Delta Cephei


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Delta Cephei

(see -fee-ÿ) See Cepheid variables.

Delta Cephei

[′del·tə ′sef·ē‚ī]
(astronomy)
A cepheid variable, from which the name of this type of star is derived; it has a period of 5.3 days.
References in periodicals archive ?
Last month I profiled three classic variable stars prominently visible in fall (Delta Cephei, Mira, and Algol) and mentioned that three of the 20th century's greatest amateur astronomers were avidly enthusiastic variable star observers.
Examples of this behaviour are classified as delta Cephei, RR Lyrae and delta Scuti stars according to their position in the H-R diagram and the nature of their variation.
The star in the study is Delta Cephei, which is the namesake for the entire class of Cepheids and was discovered in 1784.
I wrote about Delta Cephei in last October's installment of this column.
It is also home to two important variable stars; delta Cephei, prototype of the Cepheid variables, and mu Cephei, the semi-regular Garnet Star named by Sir William Herschel and one of the reddest naked eye stars in the sky (although this is totally lost on the colour-blind Director).
In last month's column I argued that Cepheus was underrated and described wonders in the Cepheus Milky Way's "spur to Kurhah" and "Delta Cephei triangle." But there's more in Cepheus: the oldest and most northerly open star cluster NGC 188; the Cepheus-Cygnus border "odd couple," galaxy NGC 6946 and open cluster NGC 6939; and yet another lovely double star Beta ((3) Cephei (Alfirk).
John Coodricke discovered the variability of Delta Cephei, the prototype of the class, in 1784.
Delta Cephei is a yellow-giant star that changes from magnitude 3.5 to 4.4 and back over 5.4 days.
Extended cocoons of gas resolved around the Cepheid variables Polaris and Delta Cephei suggest a connection between these stars' pulsations and the shedding of mass, with far-reaching implications.
Using the Very Large Telescope Interferometer in Chile and the CHARA Array on California's Mount Wilson, an international team resolved infrared cocoons around Polaris, Delta Cephei, and L Carinae.
Though the archetype Cepheid variable, Delta Cephei, lies too far north for most Southern Hemisphere observers, a good substitute rides high on the meridian at this time of year: Kappa (k) Pavonis.
It is a Cepheid variable, meaning it belongs to the important class named after Delta Cephei. (That star's fluctuations were first detected in 1784 by English amateur John Goodricke, another great pioneer of variable-star astronomy.)