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There are 88 officially recognized constellations. Together, these International Astronomical Union (IAU) regions cover the entire sky. The names and boundaries are standardized; the lines people draw between stars are optional visual guides, not the boundaries themselves.
This guide gives the complete Latin-name list, explains how the modern system was established, and shows how to use a chart for your own location and season. It also separates official constellation areas from asterisms such as the Big Dipper and Summer Triangle.
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What the 88 constellations actually are
An official constellation is a precisely defined area of the celestial sphere. Its edges follow coordinates, so astronomers can say that a star, galaxy or other object lies in a particular constellation even when it is nowhere near the familiar stick-figure outline.
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Constellations are also perspectives rather than physical star families. Stars that appear next to one another may be separated by enormous distances and have no gravitational relationship. Their apparent arrangement is caused by viewing them from Earth. The constellation is a useful map address, not a claim that its stars formed together or remain physically linked.
The word “in” has a precise meaning in professional use: an object is in a constellation when its celestial coordinates fall inside that constellation’s official border. It does not have to sit on one of the lines in a popular drawing. This distinction matters when reading catalogs, planning observations or reporting the position of a transient object.
How the official list was established
The IAU agreed on the modern set of 88 names at its first General Assembly in Rome in 1922. At the 1925 Cambridge General Assembly, Eugène Delporte presented a boundary system based on right ascension and declination. The IAU approved those boundaries at Leiden in 1928, and the results were published in 1930.
Delporte’s task included keeping known variable stars in the constellations to which they had already been assigned. That requirement helps explain why some borders look irregular instead of following neat geometric shapes. A border is not designed simply to make a pleasing animal, object or mythological figure; it is a historical and coordinate-based solution that preserves established assignments.
The IAU’s official chart material records each constellation’s Latin name, pronunciation guidance, three-letter abbreviation, English name, genitive (possessive) form, chart position and boundary coordinates. Boundary files use right ascension and declination in the J2000 coordinate system. The IAU also supplies charts designed for screen viewing and printing; its chart artwork is released under a Creative Commons Attribution 4.0 license, so attribution is required when reusing it.
The 1922 decision established the set of names, while the later work made the set operational as a complete division of the sky. Before that standardization, atlases could disagree about where one figure ended and another began. The IAU framework lets observers in different countries use the same region name for the same coordinates.
Complete list of all 88 IAU constellations
The list below uses the Latin names as the primary reference keys and follows alphabetical order. Boötes is often written “Bootes” when diacritical marks are unavailable. The IAU recognizes the Latin form Boötes.
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| No. | IAU constellation |
|---|---|
| 1 | Andromeda |
| 2 | Antlia |
| 3 | Apus |
| 4 | Aquarius |
| 5 | Aquila |
| 6 | Ara |
| 7 | Aries |
| 8 | Auriga |
| 9 | Boötes |
| 10 | Caelum |
| 11 | Camelopardalis |
| 12 | Cancer |
| 13 | Canes Venatici |
| 14 | Canis Major |
| 15 | Canis Minor |
| 16 | Capricornus |
| 17 | Carina |
| 18 | Cassiopeia |
| 19 | Centaurus |
| 20 | Cepheus |
| 21 | Cetus |
| 22 | Chamaeleon |
C–H
| No. | IAU constellation |
|---|---|
| 23 | Circinus |
| 24 | Columba |
| 25 | Coma Berenices |
| 26 | Corona Australis |
| 27 | Corona Borealis |
| 28 | Corvus |
| 29 | Crater |
| 30 | Crux |
| 31 | Cygnus |
| 32 | Delphinus |
| 33 | Dorado |
| 34 | Draco |
| 35 | Equuleus |
| 36 | Eridanus |
| 37 | Fornax |
| 38 | Gemini |
| 39 | Grus |
| 40 | Hercules |
| 41 | Horologium |
