Former constellations are historical groupings of stars that were once proposed or depicted on celestial maps by astronomers but are no longer officially recognized as part of the 88 modern constellations standardized by the International Astronomical Union (IAU) in 1922. These patterns emerged largely between the 16th and 19th centuries, when European explorers and cartographers charted previously unknown southern skies and filled perceived gaps in the traditional Ptolemaic catalog of 48 ancient constellations.^[1] Many were invented to honor patrons, commemorate events, or reflect cultural or scientific interests of the time, such as animals, instruments, or mythological figures not included in earlier systems.^[2] The proliferation of former constellations reflected the lack of standardization in astronomy before the 20th century, with over 100 distinct patterns appearing on various star atlases by the 1800s.^[3] Pioneering astronomers like Petrus Plancius introduced southern constellations in the late 1500s based on sailors' observations, while Johannes Hevelius added 12 new ones in his 1690 atlas Firmamentum Sobiescianum, including figures like Scutum Sobiescianum (now simply Scutum).^[4] Later, Johann Elert Bode's 1801 Uranographia incorporated even more, such as Felis the Cat and the Printing Press (Officina Typographica), often overlapping existing areas or using faint stars.^[5] The IAU's 1922 decision, formalized with boundaries in 1930, rejected these to establish a single, non-overlapping division of the celestial sphere for scientific consistency.^[3] Among the most notable former constellations is Argo Navis, the Ship of the Argonauts from ancient Greek lore, which was too large and was subdivided by Nicolas-Louis de Lacaille in 1763 into the modern Carina (Keel), Puppis (Stern), and Vela (Sails).^[6] Others include Antinous, the deified youth who was the favorite of Roman Emperor Hadrian, first depicted on a celestial globe by Caspar Vopel in 1536;^[7] Quadrans Muralis, the Mural Quadrant representing an astronomical instrument, added by Jerome Lalande in 1795; and Apis, the Bee, introduced by Petrus Plancius in 1612.^[5] These and approximately 50 others, such as Cerberus the Hound of Hades and Custos Messium the Harvest Keeper, survive in historical texts and maps but hold no official status today, serving as reminders of astronomy's evolving nomenclature.^[2]

Definition and Historical Context

Defining Former Constellations

Former constellations refer to historical patterns of stars that were once formally proposed or recognized within astronomical catalogues and maps but were ultimately excluded from the modern standard of 88 official constellations, which the International Astronomical Union (IAU) established in 1922 to cover the entire celestial sphere without overlap.^[8] These exclusions occurred as part of the IAU's efforts to standardize celestial nomenclature amid increasing astronomical observations, with precise boundaries for the 88 constellations finalized and published in 1930 by Eugène Delporte in Délimitation Scientifique des Constellations.^[8] By the 19th century, historical star charts had accumulated over 100 such patterns, many of which were discarded to create a unified system.^[8] A key criterion for qualifying as a former constellation is that it must have been visually depicted on celestial globes or in printed star atlases, complete with assigned stars forming its outline, rather than existing solely as undocumented mythical or literary descriptions without astronomical representation.^[9] This requirement ensures the pattern was treated as a systematic astronomical entity in its time, often integrated into broader catalogues of stellar positions. In contrast, informal folk asterisms—such as the Big Dipper, a prominent star pattern within the official constellation Ursa Major—do not qualify, as they lack formal historical recognition as independent constellations and are instead recognized by the IAU as unofficial groupings distinct from bounded celestial regions.^[3] The historical scope of former constellations centers on the Western and European astronomical traditions, tracing back to the 48 constellations cataloged by Claudius Ptolemy in his Almagest around 150 CE, which provided a foundational framework of star groupings derived from earlier Greek and Babylonian influences.^[10] These Ptolemaic patterns evolved through Renaissance and Enlightenment-era additions, reflecting a continuous lineage of mapped stellar figures in European scholarship. Non-Western cultures, including Chinese and Indigenous traditions, developed parallel systems of star patterns adapted to their own observational and cultural contexts, though these are not encompassed in the definition of former constellations here.^[8] The IAU's 1930 delimitation process briefly referenced in broader historical overviews further solidified the exclusion of these earlier proposals to prioritize scientific consistency.^[8]

