| Delta Cephei |
Article Index for Delta |
Website Links For Delta |
Information AboutDelta Cephei |
| CATEGORIES ABOUT DELTA CEPHEI | |
| cepheus constellation | |
| bayer objects | |
| cephei, delta | |
| cepheid variables | |
| binary stars | |
| yellow supergiants | |
| yellow-white supergiants | |
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It is the prototype of the Cepheid Variable s. Its variability was discovered by John Goodricke in 1784 . Unlike the Eclipsing Binary Algol , Delta Cephei's variability is due to pulsation of the star. It varies from Magnitude 3.6 to 4.3, and its Spectral Type also varies, from about F5 to G3. The period is 5.36634 days; rise to maximum is quicker than the subsequent decline to minimum. Knowing the distance of Delta Cephei and others in its class is fundamental to calibrating their Period-luminosity Relationship ; unfortunately, these efforts were until recently marred by only fair Parallax accuracy. In 2002 however, the Hubble Space Telescope was used to determine the distance to Delta Cephei (and RR Lyrae , another Standard Candle ) within ~4%: 273 parsecs, or 890 light-years. Reference: |
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