November night skies
With most of the evenings clear, October turned out to be great for stargazing . As I write this installment of the column, I am anticipating another great show from the Leonid meteor shower. I just hope the bright moon does not spoil things this year.
The North Star is easy to find if you can locate the Big Dipper in the northern sky. Look for the “pouring end” of the dipper and draw a line from the star at the bottom of the bowl through the lip. Follow that line about halfway up in the sky. Just to the side of that imaginary line is a bright star, the North Star. Watch it through the night and over the seasons. All of the other stars in the sky rotate around this point in space.
The North Star is our constant companion throughout the night and the seasons. It never sets nor does it rise. It is always there. If you drew a line from the South Pole to the North Pole, that line would point toward the North Star. Hence it is also called Polaris, the polar star. In reality, the star is slightly off the pole; therefore, the Earth’s North Pole makes a small circle around the North Star, about 1.5 degrees across.
Not only does the Earth tilt on its axis, causing the seasons, but the direction of that tilt, relative to the galaxy, wobbles in a twenty-six-thousand-year cycle. Over the next hundred years, that circle we make around the North Star will shrink in size. Our North Pole will point almost exactly at the North Star in the year 2100. Thousands of years from now, the North Star will have moved and will be well off the pole and other stars will take their place as the polar star. In twenty-some thousand years, Polaris will again be the North Star.
Many people think that the North Star is the brightest in the sky. Actually, it is the fortieth brightest star with a magnitude of 2.02 (lower numbers are brighter). Its dimness is due to the distance it is form Earth, 430 light years. This super giant is 2,200 times brighter than our Sun. If you watch very closely over the course of about four days, you might detect a slight change in the star's brightness. Because it is an old star that has nearly depleted its hydrogen fuel, it pulsates slightly.
So next time you look at the North Star, you will know that it is not the one and only North Star and it is not as rock steady as you once thought.
You may not have noticed, but a meteor shower is in progress. The autumn Northern Taurids are active from October 12 through December 2. The peak of the shower is broadly spread out from November 4 through 7. Don't get too excited over this event; it is more like a drizzle than a shower. The maximum usually produces about seven meteors per hour.
There will be a penumbral eclipse of the moon on November 20. For New Mexico, the eclipse starts just before the moon rises at sunset. A penumbral eclipse is one during which the moon does not enter the full shadow cast by the Earth. The moon will get dimmer and a bit redder, but it will not get completely dark.
Saturn rises mid-evening in November. It resides in Taurus and rises just ahead of Orion.
Jupiter peeks above the horizon after midnight and is situated between Cancer and Leo.
Look quick, low in the east, in the morning twilight for a glimpse of Mercury on November 1 and 2.
Late in the month, Venus and Mars will rise side by side in the morning sky about 6:00 a.m.
As a special treat, night owls may take a look at the position of Saturn and the moon about 11:00 p.m. on November 21. The moon will be just west of Saturn. Watch the relative position of the moon as it slides past Saturn. By sunrise, the moon will be well east of the planet. With Saturn as a steady reference in the sky, you can actually see the moon move in its orbit.