Evolution of Constellation Recognition

The recognition of constellations originated in ancient times, with the Greek astronomer Claudius Ptolemy compiling a foundational catalog in his Almagest during the 2nd century AD, which enumerated 48 constellations primarily visible from the Northern Hemisphere.^[11] This list, derived from earlier Babylonian and Greek traditions, served as the baseline for Western astronomy, grouping stars into mythological figures and providing positional data for over 1,000 stars.^[12] Ptolemy's work emphasized patterns observable from the Mediterranean region, establishing a system that influenced celestial mapping for over a millennium. During the Renaissance in the 15th and 16th centuries, European scholars expanded this framework amid voyages of exploration and advancements in printing, incorporating southern sky observations and elevating minor asterisms to constellation status, resulting in approximately 50 recognized patterns by the early 1600s.^[13] Figures like Albrecht Dürer contributed through his 1515 woodcut star charts, which depicted both northern and southern hemispheres with enhanced accuracy and artistic detail, including emerging southern figures based on recent traveler reports.^[14] Key milestones followed, such as Johann Bayer's Uranometria in 1603, which introduced 12 new southern constellations like Triangulum Australe and Pavo, drawn from observations by explorers like Amerigo Vespucci, thereby extending coverage to the full celestial sphere.^[15] Later, John Flamsteed's Historia Coelestis Britannica (1729) cataloged stars across 55 constellations, incorporating telescopic observations and proposing refinements that reflected growing precision in stellar positions.^[16] The 20th century brought standardization to resolve inconsistencies, with the International Astronomical Union (IAU) at its 1922 General Assembly in Rome adopting a definitive list of 88 constellations to ensure complete, non-overlapping coverage of the sky without gaps or ambiguities.^[8] This decision excluded numerous historical proposals, formalized in Eugène Delporte's 1930 atlas Délimitation scientifique des constellations, which defined precise boundaries along lines of right ascension and declination for the first time.^[17] Many former constellations became obsolete due to overlaps with established patterns, limited visibility from major observatories, or redundancy in star groupings, as the IAU prioritized a unified system for astronomical research and navigation.^[18] For instance, expansive figures like Argo Navis were subdivided to eliminate redundancies, ensuring each sky region belonged to exactly one constellation.^[19]

Major Historical Proposals

17th and 18th Century Additions

The 17th and 18th centuries marked a significant expansion in proposed constellations, fueled by European Age of Exploration voyages that unveiled previously unobserved southern hemisphere stars, combined with the recent invention of the telescope around 1608, which allowed for more precise stellar mapping and differentiation of faint objects. Dutch navigators, sponsored by the Dutch East India Company, charted new skies during expeditions to the East Indies, providing astronomers with data on regions invisible from northern Europe. This era saw a proliferation of new asterisms as cartographers and scholars sought to systematize these discoveries, often drawing from exotic fauna, navigational tools, or cultural motifs to fill perceived gaps in the celestial sphere.^[20] Key figures driving these additions included Petrus Plancius, a Dutch theologian and cartographer, who in the 1590s devised 12 new southern constellations based on observations by navigator Pieter Dirkszoon Keyser during a 1595-1597 voyage to the Indies; notable among these was Columba Noachi, representing Noah's Dove from biblical lore. Building on this, German astronomer Johann Bayer incorporated 12 additional southern asterisms into his influential 1603 star atlas Uranometria, including Dorado (the dolphinfish) and Tucana (the toucan), adapting Plancius's work with refined positions. In the 18th century, French astronomer Nicolas-Louis de Lacaille laid groundwork through his 1751-1753 observations at the Cape of Good Hope, proposing early southern figures like Norma (the level) and Circinus (the compass), which emphasized scientific precision over mythological themes.^[21][22] Notable 17th-century examples include Scutum Sobiescianum, introduced in 1684 by Polish astronomer Johannes Hevelius to honor King John III Sobieski's victory at the Battle of Vienna, depicting a shield with a cross; this was part of Hevelius's broader additions in his Firmamentum Sobiescianum atlas. By the 18th century, proposals continued with Lacaille's instrumental-themed asterisms, such as those honoring drafting tools, reflecting the Enlightenment's focus on empirical science. Overall, this period generated dozens of such proposals, with estimates ranging from 30 to 40 new figures across various atlases.^[23][22] Motivations for these additions varied, often blending scientific advancement with personal or nationalistic commemoration: Plancius and Bayer honored explorers and exotic discoveries to aid navigation, while Hevelius commemorated political heroes, and Lacaille celebrated Enlightenment-era instruments to promote rational inquiry. Biblical or allegorical elements, like Plancius's Columba Noachi, also appealed to contemporary religious sentiments.^[20][21][23] Many of these 17th- and 18th-century additions met mixed fates, with some absorbed into larger official patterns—such as parts of Argo Navis later divided—or outright rejected by later astronomers due to their faint stars and limited visibility from northern latitudes, where most observatories were located; by the 19th century, only a subset endured in standardized catalogs.^[22]

