Delta Cephei (star)

Delta Cephei Aa
Spectral	G1 Ib
Type	Weak Supergiant
Multiple	Quaternary
Luminosity	~2000 LSol
Absolute magnitude	-3.47
Mag Terra	~ 4.0
Temperature	~6000° K
Mass	4.5 MSol
Radius	44.5 RSol
Companion	Delta Cephei Ab

Delta Cephei Ab
Spectral
Type
Multiple	Binary Companion (A-Component)
Luminosity	LSol
Absolute magnitude
Temperature	° K
Mass	0.5 MSol

Delta Cephei Ba
Spectral	B8 IV
Type	Subgiant
Multiple	B-Component
Luminosity	500 LSol
Absolute magnitude
Mag Terra	7.5
Temperature	° K
Companion	Delta Cephei Bb

Delta Cephei Bb
Spectral
Type
Multiple	Binary Companion (B-Component)
Luminosity	LSol
Absolute magnitude
Temperature	° K

The star Delta Cephei, also known as Alrediph is a Yellow-white supergiant star of spectral type G1 Ib, with a companion Ab-component, orbited by a blue subgiant star of type B8 IV with its own companion Bb-component .

Description (Specifications)

Delta Cephei is a pair of double stars, the brightest component of which (Delta Cephei Aa) is the historically important variable star which gave its name to the class of stars known as the "cepheid variables". Delta Cephei was discovered in -2737, or 1784 A.D. in Terran dating. At least thirty times the diameter of Sol or more, its apparent magnitude varies from a maximum of 3.3 to a minimum of 4.5 in highly regular periods of 5 days, 8 hours, 47 minutes and 39 seconds T.S. (Terran Standard). It is the oldest of the known cepheid variables. Delta Cephei's dim Ba-companion is a blue star which has an apparent magnitude of 7.5.

• The Ab-companion orbits Delta Cephei Aa with a period of about 6.03 years with an eccentricity of e=0.647, approaching as close as 2.0 AU at periastron.
• The entire B-Component system is separated from the A-Component system by about 11,000 AU, and orbits it with a period of approximately 300,000 years.

The Delta Cephei star system lies approximately 282pc from Terra, and is located in a Corespinward/Spinward direction from Terra at bearing 105.2^o Galactic Longitude and +00.5^o North Galactic Latitude.

History & Background (Dossier)

Delta Cephei is the primary star of the world Delta Cephei/Araniopa (The Beyond 2922).

Image Repository

TravellerMap (T5SS):
[1]

References & Contributors (Sources)

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This page uses content from Wikipedia. The original article was at Cephei Delta Cephei. The list of authors can be seen in the Cephei&action=history page history. The text of Wikipedia is available under the Commons Attribution-ShareAlike 3.0 Unported License.

This list of sources was used by the Traveller Wiki Editorial Team and individual contributors to compose this article. Copyrighted material is used under license from Mongoose Publishing or by permission of the author. The page history lists all of the contributions.

• EXTERNAL LINK: SIMBAD @ University of Strasbourg: [2]
• EXTERNAL LINK: STARS (University of Illinois - Prof. Jim Kaler): [3]
• Author & Contributor: WHULorigan