This is an RS Canum Venaticorum variable and its brightness varies by 0.225 magnitudes, reaching a maximum of 3.70, with a period of 54.2 days . Such variability is theorized to occur because of tidal friction, which results in activity.
22.
Some of the moons of Jupiter are heated by tidal friction that way ( although the effect is likely to be much bigger when Jupiter is doing the pulling compared to the moon ! ) ( Ooohhh-Jupiter made the Wikipedia front page today!
23.
While the rate due to tidal friction alone is about 2.3 ms / cy, the uplift of Canada and Scandinavia by several metres since the last Ice Age has temporarily reduced this to 1.7 ms / cy over the last 2, 700 years.
24.
:: " Tidal friction, caused by the movement of the tidal bulge around the Earth, takes energy out of the Earth and puts it into the Moon's orbit, making the Moon's orbit bigger ( but, a bit pardoxically, the Moon actually moves slower ! ) ."
25.
The instability this causes would, however, probably also cause tidal friction in the rock, causing it to liquifiy, and over time ( millions of years ? ) the heavy elements ( metals and such ) would move to the geometric core and things would be back to normal.
26.
However, the slowdown of Earth's rotation is not occurring fast enough for the rotation to lengthen to a month before other effects change the situation : approximately 2.3 billion years from now, the increase of the Sun's radiation will have caused Earth's oceans to evaporate, removing the bulk of the tidal friction and acceleration.
27.
The " net " tide raised on Earth by the Moon is dragged ahead of the Moon by Earth's much faster rotation . "'Tidal friction "'is required to drag and maintain the bulge ahead of the Moon, and it dissipates the excess energy of the exchange of rotational and orbital energy between Earth and the Moon as heat.
28.
:: : : : : Since nothing is working on our orbit in the way that tidal friction works on our rotation, it is believed that the length of the year can be changing only if the gravitational constant is changing, as some theories suggest, but consensus says that's not happening either . & mdash; Tamfang 06 : 42, 16 August 2006 ( UTC)