19th Century Innovations

The 19th century marked the final phase of constellation innovation in Western astronomy, driven by advancements in star cataloguing from major observatories such as the Paris Observatory and the emergence of amateur astronomy through accessible tools like celestial globes and popular atlases. Improved precision in positional data, exemplified by Jérôme Lalande's comprehensive catalogue of nearly 48,000 stars compiled between 1791 and 1801, encouraged astronomers to fill perceived gaps in the celestial sphere with new figures, often reflecting contemporary scientific, cultural, or national interests.^[24] This period saw a proliferation of proposals amid growing competition, as cartographers like Johann Elert Bode and Alexander Jamieson produced elaborate star atlases to rival French counterparts, resulting in an estimated 20 to 30 additional constellation suggestions that overlapped with existing patterns.^[25] Key figures in these innovations included Jérôme Lalande, whose late-18th-century ideas extended influential into the early 19th through Bode's 1801 Uranographia, where he proposed whimsical and thematic figures such as Felis (the Cat) in 1799—created out of his personal fondness for felines—and Globus Aerostaticus (the Hot Air Balloon) around 1798, honoring the French Montgolfier brothers' invention.^[26] Alexander Jamieson, a Scottish educator, introduced three new constellations in his 1822 Celestial Atlas: Noctua (the Owl), a replacement for the obscure Solitaire in the southern skies; Solarium (the Sundial), supplanting Lacaille's Reticulum to emphasize timekeeping instruments; and Norma Nilotica (the Nilometer), a rod for measuring Nile flood levels held by Aquarius, blending ancient Egyptian lore with practical hydrology.^[27] Johann Elert Bode, in revisions to his earlier works culminating in the expansive 1801 atlas, incorporated and promoted several of these, including Lalande's Quadrans Muralis (the Mural Quadrant) from 1795, which depicted a scientific instrument for measuring star positions, alongside his own additions like Officina Typographica (the Printing Press) to celebrate Gutenberg's invention.^[28][29] These proposals often veered into absurdity and redundancy, featuring scientific tools (e.g., quadrants and sundials), historical figures, or everyday animals like the hen in Gallina (popularized in 19th-century globes despite its 1612 origins by Petrus Apianus), as astronomers competed to personalize the skies amid nationalistic fervor—French-themed designs like Lalande's balloon contrasted with Bode's German printing press.^[24] Increasing overlap, such as Jamieson's Noctua encroaching on established birds like Aquila, highlighted the clutter, with proposals sometimes satirical or self-promotional, like John Hill's earlier but lingering 18th-century menagerie influencing 19th-century whimsy.^[1] By the mid-19th century, this proliferation caused confusion in navigation and scientific communication, prompting calls for standardization from bodies like the Astronomische Gesellschaft, which emphasized consistent boundaries over inventive figures. The era's innovations, while creative, ultimately underscored the need for reform, leading to the International Astronomical Union's 1922 delimitation that excluded most former constellations.

Prominent Former Constellations

Argo Navis

Argo Navis originated in the Ptolemaic era as one of the 48 ancient constellations cataloged by the Greco-Roman astronomer Claudius Ptolemy in his Almagest around 150 CE, depicting the mythical ship sailed by Jason and the Argonauts in their quest for the Golden Fleece.^[30] This vast pattern represented a penteconter, a 50-oared galley, and was positioned entirely in the southern celestial hemisphere, visible from locations like Alexandria but not from much of northern Europe.^[31] Spanning approximately 64 degrees in declination and covering approximately 1,667 square degrees—about 4% of the visible sky and 28% larger than the modern constellation Hydra—it dominated much of the southern skies, extending from near the equator southward into the Milky Way.^[31] The constellation's key features included prominent stars such as Canopus (Alpha Carinae), the second-brightest star in the night sky at magnitude -0.74, which Ptolemy assigned as the ship's helmsman and which later became the alpha star of Carina.^[30] Other notable components were bright stars like Miaplacidus (Beta Carinae) and Suhail (Lambda Velorum), forming the ship's outline. In historical star atlases, Argo Navis was elaborately illustrated as a fully rigged vessel, often shown stern-first with sails, oars, and deck details emerging from the Milky Way, varying from ancient Greek galley forms to later European galleon interpretations by cartographers like Johann Bayer in his 1603 Uranometria.^[30] Due to its immense size, which complicated astronomical cataloging and mapping, Argo Navis was subdivided in the mid-19th century, with British astronomer Francis Baily proposing the division in his 1845 British Association Catalogue to better manage its 45 Ptolemaic stars, followed by American astronomer Benjamin Apthorp Gould's adoption and refinement in his 1879 Uranometria Argentina, which assigned Greek letters sequentially across the parts.^[32] This resulted in three separate constellations: Carina (the keel), Puppis (the stern), and Vela (the sails), building on earlier suggestions by Nicolas-Louis de Lacaille in 1756.^[30] The International Astronomical Union (IAU) formalized this obsolescence in 1922 during its establishment of the modern 88-constellation system, permanently excluding Argo Navis as a unified pattern and retaining only its subdivided components, with no single ship outline preserved in official boundaries.^[30] Culturally, Argo Navis was deeply tied to Greek mythology, symbolizing the epic voyage of Jason and the Argonauts, blessed by Athena and carried to the heavens by the gods after their success, as recounted in Apollonius Rhodius's Argonautica.^[31] Its stars, particularly Canopus, played a significant role in southern hemisphere navigation, serving as a key guide for ancient mariners, Polynesian voyagers, and later European explorers crossing the Indian and Pacific Oceans, where it marked southeasterly directions in star compasses like the Hawaiian nā ʻaoʻao.^[33]

