaboration with Matteo Ricci almost three decades earlier (see here for details).

In addition to the work on the new calendar, Schall von Bell and Xu Guangqi introduced the Southern Asterisms: The stars around the southern pole that could not be observed directly from China were divided into 23 asterisms and incorporated into traditional Chines astronomy.

The calendar and the Southern Asterisms earned Schall von Bell a lasting place in the history of Chinese astronomy.

Source: Wikipedia

Taiwanese stamp commemorating
Schall's 400th birthday (1992)

Galileo's Dialogue (1632)

In 1632, Galileo Galilei wrote a fictive dialog consisting of a series of discussions among two philosophers and a layman, comparing the Copernican system with the traditional Ptolemaic system.

The original title Dialogue on the Tides was censored by the Inquisition of the Roman Catholic Church, as such a title would look like approval of his theory of the tides using the motion of the Earth as proof. As a result, the formal title on the title page is Dialogo (Dialogue); later it became known as Dialogo sopra i due massimi sistemi del mondo, Dialogue Concerning the Two Chief World Systems.

Source: Wikipedia

Dialogo; Wikipedia

E pur si muove (1633)

Inspite of all the scientific breakthroughs, acceptance for the heliocentric model grew only slowly.

In 1633, Galileo's Dialogo was placed on the Index of Forbidden Books. Galileo was found to be "vehemently suspect of heresy" and was forced by the Inquisition of the Roman Catholic Church to recant his theory that the Earth moves around the Sun.

Under threat of torture, Galileo recanted. But as he left the courtroom, he is said to have muttered, E pur si muove (all the same, it moves).

Sources: Wikipedia,

Galileo before the Holy Office
Joseph-Nicolas Robert-Fleury, 1847; Source: Wikipedia

Urania Propitia (1650)

The Rudolphine tables contained the positions of the 1,005 stars measured by Tycho Brahe in his Astronomiae Instauratae Progymnasmata and over 400 stars from Ptolemy's Almagest and Johann Bayer's Uranometria.

Kepler's tables were filled with complex and tedious logarithms, which was ingenious but tiresome and hard to read. In 1650, Silesian astronomer Maria Cunitz published a simplified version of the Rudolphine Tables to make Kepler's work more accessible to the public.

Maria Cunitz' Urania Propitia stands out not only scientifically, but also historically. According to Noel Swerdlow, professor emeritus of history, astronomy and astrophysics at the University of Chicago, it is the earliest surviving scientific work by a woman on the highest technical level of its age.

Source: Wikipedia

Title page Urania Propitia
Source: ABE Books

Systema saturnium (1659)

In 1656, Dutch astronomer Christiaan Huygens, using one of the best telescopes of the time discovers Saturn's Moon Titan.

In his Systema Saturnium , published in 1659, Huygens describes the observation of Titan and confirms Galileo's theory of Saturn's Rings.

In 1695, Huygens completed Cosmotheoros, a philosophical treatise on his speculations on the construction of the universe and the habitability of the planets as deduced from his own observations and those of other astronomers. It was published posthumously in 1698.

Sources: Wikipedia, Internet Archive, The Cosmotheoros of Christiaan Huygens

Huygens' observations of Saturn
Source: Wikipedia

Edmond Halley at St. Helena (1679)

Between 1677 and 1678, famous English astronomer Edmond Halley spent a year on the small island of St. Helena to observe a solar and a lunar eclipse and a transit of Mercury across the face of the Sun. He filled the time between those observations by cataloguing as many stars of the southern sky as the cloudy weather permitted.

After his return, Halley published a catalogue called Catalogus Stellarum Australium (Catalogue of the Southern Stars).

In a subtitle, he called it Supplementum catalogi Tychonici as he considered it a supplement to Tycho Brahe's 1602 catalogue.

Sources: Wikipedia and Ian Ridpath

Halley's Catalogus

Principia - A Revolution in Physics (1687)

Sir Isaac Newton is widely recognized as one of the most influential scientists of all time and as a key figure in the scientific revolution.

In 1687, Newton laid the foundations of classical mechanics with the publication of his book Philosophiæ Naturalis Principia Mathematica.

In the Principia, Newton formulated the laws of motion and universal gravitation. His mathematical description of gravity to proved Kepler's laws of planetary motion, account for tides, the trajectories of comets, the precession of the equinoxes and other phenomena.

Newton didn't discover a new planet or describe a new constellation. But his theoretical work proved fundamental for astronomy. While Copernicus and Kepler described how the planets moved, Newton was the first to explain why.

