| Pulsating Variable Stars |
|---|
| TYPE OF VARIABLE |
SPECTRA | PERIOD (Days) |
MEDIAN ABSOLUTE MAGNITUDE |
AMPLITUDE (Magnitudes) |
DESCRIPTION | EXAMPLE | NUMBER KNOWN IN GALAXY* |
| Cepheids (type I) |
F to G supergiants |
3 to 50 | -1.5 to -5 | 0.1 to 2 | Regular Pulsation; period-luminosity relation exists |
δ Cep | 706 |
| Cepheids (type II) |
F to G supergiants |
5 to 30 | 0 to -3.5 | 0.1 to 2 | Regular Pulsation; period-luminosity relation exists |
W Vir | (About 50; included with type I) |
| RV Tauri | G to K yellow and red bright giants |
30 to 150 | -2 to -3 | up to 3 | Alternate large and small maxima |
RV Tau | 104 |
| Long-period (Mira-type) |
M red giants | 80 to 600 | +2 to -2 | >2.5 | Brighten more or less periodically |
ο Cet (Mira) |
4566 |
| Semiregular | M giants and supergiants |
30 to 2000 | 0 to -3 | 1 to 2 | Periodicity not dependable; often interrupted |
α Ori | 2221 |
| Irregular | All types | Irregular | <0 | Up to several magnitudes |
No known periodicity; many may be semiregular, but too little data exists to classify them as such |
π Gru | 1687 |
| RR Lyrae or cluster-type |
A to F blue giants |
<1 | 0 to +1 | <1 to 2 | Very regular pulsations | RR Lyr | 4433 |
| β Cephei or β Canis Majoris |
B blue giants |
0.1 to 0.3 | -2 to -4 | 0.1 | Maximum light occurs at time of highest compression |
β Cep | 23 |
| δ Scuti | F subgiants |
<1 | 0 to +2 | <0.25 | Similar to, and possibly related to, RR Lyrae variables |
δ Sct | 17 |
| Spectrum variables |
A main sequence |
1 to 25 | 0 to +1 | 0.1 | Anomalously intense lines of Si, Sr, and Cr vary in intensity with same period as light; most have strong variable magnetic fields |
α²C Vn | 28 |
| *According to the 1968 edition of the Soviet General Catalogue of Variable Stars. | |||||||
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Database Last Updated: September 02 2017 21:54:12.
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