Quadrans Muralis

Quadrans Muralis, meaning "mural quadrant" in Latin, was proposed in 1795 by the French astronomer Joseph Jérôme Lefrançois de Lalande to honor the mural quadrant, a wall-mounted astronomical instrument used for precise angular measurements.^[28] This constellation occupied a region of faint stars positioned between the constellations Boötes and Draco, near the northern celestial pole and adjacent to the tail of Ursa Major.^[34] Lalande's creation reflected the era's growing emphasis on scientific instruments in celestial nomenclature, as part of broader 18th-century trends toward modernizing star patterns.^[28] The constellation's key features included a pattern of dim stars, mostly below fourth magnitude, forming a quarter-circle shape reminiscent of the instrument's arc, complete with a plumb line and sight.^[35] It first appeared in printed form as Le Mural in the 1795 edition of Jean-Baptiste Fortin's Atlas Céleste, edited by Lalande himself, where it was illustrated as a detailed engraving of the quadrant against a starry backdrop.^[36] Over the following decades, Quadrans Muralis gained modest recognition; for instance, Friedrich Wilhelm August Argelander cataloged 37 stars within its boundaries in his 1843 observations, and it persisted in some European star atlases into the late 19th century. This usage spanned approximately a century, from its introduction until the early 20th century, during which it served as a reference for northern sky mapping among astronomers familiar with Lalande's work.^[28] Quadrans Muralis fell into obsolescence with the International Astronomical Union's 1922 delimitation of the 88 modern constellations, where it was excluded due to its lack of prominent stars and significant overlap with the established figure of Coma Berenices, to which many of its stars were reassigned.^[34] The decision streamlined celestial boundaries, prioritizing ancient and widely recognized patterns over newer, less distinctive proposals.^[28] Despite its short-lived status, Quadrans Muralis holds historical significance as an emblem of the transition in the late 18th and 19th centuries toward constellations inspired by scientific tools, foreshadowing the standardization that would soon follow under international agreement. Its legacy endures indirectly through the Quadrantids meteor shower, whose radiant lies in the former area and retains the name in astronomical nomenclature.^[34]

Other Significant Examples

Scutum Sobiescianum was introduced in 1684 by the Polish astronomer Johannes Hevelius to commemorate King John III Sobieski's victory over the Ottoman forces at the Battle of Vienna in 1683.^[23] This small constellation depicted a shield adorned with a cross, formed by seven faint stars of fourth and fifth magnitude located near Aquila in the summer sky.^[23] Although the full name Scutum Sobiescianum fell out of use, the figure was retained in modern astronomy as Scutum, the Shield, becoming one of the 88 official constellations defined by the International Astronomical Union in 1922.^[37] Lilium, or the Lily, represented a floral emblem inspired by the fleur-de-lis symbol of French royalty and was proposed in 1679 by the French astronomer Augustin Royer in his celestial atlas.^[19] Positioned in the northern sky within the boundaries of Aries using four stars previously known as Apes (the Bee) from Johann Bayer's 1603 Uranometria, it aimed to add a decorative element but was soon deemed redundant amid overlapping proposals.^[38] The constellation appeared briefly in some 17th- and 18th-century charts before being absorbed into larger figures like Hevelius's Musca Borealis (the Northern Fly) in 1690, ultimately disappearing from standard catalogs due to its lack of distinct stellar pattern.^[38] Gallus, the Rooster, was created in 1612 by the Dutch cartographer Petrus Plancius on his celestial globe, drawing from an avian theme to fill gaps in the southern Milky Way.^[39] This faint constellation occupied stars now part of Puppis, near the stern of the ancient ship Argo Navis, but its placement proved awkward and overlapping, leading later astronomers like Hevelius to reassign the stars back to Argo.^[39] Excluded from official recognition during the 1922 International Astronomical Union delimitation, Gallus survived only in early globes and maps, exemplifying how thematic but poorly integrated figures faded from use.^[39] These examples illustrate broader patterns among former constellations, often motivated by commemorative tributes to historical figures or decorative additions like floral and animal motifs to embellish sparse sky regions.^[19] Many such proposals enjoyed short-lived inclusion on 18th-century celestial globes, including Johann Gabriel Doppelmayr's 1742 Atlas Coelestis, which incorporated obsolete figures alongside contemporary ones to showcase evolving astronomical representations.^[40]

Comprehensive Catalogues

List by Proposer

The former constellations are organized below alphabetically by the primary proposer, drawing from historical star atlases and catalogues such as those documented in Ian Ridpath's Star Tales and contemporary analyses of obsolete figures.^[1] Each entry notes the year proposed, approximate location in the sky, and a brief reason for the proposal. Johann Elert Bode

• Honores Frederici: Proposed in 1787, located near Andromeda, this constellation depicted five stars as laurels honoring Prussian king Frederick the Great's military and cultural achievements.^[9]
• Machina Electrica: Proposed in 1800, situated near Sculptor and Fornax, it represented an early electrical generator to symbolize contemporary scientific progress in electricity.^[1]
• Officina Typographica: Proposed in 1801, placed near Puppis and Canis Major, this figure illustrated a printing press to commemorate the invention of movable type and its impact on knowledge dissemination.^[1]

