Harvard Classification Scheme
E567162
The Harvard Classification Scheme is an early 20th-century stellar classification system that organizes stars primarily by their spectral characteristics and temperatures into types such as O, B, A, F, G, K, and M.
Statements (43)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical classification scheme
ⓘ
stellar classification system ⓘ |
| adoptedBy | International astronomical community ⓘ |
| alsoKnownAs | Harvard spectral classification NERFINISHED ⓘ |
| associatedWith |
Edward C. Pickering
NERFINISHED
ⓘ
Harvard Computers NERFINISHED ⓘ |
| basedOn |
stellar spectra
ⓘ
stellar temperature ⓘ |
| classificationBasis | visual inspection of photographic spectra ⓘ |
| classifies | stars ⓘ |
| developedAt | Harvard College Observatory NERFINISHED ⓘ |
| developedFrom | Draper Catalogue of Stellar Spectra NERFINISHED ⓘ |
| developedInPeriod | early 20th century ⓘ |
| distinguishes |
cool red stars
ⓘ
hot blue stars ⓘ |
| field |
astronomy
ⓘ
astrophysics ⓘ |
| historicalSignificance | first widely adopted temperature-based stellar classification ⓘ |
| influenced | modern stellar spectral classification ⓘ |
| inUseDuring | 20th century ⓘ |
| legacy | letter sequence OBAFGKM retained in modern systems ⓘ |
| orderingCriterion | stellar surface temperature ⓘ |
| originCountry |
United States of America
ⓘ
surface form:
United States
|
| precursorTo | Morgan–Keenan classification system NERFINISHED ⓘ |
| primaryParameter |
ionization state of elements in stellar atmospheres
ⓘ
spectral line strength ⓘ |
| refinedBy | Annie Jump Cannon NERFINISHED ⓘ |
| spectralTypeACharacteristic | strong hydrogen Balmer lines ⓘ |
| spectralTypeBCharacteristic | hot, neutral helium lines and strong hydrogen lines ⓘ |
| spectralTypeFCharacteristic | weaker hydrogen lines, stronger metal lines ⓘ |
| spectralTypeGCharacteristic | strong metal lines, ionized calcium lines ⓘ |
| spectralTypeKCharacteristic | strong neutral metal lines, some molecular bands ⓘ |
| spectralTypeMCharacteristic | strong molecular bands, especially titanium oxide ⓘ |
| spectralTypeOCharacteristic | very hot, strong ionized helium lines ⓘ |
| standardizedBy | Annie Jump Cannon at Harvard College Observatory NERFINISHED ⓘ |
| temperatureOrder | O B A F G K M (hottest to coolest) ⓘ |
| usesSpectralTypes |
A
ⓘ
B ⓘ F ⓘ G ⓘ K ⓘ M ⓘ O ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.