Another important contribution to astronomy was the reflecting telescope, built by Newton in 1668. The device was first described in 1663 by Scottish astronomer James Gregory.

Source: Wikipedia

Title page of Principia
Source: Wikipedia

Filling in the Gaps in the Northern Sky (1687)

In 1641, Polish astronomer Johannes Hevelius built an observatory on the roofs of his three connected houses. Among the modern instruments was the largest telescope of its time, a 150 feet focal-length telescope.

Hevelius spent four years on this telescope, mapping the surface of the moon. His Selenographia, sive Lunae descriptio (Selenography, or A Description of The Moon) made him the the founder of Lunar topography.

Odly enough, Hevelius and his second wife Elisabeth did not use the telescope for their observations of the stars of the northern sky. They compiled data of no less than 1,564 stars - the largest number ever observed with the naked eye - in a star catalogue called Catalogus Stellarum Fixarum.

Johannes Hevelius died in 1687. The catalogue, together with an introduction and a star atlas called Firmamentum Sobiescianum were published by Elisabeth Hevelius in 1690.

The catalogue and the atlas contained ten new constellations, seven of which are still used today. These are: Canes Venatici (Hunting Dogs), Lacerta (Lizard), Leo Minor (Little Lion), Lynx (Lynx), Scutum (Shield), Sextans (Sextant), and Vulpecula (Fox).

The constellation Sextant was named after the instrument Hevelius and his wife used for the observations. Hevelius' observations were the last star catalogue that was compiled with the naked eye.

Sources: Wikipedia, Wikipedia, Ian Ridpath

Hevelius' telescope
Source: Wikipedia

Hevelius and his wife observing the sky with a brass sextant
Source: Wikipedia

Flamsteed's Catalogue (1725)

In 1675, English astronomer John Flamsteed was appointed the first Astronomer Royal. In this position, he assembled the first major star catalogue that was made with the aid of a telescope. It contained over 3,000 stars, doubling the number of stars observed by Hevelius. The Catalogue, called Catalogus Britannicus was published posthumously in 1725.

One of the "stars" in Flamsteed's Catalogue was the planet Uranus. However, it was not identified as planet until 1781, when William Herschel observed it.

While Flamsteed didn't receive credit for the planet he discovered, his name was immortalized for something he didn't invent: the Flamsteed Numbers, which identify individual stars in a constellation.

Sources: Wikipedia, Ian Ridpath

Flamsteed's Catalogue
Source: Wikipedia

The Astronomical Aberration of Light (1729)

By now, the Copernican heliocentric theory of the Solar System had received confirmation by the observations of Galileo and Tycho Brahe and the mathematical investigations of Kepler and Newton. In 1573, Thomas Digges had suggested that - according to the heliocentric model - parallactic shifting of the stars should occur.

In 1725, British astronomers James Bradley and Samuel Molyneux started researching the idea of stellar parallaxes. They found, that the the apparent motion of stars was caused neither by parallax nor by observational errors.

In 1727, Bradley developed a theory, that the apparent motion of celestial objects about their true positions dependend on the velocity of the observer. He presented the phenomenon, called astronomical aberration or stellar aberration to the Royal Society in 1729.

Source: Wikipedia

Gegenschein (1730)

Gegenschein (German for counterglow) is an optical phenomenon at the antisolar point in the night sky. It is caused by the backscatter of sunlight by interplanetary dust.

The first one to describe it was French astronomer Esprit Pézenas in 1730.

Between 1799 and 1803, it was observed by German explorer Alexander von Humboldt who gave the phenomenon its German name.

The most detailed explanation was given by Danish astronomer Theodor Brorsen in 1854.

Gegenschein above ESA's VLT
in the Atacama Desert
source: Wikipedia

Astronomical Nutation (1748)

After British astronomers James Bradley had figured out the Astronomical Aberration, there were were still some residual discrepancies in the stars' positions that could not be explained by aberration. Bradley suspected that they were caused by nutation taking place over the 18.6 year period of the revolution of the nodes of the Moon's orbit. (A lunar node is a point at which the orbit of the Moon intersects the ecliptic.

Yearly changes in the location of the Tropic of Cancer near a highway in Mexico; Wikipedia
To prove his idea, Bradley observed the complete cycle of revolution of the Lunar nodes over 20 years. During that time, in 1742, he was appointed Astronomer Royal (the third one after Flamsteed and Halley). Bradley presented his findings in 1748.