Edmond Halley

• Malus: Proposed in 1679, near the south celestial pole, this mast or apple tree was created to catalog stars from Halley's St. Helena expedition.^[1]

Johannes Hevelius

• Cerberus: Proposed in 1690, located near Hercules and Draco, the three-headed dog from Greek mythology was added to fill northern sky voids and evoke classical lore.^[19]
• Mons Maenalus: Proposed in 1690, situated near Boötes, the mountain from Arcadia in Greek myth was depicted to organize faint stars in that region.^[19]
• Ramus Pomifer: Proposed in 1690, placed near Cassiopeia, the apple-bearing branch alluded to the Hesperides myth to fill sparse areas with mythological elements.^[19]
• Tangentia: Proposed in 1690, located near Scutum, this geometric tangent line was introduced to represent mathematical concepts in astronomy.^[1]

John Hill

• Aranea: Proposed in 1754, near Virgo, the spider was part of a natural history series to classify stars with zoological figures from British fauna.^[1]
• Bufo: Proposed in 1754, situated near Capricornus, the toad figure aimed to map the sky using everyday animal forms for educational purposes.^[19]
• Hirudo: Proposed in 1754, near Aquarius, the leech was included to promote natural history themes in celestial cartography.^[1]
• Limax: Proposed in 1754, placed near Sagittarius, the slug represented terrestrial invertebrates to fill gaps with relatable natural motifs.^[1]
• Lumbricus: Proposed in 1754, near Libra, the earthworm was proposed to integrate biological diversity into astronomical illustrations.^[19]
• Noctua: Proposed in 1754, near Pegasus, the owl symbolized wisdom and night to organize stars in a whimsical manner.^[1]
• Rangifer: Proposed in 1754, near Perseus, the reindeer drew from northern wildlife to appeal to British audiences.^[1]
• Sirena: Proposed in 1754, near Eridanus, the siren from mythology was added for artistic and narrative appeal in sky mapping.^[19]
• Testudo: Proposed in 1754, near Pisces, the tortoise highlighted reptilian life to create a comprehensive natural-themed atlas.^[1]
• Trochilus: Proposed in 1754, near Hydra, the hummingbird (or crocodile bird) was chosen for its exotic appeal in global natural history.^[1]

Jérôme Lalande

• Felis: Proposed in 1799, located near Hydra and Antlia, the cat was introduced to fill space with a domestic animal figure for relatable sky patterns.^[19]
• Quadrans Muralis: Proposed in 1795, situated between Boötes and Draco, the mural quadrant honored the astronomical instrument used for meridian observations.^[9]

Petrus Plancius

• Apis: Proposed in 1612, near Centaurus in the southern sky, the bee was created from voyage observations to represent exotic southern fauna.^[41]
• Cancer Minor: Proposed in 1612, near Cancer Major, the lesser crab filled northern gaps inspired by zodiac extensions.^[42]
• Jynx: Proposed in 1612, near Orion, the wryneck bird was added as a biblical or exotic avian figure from Dutch explorations.^[21]
• Musca Borealis: Proposed in 1612, in Aries, the northern fly organized faint stars with an insect motif complementary to southern creations.^[19]
• Gallus: Proposed in 1612, near Puppis, the rooster figure was introduced to fill gaps in the celestial map based on observations during southern voyages.^[9]

Julius Schiller

• Apis Hebraica: Proposed in 1627, near Scorpio, the Hebrew bee reimagined zodiac signs with biblical themes to Christianize the celestial sphere.^[1]
• Fortuna: Proposed in 1627, near Leo, the fortune figure replaced pagan zodiac elements with allegorical Christian virtues.^[1]
• Rex: Proposed in 1627, near Aries, the king represented Christ or apostles to overlay religious iconography on ancient patterns.^[1]

Alexander Jamieson

• Camulus: Proposed in 1822, near Perseus, the ancient British god figure honored Celtic mythology in a late attempt to expand northern constellations.^[1]
• Tortoise: Proposed in 1822, near Cetus, this was a revised natural history entry to evoke endurance in celestial mapping.^[19]

This compilation references approximately 50 documented former constellations, with fuller catalogues available in historical works like Hevelius's Firmamentum Sobiescianum (1690) and Bode's Uranographia (1801), as analyzed in modern astronomical histories. For a complete list, see resources like Ian Ridpath's Star Tales.^[1]

Chronological Overview

The recognition and proposal of constellations evolved sporadically from antiquity through the early 20th century, but former constellations—those no longer officially recognized—largely emerged in waves during the 17th to 19th centuries as astronomers mapped faint stars and sought to honor patrons or fill gaps in the celestial sphere. These proposals peaked amid European exploration of southern skies and advancements in cartography, before the International Astronomical Union (IAU) standardized 88 constellations in 1922, effectively freezing further additions and rendering most prior innovations obsolete.^[19]

