Mira (star)

Mira A
Spectral	M7 IIIe
Type	Giant
Multiple	Binary
Luminosity	~9000 LSol
Absolute magnitude
Mag Terra	3.04
Temperature	~3000° K
Mass	1.18 MSol
Radius	~350 RSol
Companion	Mira B

Mira B (VZ Ceti)
Spectral	DA
Type	White Dwarf (Degenerate Dwarf)
Multiple	Near Companion
Luminosity	LSol
Absolute magnitude
Temperature	° K

The star Mira (otherwise known as Omicron Ceti and Collum Ceti) is a pinkish-orange red giant star of spectral type M7 which lends its name to the class of stars known as Mira-type variables. It is orbited by a degenerate dwarf companion of spectral type DA that is accreting material from the primary star.

Description (Specifications)

Mira is a binary star system consisting of a red giant star (Mira A) and a high temperature "white dwarf" degenerate companion (Mira B) that is accreting mass from the primary star.

• Mira A is an oscillating variable star currently on the asymptotic giant branch of the HR-diagram in the thermally pulsing AGB phase, each pulse lasting a decade or more, with approximately 10,000 years passing between each pulse. The pulsations also cause dynamic instability in Mira A which result in dramatic changes in luminosity and size over shorter and irregular time periods.
• The overall shape of Mira A changes over time, exhibiting pronounced departures from symmetry caused by bright spots on the surface that evolve their shape on a 3–14 month timescale.
• Mira A exhibits a plume-like feature pointing toward the companion star, Mira B, which is a direct exchange of mass along a spiral bridge of gas from Mira A in the direction of Mira B.
• The orbital period of Mira A and B is roughly 500 years, and the stars are separated by an average distance of ~100AU.
• Mira B is known to be erratically variable itself, its fluctuations related to its accretion of matter from Mira A's stellar wind.
• A protoplanetary disk has formed around Mira B which is apparently derived from captured material from Mira A.

History & Background (Dossier)

The Mira star system is approximately 91.7pc from Terra, and is located in a Rimspinward direction from Terra at bearing 167.8^o Galactic Longitude and -58.0^o South Galactic Latitude.

References & Contributors (Sources)

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

This page uses content from Wikipedia. The original article was at Mira_B. The list of authors can be seen in the 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 Far Future Enterprises or by permission of the author. The page history lists all of the contributions.

• MegaTraveller CD-ROM: Preliminary Traveller Map (Hand-drawn)
• EXTERNAL LINK: SIMBAD @ University of Strasbourg: [1]
• EXTERNAL LINK: STARS (University of Illinois - Prof. Jim Kaler): [2]
• Traveller Wiki Editorial Team
• Author & Contributor: WHULorigan
• Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science