An important effect of Nutation is a change in the axial tilt of Earth with respect to the ecliptic plane, shifting the major circles of latitude (the tropical circles and the polar circles), that are defined by the Earth's tilt.

Source: Wikipedia

A New Hypothesis of the Universe (1750)

English astronomer Thomas Wright was the first to accurately describe the shape of the Milky Way In his book An original theory or new hypothesis of the Universe, he describes the Milky Way as "an optical effect due to our immersion in what locally approximates to a flat layer of stars."

He was also was one of the first astronomers to speculate that faint nebulae were actually distant galaxies.

Sources: Wikipedia, Milestone Books

Universal Natural History and Theory of the Heavens (1755)

The idea of distant galaxies was taken up again five years later by German philosopher Immanuel Kant, who in his opus Allgemeine Naturgeschichte und Theorie des Himmels, reasoned that the Solar System is merely a smaller version of the fixed star systems, such as the Milky Way and other galaxies, which he called Island Universes.

Kant noted that French philosopher Louis Maupertuis had discussed the idea that nebula-like objects (including the " Andromeda Nebula") were actually collections of stars as early as 1745.

Kant also picked up another idea, the Nebular Hypothesis first voiced by Swedish philosopher Emanuel Swedenborg in 1734, suggesting that the Solar System formed from gas and dust orbiting the Sun.

Sources: Wikipedia

Wright's "Original Theory"
Source: Wikimedia

Immanuel Kant's "Naturgeschichte"
Source: Wikipedia

Filling in the Gaps in the Southern Sky (1750 - 1763)

In 1750, French astronomer Nicolas-Louis de Lacaille set up a small observatory at the southern tip of Africa, the Cape of Good Hope. Here, within four years, he observed 9,766 stars.

Lacaille returned to France in 1754. His catalogue, called Coelum Australe Stelliferum (Stars of the Southern Sky) was published in 1763. It contained fourteen new constellations. One of them was named after the Table Mount where de Lacaille conducted his observations. The other thirteen symbolized the Age of Enlightenment. They were named after scientific instruments and artist's tools, including some unfamiliar ones like Fornax Chemica (the Chemical Oven) or Antlia Pneumatica (the Pneumatic Pump).

de Lacaille's Catalogue
Source: Wikimedia

Lacaille's fourteen constellations were: Antlia (Air Pump), Caelum (Chisel), Circinus (Draftsman's Compass), Fornax (Furnace), Horologium (Pendulum Clock), Mensa (Table Mount), Microscopium (Microscope), Norma (Set Square), Octans (Octant), Pictor (Easel), Pyxis (Mariner's Compass), Reticulum (Crosshairs Net), Sculptor (Sculptor), and Telescopium (Telescope),

Lacaille also divided Ptolemy's large constellation Argo Navis (The Ship) into Carina (Keel), Puppis (Poop Deck) and Vela (Sails). That division was made official in 1928.

In 1757, while still working on the Southern Sky, Lacaille published Astronomiae Fundamenta Novissimus (New Foundations of Astronomy).

It contained about 400 bright stars with positions for the first time corrected for aberration and nutation.

Sources: Wikipedia, Ian Ridpath, University of St. Andrews,

The Return of Halley's Comet (1758)

English astronomer Edmond Halley studied records of comets sighted in 1531, 1607, and 1682. After talking with Isaac Newton about his ideas of the laws of motion, Halley came to the conclusion that these records concerned the same comet.

He first presented his findings in 1696 and then again 1705, when he wrote the Synopsis of the Astronomy of Comets and predicted the return of the comet in 1758.

Halley didn't live to see his prediction come true. The reappearance - as predicted - in 1758 was first observed by German farmer and amateur astronom Georg Palitzsch. It provided a huge boost to Newton and Kepler's rules for celestial motions.

The name "Halley's Comet" was given to the comet by Louis de Lacaille.

Today we know, that the comet that now bears Halley's name has been recorded as early as 240 BC in China and 164 BC in Babylon.

Sources: Wikipedia

Halley's Synopsis

Uranus (1781)

In March 1781, during a search for double stars, German-born British astronomer William Herschel noticed an object appearing as a disk. Herschel originally thought it was a comet or a stellar disc, but - based on Herschel's observations - Russian Academician Anders Lexell computed the orbit and found it to be probably planetary.

Source: Wikipedia

With larger and larger telescopes, the time from the late 18th to the mid 20th Century was mainly a time of catalogs, maps and standards.

In addition, new breakthroughs in physics, most notably the the Theory of Relativity and the Theory of Quantum Mechanics provided a better understanding of the complex dynamics of the universe.

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