2nd Century and Earlier

• Argo Navis (proposer: Claudius Ptolemy, southern sky region, partially retained as Carina, Puppis, and Vela after division by Nicolas-Louis de Lacaille in the 18th century).^[19]
• Antinous (proposer: Emperor Hadrian, Aquila region, fully obsolete).^[19]
• Capra and Haedi (proposer: Aratus, Auriga region, fully obsolete asterisms).^[19]
• Phaethon (proposer: Aratus/Hyginus, Eridanus region, fully obsolete).^[19]
• Piscis Notius (proposer: Aratus, southern sky region, fully obsolete).^[19]

1500s

Around a dozen proposals appeared in this century, driven by early modern explorers and cartographers introducing southern patterns, though many remained marginal.

• Triangulus Antarcticus (proposer: Petrus Plancius, southern sky near Triangulum Australe, fully obsolete).^[19]
• Rosa (proposer: Petrus Apianus, Coma Berenices region, fully obsolete).^[19]
• Deltoton (proposer: Petrus Apianus, southern sky, fully obsolete).^[19]
• Polophylax (proposer: Petrus Plancius, near Hydrus, Phoenix, and Tucana, fully obsolete).^[19]
• Apis (proposer: Petrus Plancius, Hydra region, fully obsolete; see Major Historical Proposals for Plancius' contributions).^[19]
• Linum Piscium (proposer: Thomas Hood, near Pisces, fully obsolete).^[19]
• Urna (proposer: Zacharias Bornmann, northern sky, fully obsolete).^[19]

1600s

This century saw a surge of about 25 additions, including Johann Bayer's 1603 popularization of 12 southern patterns (many later retained, but sparking obsolete offshoots) and Johannes Hevelius' 1690 set of 12, reflecting enthusiasm for filling voids in northern and southern charts.

• Apes (proposer: Petrus Plancius, Aries region, fully obsolete).^[19]
• Musca Borealis (proposer: Petrus Plancius, near Musca, fully obsolete).^[19]
• Jordanus (proposer: Petrus Plancius, Leo, Leo Minor, and Lynx regions, fully obsolete).^[19]
• Cancer Minor (proposer: Petrus Plancius, Gemini region, fully obsolete).^[19]
• Gallus (proposer: Petrus Plancius, Canis Major region, fully obsolete).^[19]
• Sagitta Australis (proposer: Petrus Plancius, Scorpius region, fully obsolete).^[19]
• Tigris (proposer: Petrus Plancius, Pegasus and Ophiuchus regions, fully obsolete).^[19]
• Vespa (proposer: Jakob Bartsch, Aries region, fully obsolete).^[19]
• Sudarium Veronicae (proposer: Antoine Marie Schyrle de Rheita, Leo and Sextans regions, fully obsolete).^[19]
• Lilium (proposer: Augustin Royer, Aries region, fully obsolete).^[19]
• Sceptrum et Manus Iustitiae (proposer: Augustin Royer, Andromeda region, fully obsolete).^[19]
• Robur Carolinum (proposer: Edmund Halley, near Crux, partially retained as star names but constellation obsolete).^[19]
• Cor Caroli Regis Martyris (proposer: Charles Scarborough, Canes Venatici region, partially retained as star name Alpha Canum Venaticorum but constellation obsolete).^[19]
• Gladii Electorales Saxonici (proposer: Gottfried Kirch, northern sky, fully obsolete).^[19]
• Pomum Imperiale (proposer: Gottfried Kirch, northern sky, fully obsolete).^[19]
• Sceptrum Brandenburgicum (proposer: Gottfried Kirch, northern sky, fully obsolete).^[19]
• Cerberus (proposer: Johannes Hevelius, Hercules region, fully obsolete; part of Hevelius' 1690 surge).^[19]
• Mons Maenalus (proposer: Johannes Hevelius, Boötes region, fully obsolete).^[19]
• Ramus Pomifer (proposer: Johannes Hevelius, near Coma Berenices, fully obsolete).^[19]
• Sextans Uraniae (proposer: Johannes Hevelius, Hydra region, fully obsolete).^[19]
• Triangulum Majus (proposer: Johannes Hevelius, northern sky, fully obsolete).^[19]
• Triangulum Minus (proposer: Johannes Hevelius, northern sky, fully obsolete).^[19]
• Asterion and Chara (proposer: Johannes Hevelius, Canes Venatici region, fully obsolete).^[19]
• Phoenicopterus (proposer: Petrus Plancius and Paul Merula, southern sky, fully obsolete).^[19]
• Siren, Ceneus, and Lang (proposer: unknown/Willem Jansz Blaeu, near Triangulum Australe and Musca, fully obsolete).^[19]

1700s

The 18th century marked the peak with over 50 proposals, including John Hill's 1754 set of 15 zoological figures and Jérôme Lalande's 1795 Quadrans Muralis, often as tributes or scientific novelties amid Enlightenment mapping efforts.

