Mu Centauri
Script error: No such module "Check for unknown parameters".
Mu Centauri, Latinized from μ Centauri, is a third-magnitude star in the southern constellation of Centaurus. With the stars ν and φ Centauri, it marks what has been traditionally portrayed as "dextro Latere" (the right side) of the Centaur.[1] The apparent visual magnitude of this star is 3.42,[2] making it one of the brighter members of the constellation. The distance to this star can be estimated directly using parallax measurements, which yield a value of roughly 510 light years (155 parsecs) from Earth.[1]
The spectrum of Mu Centauri is considered to be a standard for a B2 Be star with the stellar classification of B2V:e.[4] The 'e' suffix is used to mark the presence of emission lines, caused by a circumstellar disk of hot gas that was formed from material ejected from the star. Mu Centauri is a pulsating variable star that has multiple non-radial cycles with a primary period of 0.503 days. Three other pulsation cycles have a similar period, while two have a shorter interval of about 0.28 days. It undergoes outburst events that result in the transfer of additional material to the surrounding disk.[11] During these outbursts, the star can experience transient periodicities.[12] Mu Centauri is classified as a Gamma Cassiopeiae type variable star and its brightness varies from magnitude +2.92 to +3.49.[3]
This star is spinning rapidly, with a projected rotational velocity of 194,[9] km s−1 and is completing a full rotation in about 11.615 hours. The equatorial azimuthal velocity is around 85% of the critical velocity where the star would start to break up, resulting a pronounced equatorial bulge that is about 26% wider than the radius at the poles. Because of the oblate spheroidal shape of this star, the polar region is at a higher temperature than the equator—23,000 K versus 17,600 K respectively. Likewise, the gravitational force at the poles is greater than along the equator. The axis of rotation of the star is tilted by an angle of about (19 ± 3)° to the line of sight from the Earth.[8]
At an estimated age of nearly 20 million years,[7] this star is around 55–65% of the way through its evolutionary period on the main sequence of core hydrogen burning stars.[13] It has around nine[7] times the mass of the Sun and four[13] times the Sun's radius, but emits over 2,000[8] times as much energy as the Sun. The outer atmosphere has a mean effective temperature of 22,410 K,[13] giving the star a blue-white hue.[14]
This star is a proper motion member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[15]
References
- ↑ a b c d e f Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa474_2_653 - ↑ a b c d Cite error: Invalid
<ref>tag; no text was provided for refs namedapjs15_459 - ↑ a b c Cite error: Invalid
<ref>tag; no text was provided for refs namedgcvs - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedmk - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedrgcrv - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedAnderson2012 - ↑ a b c d Cite error: Invalid
<ref>tag; no text was provided for refs namedmnras410_1_190 - ↑ a b c d e f g Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa369_1058 - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedcoapa239_1 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedAguayo - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa333_125 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa411_229 - ↑ a b c Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa441_1_235 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedcsiro - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa216_1_44