H–P
| No. | IAU constellation |
|---|---|
| 42 | Hydra |
| 43 | Hydrus |
| 44 | Indus |
| 45 | Lacerta |
| 46 | Leo |
| 47 | Leo Minor |
| 48 | Lepus |
| 49 | Libra |
| 50 | Lupus |
| 51 | Lynx |
| 52 | Lyra |
| 53 | Mensa |
| 54 | Microscopium |
| 55 | Monoceros |
| 56 | Musca |
| 57 | Norma |
| 58 | Octans |
| 59 | Ophiuchus |
| 60 | Orion |
| 61 | Pavo |
| 62 | Pegasus |
| 63 | Perseus |
| 64 | Phoenix |
| 65 | Pictor |
P–V
| No. | IAU constellation |
|---|---|
| 66 | Pisces |
| 67 | Piscis Austrinus |
| 68 | Puppis |
| 69 | Pyxis |
| 70 | Reticulum |
| 71 | Sagitta |
| 72 | Sagittarius |
| 73 | Scorpius |
| 74 | Sculptor |
| 75 | Scutum |
| 76 | Serpens |
| 77 | Sextans |
| 78 | Taurus |
| 79 | Telescopium |
| 80 | Triangulum |
| 81 | Triangulum Australe |
| 82 | Tucana |
| 83 | Ursa Major |
| 84 | Ursa Minor |
| 85 | Vela |
| 86 | Virgo |
| 87 | Volans |
| 88 | Vulpecula |
These 88 names are the complete IAU set, not a selection of the most famous patterns. Some are large and conspicuous; others are faint or difficult to recognize without a detailed chart. A name’s inclusion does not guarantee that the whole region is visible from every latitude.
Constellation, asterism and star pattern: the terms compared
| Term | What it means | Example |
|---|---|---|
| Constellation | An IAU-defined area of sky with coordinate boundaries. | Ursa Major as a complete official region. |
| Asterism | A widely recognized star pattern that is not itself an official constellation area. | The Big Dipper or Plough within Ursa Major. |
| Illustrated figure | Lines or artwork used to make a constellation easier to recognize; artists may draw them differently. | Different outlines for Orion or Leo in different atlases. |
| Cultural grouping | A sky grouping from a particular historical or Indigenous tradition, which may not match IAU borders. | Regional traditions that organize the same stars in other ways. |
The Summer Triangle is another useful example: it is an asterism whose bright stars belong to three different constellations. Calling it a constellation would blur the distinction between a recognized pattern and an official sky area.
Asterisms are still valuable observing tools. A bright, memorable pattern can help you point a chart in the right direction, but it is only a signpost. Once you find it, trace the surrounding region and consult the coordinate grid if you need the formal boundary.
Latin names, English labels and genitives
Use the Latin name when you need an unambiguous catalog or chart reference. English labels are useful for explanation, but they can vary between sources. The IAU also assigns a genitive form, the possessive used in star designations. For example, Hamal in Aries is Alpha Arietis—literally, the alpha star of Aries.
Genitives explain why a star’s catalog name may not look like the constellation’s ordinary name. They are grammatical forms used in designations, not additional constellations. When copying a name into astronomy software, preserve the standard spelling and, where possible, the IAU three-letter abbreviation.
There is no single official pronunciation for a constellation name. An atlas may provide a pronunciation guide, but different astronomical communities can use different reconstructed Latin or anglicized sounds. Spelling and abbreviation are more reliable identifiers than trying to enforce one spoken form.
How to determine which constellations you can see
The 88-name list is global; your visible subset is local and changes with time. Latitude, hemisphere, date, clock time, horizon obstructions, light pollution, clouds and moonlight all affect what is practical to observe. NASA summarizes the central rule: the time of year and your location determine which constellations you can see. Northern and Southern Hemisphere observers do not have identical skies.
“Visible” can mean two different things. A region may technically be above your mathematical horizon while its lowest stars are blocked by trees or buildings. It may also be above the horizon but too faint to recognize under city lights or haze. A useful observing plan therefore combines a chart with a realistic view of your horizon and sky conditions.
A reliable observing workflow
- Set your location. Use the observing site’s latitude and longitude, not merely a country or time zone. A city-center setting can differ from a dark-sky site several kilometers away.