• Corona Firmiana (proposer: Corbinianus Thomas, northern sky, fully obsolete).^[19]
• Tarandus or Rangifer (proposer: Pierre Charles Le Monnier, near Cepheus, fully obsolete).^[19]
• Anguilla (proposer: John Hill, near Aquarius, fully obsolete; part of Hill's 1754 zoological series).^[19]
• Aranea (proposer: John Hill, near Virgo, fully obsolete).^[19]
• Bufo (proposer: John Hill, near Aquarius, fully obsolete).^[19]
• Dentalium (proposer: John Hill, near Cetus, fully obsolete).^[19]
• Gryphites (proposer: John Hill, near Pegasus, fully obsolete).^[19]
• Hippocampus (proposer: John Hill, near Capricornus, fully obsolete).^[19]
• Hirudo (proposer: John Hill, near Eridanus, fully obsolete).^[19]
• Limax (proposer: John Hill, near Sculptor, fully obsolete).^[19]
• Lumbricus (proposer: John Hill, near Eridanus, fully obsolete).^[19]
• Manis (proposer: John Hill, near Cetus, fully obsolete).^[19]
• Patella (proposer: John Hill, near Cetus, fully obsolete).^[19]
• Pinna Marina (proposer: John Hill, near Cetus, fully obsolete).^[19]
• Scarabeus (proposer: John Hill, near Scorpius, fully obsolete).^[19]
• Testudo (proposer: John Hill, near Cetus, fully obsolete).^[19]
• Uranoscopus (proposer: John Hill, near Cetus, fully obsolete).^[19]
• Custos Messium (proposer: Jérôme Lalande, Virgo region, fully obsolete).^[19]
• Psalterium Georgii (proposer: Maximilian Hell, near Lyra, fully obsolete).^[19]
• Telescopium Herschelii (proposer: Maximilian Hell, southern sky, fully obsolete).^[19]
• Tubus Herschelii Major (proposer: Maximilian Hell, southern sky, fully obsolete).^[19]
• Tubus Herschelii Minor (proposer: Maximilian Hell, southern sky, fully obsolete).^[19]
• Taurus Poniatovii (proposer: Marcin Poczobut, Taurus region, fully obsolete).^[19]
• Leo Palatinus (proposer: Karl-Joseph König, Leo region, fully obsolete).^[19]
• Frederici Honores (proposer: Johann Elert Bode, northern sky, fully obsolete; see Major Historical Proposals for Bode's innovations).^[19]
• Turdus Solitarius (proposer: Pierre Charles Le Monnier, near Hydrus, fully obsolete).^[19]
• Quadrans Muralis (proposer: Jérôme Lalande, northern sky near Boötes, fully obsolete; see Prominent Former Constellations for details).^[19]
• Globus Aerostaticus (proposer: Jérôme Lalande, near Aquarius, fully obsolete).^[19]
• Felis (proposer: Jérôme Lalande, near Hydra, fully obsolete).^[19]
• Quadratum (proposer: Carel Allard, southern sky, fully obsolete).^[19]
• Machina Electrica (proposer: Johann Elert Bode, near Sculptor, fully obsolete).^[19]
• Lochium Funis (proposer: Johann Elert Bode, near Fornax, fully obsolete).^[19]
• Officina Typographica (proposer: Johann Elert Bode, near Puppis, fully obsolete).^[19]

1800s

Approximately 25 innovations occurred, including Alexander Jamieson's 1822 set of 11 and scattered tributes, but adoption waned as standardization loomed.

• Battery of Volta (proposer: Thomas Young, near Sculptor, fully obsolete).^[19]
• Marmor Sculptile (proposer: William Crosswell, near Sculptor, fully obsolete).^[19]
• Sciurus Volans (proposer: William Crosswell, near Sculptor, fully obsolete).^[19]
• Noctua (proposer: Alexander Jamieson, near Apus, fully obsolete; part of Jamieson's 1822 series).^[19]
• Solarium (proposer: Alexander Jamieson, near Apus, fully obsolete).^[19]
• Malus (proposer: John Herschel, near Pyxis, fully obsolete).^[19]
• Pluteum (proposer: Richard Andree, near Eridanus, fully obsolete).^[19]
• Camulus (proposer: Alexander Jamieson, near Perseus, fully obsolete).^[19]
• Tortoise (proposer: Alexander Jamieson, near Cetus, fully obsolete).^[19]

Post-1900, no major proposals emerged, with the IAU's 1922 delimitation and Eugène Delporte's 1930 boundary definitions excluding all former constellations from official use, preserving only select names or patterns in nomenclature.^[19]

