pUniversing again

A chilly -5.5C outside, went out to the balcony anyways, for a breather (been writing records of progress all afternoon). Hazy sky tonight, and the moon is full or thereabouts but still, the Big Dipper came through. Pointed pUniverse at it and up came the names: Alkaid, Mizar, Alioth, Megrez, Dubhe, Merak and Phecda. Alkaid I already read about some weeks ago, so my eyes landed on Alioth, somehow.

Here's a summary of what wikipedia had to say about it:

Alioth or Epsilon Ursae Majoris (ε UMa, ε Ursae Majoris) is the brightest star in the constellation Ursa Major (despite its Bayer designation being merely "epsilon"), and at magnitude 1.76 is the thirty-first brightest star in the sky. Its traditional name Alioth comes from the Arabic word alyat, which means "fat tail of a sheep".

It is known as 北斗五 (the Fifth Star of the Northern Dipper) or 玉衡 (the Star of Jade Sighting-tube) in Chinese.

It is the star in the tail of the bear closest to its body, and thus a star in the handle of the Big Dipper, the one closest to the bowl.

Alioth is 81 light years from Earth. Its spectral type is A0p, where"p" stands for peculiar, as the spectrum of its light is characteristic of an Alpha Canum Venaticorum variable (must figure out what that is!).

Alioth, as a representative of this type, may harbor two interacting processes. First, the star's strong magnetic field separating different elements in the star's hydrogen 'fuel'. In addition, a rotation axis at an angle to the magnetic axis may be spinning different bands of magnetically-sorted elements into the line of sight between Alioth and the Earth. The intervening elements react differently at different frequencies of light as they whip in and out of view, causing Alioth to have very strange spectral lines that fluctuate over a period of 5.1 days.

With Alioth, the rotational and magnetic axes are at almost 90 degrees to one another. Darker (denser) regions of chromium form a band at right angles to the equator.

A recent study suggests Alioth's 5.1-day variation may be due to a substellar object of about 14.7 Jupiter masses in an eccentric orbit (e=0.5) with an average separation of 0.055 astronomical units.

Alioth has a relatively weak magnetic field, fifteen times weaker than α CVn, but it is still 100 times stronger than that of the Earth.