- Set the date and local time. Constellations rise and set as Earth rotates, while the night sky changes through the year as Earth orbits the Sun.
- Choose a current sky chart. Select a planisphere or digital chart that matches your hemisphere and date. Rotate it so its horizon matches the direction you are facing.
- Start with a bright landmark. A prominent star or easily recognized asterism can act as a signpost. Remember that the asterism may occupy only part of an official constellation.
- Match the outline, then check the boundary. Use the drawn figure to identify the region visually. For scientific work, switch to coordinate grids or the IAU boundary data; the artwork alone cannot establish whether an object lies inside the border.
- Allow for conditions. Give your eyes time to adapt, move away from direct lights and use averted vision for faint stars. A constellation can be above the horizon but effectively invisible under bright urban skies.
- Record what you used. Note the site, date, local time, chart edition or app and the direction you faced. Those details make your observation repeatable and explain why another observer may report a different visible subset.
A static list cannot tell you what is visible tonight. Any “visible now” answer must state the observer’s location, date and time, and should account for weather and local horizon conditions.
Using official charts and coordinates
For casual identification, a printed or screen chart with constellation figures is sufficient. For astronomy software, research notes or a catalog query, use the IAU’s boundary-coordinate resources. Right ascension and declination are the celestial equivalents of longitude and latitude; the published boundary files use the J2000 reference epoch.
J2000 gives the coordinate data a stated reference frame and epoch. It is a technical specification for mapping, not a promise that the sky appears fixed in one orientation from your backyard. Earth’s rotation makes the sky move across the night, so a chart still needs the observing date, time and location to show what is above the horizon.
The IAU chart table is useful when a project needs more than a name: it brings together the Latin form, pronunciation guidance, standard abbreviation, English label, genitive and chart material. Use the official boundary text when a program must classify an object by coordinates, and use the illustrated chart when a person needs a visual route to the region.
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1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteWhen sharing an IAU chart, retain its attribution under the stated Creative Commons Attribution 4.0 terms. Do not redraw a chart and imply that the connecting lines are official borders. The border is the coordinate data, not the artwork.
Why familiar drawings can be misleading
- Different line conventions: two atlases may connect different stars while naming the same constellation.
- Unequal distances: apparent neighbors can be at widely different distances from Earth.
- Partial visibility: from mid-latitudes, a constellation may rise only partly above the horizon.
- Uneven brightness: faint stars that complete an illustration may disappear in light pollution.
- Border confusion: an object can be inside a constellation’s official area without lying on its pictured figure.
- Scale and orientation: a chart may show a wide region while your unaided view covers only a small portion; rotating the chart to match the direction you face prevents mirror-image mistakes.
These limitations are reasons to combine several views rather than discard charts altogether. Start with the recognizable pattern, confirm neighboring bright stars, and then use coordinates or an official boundary file when precision matters.
How to use the list for learning
Learn a few anchor regions first, then expand outward. Identify a bright pattern, note the neighboring constellations on a chart, and practice locating the same area on different nights. Keep the Latin spelling in your notes so catalog searches remain consistent, and record the date, time and location whenever you make an observation.
For a reference sheet, include the 88 names, the IAU three-letter abbreviations from its chart table, a coordinate grid and a hemisphere-appropriate map. Keep the list separate from asterisms such as the Big Dipper and Summer Triangle so beginners do not mistake a visual shortcut for an official boundary.
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A printed astronomy star chart is a practical companion to this list because it supplies the location- and season-aware context that a static alphabetic list cannot. Choose one designed for your hemisphere and observing latitude, and check that its date range or update information suits your use. A telescope is not required to identify a constellation; naked-eye observation and a chart are enough to learn the principal patterns.
What the 88-constellation system does—and does not—claim
The IAU system provides one international standard for dividing the sky. It does not erase older, regional or Indigenous sky traditions, many of which group stars differently and attach their own stories and uses to them. Treat those systems as distinct cultural frameworks rather than as incorrect versions of the IAU list.