Legacy in Modern Astronomy

Retained Nomenclature and Patterns

Despite the standardization of the 88 modern constellations by the International Astronomical Union (IAU) in 1922, with boundaries formalized in 1930, elements of former constellations persist in contemporary astronomical nomenclature and visual patterns. Bayer and Flamsteed designations assigned to stars during the era of obsolete constellations were largely retained, ensuring continuity in cataloging. For instance, in the subdivided remnants of the ancient Argo Navis, stars now in Vela bear Greek-letter labels originally given to the larger ship figure, such as Gamma Velorum (γ Velorum), a prominent blue supergiant that was part of Argo's sail section. Similarly, designations in Carina and Puppis follow the original sequence from Argo, with Carina holding the alpha and beta stars (Canopus as α Carinae and Miaplacidus as β Carinae), while Vela and Puppis lack these to avoid duplication.^[43] Visual patterns from former constellations also endure in the modern sky. The division of Argo Navis into Carina (the keel), Puppis (the stern), and Vela (the sails) in 1763 by Nicolas-Louis de Lacaille preserved the ship's thematic structure, allowing observers to trace the original outline across these three adjacent constellations along the Milky Way. Scutum, introduced in 1690 by Johannes Hevelius as Scutum Sobiescianum and retained in the IAU list, maintains its distinctive shield shape as a compact diamond-like asterism of four main stars—Alpha, Beta, Delta, and Epsilon Scuti—evoking the heraldic emblem it represents.^[8][44] Specific asterisms further echo these historical figures. The False Cross, formed by Delta and Kappa Velorum alongside Epsilon and Iota Carinae, mimics a cruciform pattern reminiscent of Argo Navis's rigging and is often confused with the nearby Southern Cross (Crux); this grouping highlights how faint stellar alignments from the former ship constellation linger in southern skies. The IAU's 1930 boundary delineations, drawn by Eugène Delporte along lines of right ascension and declination for the epoch B1875.0, incorporated outlines from former constellations to prevent gaps and preserve traditional star groupings, such as allocating variable stars to their historical homes. The official IAU list of 88 constellations includes annotations on these mergers, noting how entities like Argo Navis were fragmented rather than discarded.^[45][8]

Influence on Current Boundaries

The establishment of the 88 modern constellations by the International Astronomical Union (IAU) in 1922, with boundaries formalized by Eugène Delporte and published in 1930, systematically addressed overlaps and gaps from historical proposals, including former constellations, to create a uniform celestial division. This process excluded numerous obsolete figures, such as those proposed by Petrus Plancius and others, while incorporating elements from retained historical designs to eliminate ambiguities in star assignments. For instance, shared stars that previously belonged to multiple constellations, like those on the fringes of Pegasus and Andromeda, were definitively assigned to single regions, ensuring no overlaps or unassigned areas remained. Delporte's boundaries, drawn along lines of constant right ascension and declination at the 1875.0 epoch, were approved at the IAU's 1928 General Assembly in Leiden, building on earlier southern hemisphere delineations by Benjamin Gould to resolve inconsistencies from pre-20th-century maps.^[18][46] Former constellations significantly influenced boundary decisions through mergers and absorptions, particularly in regions with dense historical proposals. The vast Ptolemaic constellation Argo Navis, one of the largest ancient figures, was subdivided in 1763 by Nicolas-Louis de Lacaille into Carina (the keel), Vela (the sails), and Puppis (the stern) to facilitate more manageable charting, a division that the IAU retained and integrated into its 1930 boundaries, thereby shaping the southern celestial framework. Similarly, smaller former entities like Cancer Minor, introduced by Plancius in 1612 using stars near the modern Cancer-Gemini border, were excluded, with their areas redistributed into adjacent official constellations to fill gaps without creating new names. In the northern sky, Johannes Hevelius's 17th-century additions, such as Lynx, were adopted outright, defining edges between Ursa Major, Auriga, Gemini, and Cancer by occupying previously undefined spaces and preventing extensions from neighboring figures. These adjustments ensured comprehensive coverage of the celestial sphere, with Delporte modifying Gould's southern lines to align with IAU standards.^[18][31][47] The navigational legacy of southern former constellations, exemplified by Argo Navis, persisted in the modern boundaries of Vela and Puppis, which mariners continued to use for orientation in the southern hemisphere long after the 1930 standardization. These divisions preserved key navigational stars like Canopus in Carina, aiding maritime travel by maintaining familiar patterns amid the Milky Way, even as the full Argo figure was obsolete. Scientifically, the precise IAU boundaries reduced confusion in astronomical catalogs by assigning every celestial object to a unique region, enabling accurate coordinate referencing for observations, variable star monitoring, and meteor tracking without prior ambiguities from ill-defined historical limits. Post-1922, this facilitated enhanced consistency in catalogs using equatorial coordinates, such as the General Catalogue of 1950.^[48][18] In contemporary contexts, elements of former constellations occasionally revive in educational tools and software simulations to illustrate historical astronomy. For example, programs like Stellarium allow users to overlay obsolete figures such as Argo Navis or Hevelius's designs on modern boundaries, aiding teaching of celestial evolution without altering official IAU delineations. This approach highlights how past proposals informed current edges, fostering understanding of boundary decisions in classrooms and virtual sky models.