What kind of star is Scheat?
Scheat, catalogued as Beta Pegasi (β Peg), appears in the official constellation Pegasus. Its apparent visual magnitude is semiregular; roughly 2.3–2.7, while its estimated distance is about 196 light-years. Astronomers classify the object as M2.5 II–III. These labels describe temperature, luminosity class or system components; they should not be read as a claim that every naked-eye point is a single isolated star.
Beta Pegasi is a cool, evolved red giant or bright giant about 196 light-years away. Its atmosphere expands and contracts, producing semiregular changes in brightness and spectral appearance rather than a clock-like eclipse. Molecules can form in the cool outer layers, and radio/infrared observations trace material leaving the star in a stellar wind. Scheat is far larger than the Sun but less extreme than red supergiants such as Betelgeuse. Its parallax and angular-diameter measurements help constrain its physical radius. The apparent square shared with Markab, Algenib and Alpheratz has no dynamical meaning: Scheat's red colour and advanced evolutionary state are independent of the other corners.
The coordinate pair RA 23h 03m 46.46s, Dec +28° 04′ 58.0″ fixes the object's direction on the celestial sphere for the J2000 reference epoch. Right ascension works like celestial longitude measured in hours, while declination works like latitude north or south of the celestial equator. Proper motion and improved measurements can refine catalogue positions, but these coordinates are sufficiently precise for a finder chart or planetarium search.
Scheat data at a glance
| Proper name | Scheat | Catalogue designation | Beta Pegasi (β Peg) |
|---|---|---|---|
| Constellation | Pegasus | Apparent magnitude | semiregular; roughly 2.3–2.7 |
| Spectral or system type | M2.5 II–III | Estimated distance | about 196 light-years |
| Right ascension (J2000) | 23h 03m 46.46s | Declination (J2000) | +28° 04′ 58.0″ |
Values are rounded for an observer-friendly overview. Consult the linked SIMBAD record for component-level identifiers, bibliography, measurement provenance and newer catalogue values.
The name Scheat
From Arabic al-sāq, “the shin,” referring to its position on the traditional figure of Pegasus. Historical spellings vary because of transliteration.
The Arabic name describes a body part of Pegasus, showing how positional labels survived while constellation art changed across cultures and atlases. Scheat's variability was recognized through repeated photometry, and it remains accessible to visual observers. The IAU standardized the familiar spelling for Beta Pegasi. Its place in the Great Square also made it a routine reference point long before instruments could detect the atmosphere and wind of the giant itself.
Modern professional catalogues retain identifiers such as the Bayer designation alongside a proper name. The International Astronomical Union standardizes which name belongs to which component—an important distinction for systems whose combined light looks like one star from Earth.
How to find Scheat
Find the Great Square and identify its northwestern corner. Compare Scheat's warm tint with blue-white Alpheratz on the opposite northern corner. Regular naked-eye or binocular estimates can follow its subtle semiregular variation.
A northern autumn star visible from most inhabited southern latitudes as well. Visibility on a particular night still depends on latitude, season, time, horizon obstructions, weather and local light pollution. Use the interactive atlas below to check the surrounding field before observing.
Observation checklist
- Best from September through December evenings.
- Compare colour with Alpheratz at similar altitude.
- Use repeated estimates rather than expecting change within one night.
- AAVSO charts provide calibrated comparison stars for monitoring.
Interesting facts about Scheat
- Scheat is a semiregular variable star.
- It is an expanded red giant or bright giant.
- Its atmosphere is losing material through a stellar wind.
- It marks the Great Square's northwestern corner.
- The name refers to the shin of Pegasus.
Continue from Scheat into the night sky
Use the Pegasus constellation guide to place this star within its larger pattern. When you are ready to observe, compare dark-sky places, find a nearby observatory, or follow our practical guide to finding a star in the night sky. Symbolically registered names are kept separately in the searchable Star-Register catalogue.
Sources and further reading
Measurements are rounded for readability. Multiple systems, variable stars and distant supergiants can have component-specific or model-dependent values. Survey panels show photographic sky fields, not the physical surface of the star.