Nor does an official constellation name confer ownership of an individual star. The IAU does not recognize commercial star-naming certificates as official astronomical names. A paid certificate can be a personal gift, but it does not change a star’s catalog designation or place it in a new constellation.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Common mistakes to avoid
- Counting patterns instead of regions: the Big Dipper and Summer Triangle are useful asterisms, not extra entries beyond the 88.
- Assuming every star in a drawing belongs to one physical group: visual alignment does not establish shared distance or origin.
- Using a seasonal list as a universal answer: visibility changes with latitude, hemisphere, date, time and local conditions.
- Treating artwork as a border: only the coordinate-defined region answers whether an object is officially in a constellation.
- Flattening cultural traditions into one system: the IAU list is an international standard, not a replacement for other sky knowledge.
- Confusing a name with a pronunciation rule: the IAU provides guidance but no single universally correct spoken form.
Further questions observers ask
The answers below summarize the practical points that most often cause confusion when using an all-constellation list.
Frequently Asked Questions
How many official constellations are there?
The International Astronomical Union recognizes 88 constellations covering the entire sky. The set of names was agreed in 1922, and the coordinate boundaries were approved in 1928 and published in 1930.
What makes a constellation official?
Its sky area has an IAU-defined boundary expressed with celestial coordinates. The lines or artwork used to connect stars are illustrations and can vary between atlases.
Are the stars in one constellation physically related?
Not necessarily. Stars that appear close together from Earth can be at very different distances and may have no physical connection.
Is the Big Dipper one of the 88 constellations?
No. The Big Dipper, also called the Plough, is an asterism within the official constellation Ursa Major.
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What is the Summer Triangle?
It is an asterism, or recognized pattern, whose bright stars come from three different official constellations. It is not a separate constellation area.
Why can two star charts draw the same constellation differently?
The IAU standardizes the area, not one mandatory stick-figure design. Artists and atlases can choose different connecting lines while referring to the same coordinate region.
Can I see all 88 constellations from my home?
No single location and night provides a universal view of all 88. What is observable depends on latitude, hemisphere, season, date, time, horizon and sky conditions; some regions may be below the horizon or too faint to recognize.
How do I find a constellation tonight?
Set your exact location, date and local time in a current planisphere or digital chart, orient its horizon to the direction you face, begin with a bright landmark or asterism, and then compare the surrounding stars. Use coordinate grids for a formal boundary check.
What are right ascension and declination used for?
They are the coordinate system used to describe positions on the celestial sphere, analogous to longitude and latitude on Earth. The IAU boundary files specify the constellation borders in right ascension and declination using the J2000 reference epoch.
Do constellation names have official pronunciations?
The IAU states that there is no single correct way to pronounce a constellation name. Standard Latin spelling and the IAU abbreviation are more dependable for written identification.
What is a constellation’s genitive?
It is the possessive form used in star designations. Hamal in Aries, for example, is Alpha Arietis, meaning the alpha star of Aries.
Are English names and Latin names interchangeable?
English descriptions can help readers recognize a subject, but the Latin name is the standardized reference key used by the IAU chart material. Keep the Latin spelling for catalogs and software.
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The IAU chart artwork is released under a Creative Commons Attribution 4.0 license. Reuse it with the required attribution, and do not describe the drawn lines as official borders.
Does buying a star-naming certificate give a star an official name?
No. The IAU does not recognize commercial star-naming certificates as official astronomical names. They do not alter a star’s catalog designation or constellation membership.
Do I need a telescope to learn the constellations?
No. Naked-eye observation and a suitable chart are enough to identify the main patterns. A telescope is optional equipment for other observing goals, not a requirement for using this list.
The Bottom Line
The IAU’s 88 constellations are coordinate-defined regions covering the whole sky. Learn their Latin names from the complete list, use asterisms only as visual signposts, and rely on a location- and date-specific chart for visibility. When precision matters, consult the IAU’s J2000 boundary coordinates; when teaching or observing casually, remember that the illustrated figure is a guide, not the border.
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