# After Dark – Part 3

Did you know that if planet Earth were invaded by angry hungry aliens from a distant Death Star ship, the best offering to avoid possible violence or slavery believe it or not would be to hand over our silicon-based sand and rocks?  Which way do all of our planets in our Solar System rotate?  Have you ever wondered why comets such as Halley’s Comet, Pons-Gambart, and Ikeya-Zhang Comets take 75, 188, and 366 earth-years respectively to come around?

Questions like these and their answers fascinated me camping outside as a boy looking up into the night sky with astonishment.  How far away is that star, I would ask myself, which lead to another question and another.  Limitless.

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To enlarge click image

A 100-foot telescope and multi-million dollar observatory are not necessary to begin an intermediate knowledge of the celestial.  Your outstretched arm, hand and fingers can suffice in determining an object’s angular size.  Clamp your hand in a fist.  Across your knuckles is about 10 degrees.  Don’t believe me?  Taking that fist and starting at the horizon count how many “fisted-hands” it takes to count upwards to straight up, or zenith (the top of the sky).  It will be about nine hands, or 90 degrees.  Three fingers together are about 5 degrees across and one finger, like the pinky finger, will be about 1 degree.  A full moon then, when using this form of measurement will be about a half-degree (0.5°).

Finding the position of an object in the sky is a bit more difficult.  If you don’t carry around a Cross Staff, or Astrolab, or even what amateur golfers use today:  a GPS app; if you can find due north then you can still navigate the sky with your hand.  The azimuth, or angular measurement parallel to the horizon in a spherical coordinate system, determines the cardinal points:  north, south, east, and west.  North is of course 0 degrees, east will be 90 degrees, south is 180 degrees, and due west will be 270 degrees.  The angle above the horizon will be, you guessed it, altitude.  Keeping our basic sky-gazing simple, when measuring from the horizon to the zenith, only 0-90 degrees is needed.  Now you have the quickest most convenient tools to examine the never-ending sky.

A simple pair of binoculars can reveal more of the heavens beyond your naked eye.  If you surveyed the full moon, you could easily find many craters or the four brightest moons of Jupiter.  With the same binoculars you might be able to find Saturn’s brightest and biggest moon:  Titan.  If you want to see even more of the night sky, you will have to have binoculars stronger than 7x (times); in other words massively big and expensive type binoculars that will require a tripod or something steady and stationary to mount your 8x plus binoculars.  Beyond high-powered binoculars gets us into complex telescopes and well beyond the scope of this post.

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##### Under the Stars

Some star-maps, a flashlight, items to keep you comfortable or warm, and some patience will be all you need to find stars, constellations, and other sorted celestial performers.  The further away from light-pollution you can get (i.e. large towns or cities) the better.  Finding cardinal points is easiest with a compass or map; they both work fine.  If you can remember where on the horizon the Sunset took place, then you have a general idea which direction is west.  Keep in mind though the seasonal factors:  during winter the Sun recedes a little south of due west and during summer it sets a little north of due west.  In spring and fall, the Sun sets quite close to due west.

If you can view your sky maps with a red-lighted flashlight, then your pupils won’t close up in its light.  A normal white flashlight will cause your views from map-to-sky and back again to be greatly hindered by your widening and retracting pupils causing delays in their adjustments and testing your patience.  Having red-lenses to cover the bulb or flashlights using a “red-LED” bulb can be purchased at most camping-sporting stores.  Also, when you’ve been out a few times and can easily locate previous stars and/or constellations, moving on to unexplored areas becomes quicker and easier as your mapping-spotting skills improve.

One more star-gazing tip:  A clear sky is usually pretty cold relative to your latitude.  The further away you are from the equator, the colder the clear sky will be and the quicker your sitting-still body will get.  Dress warmer than normal, a toboggan or hat might be good, and even bring along a Thermos of hot soup or tea, or as I often do, a warm stout toddy!  If you want to “impress” a certain co-stargazer, bring along reclining folding-chairs and a quilt.  He or she will be in for a superb relaxing long evening of fun.

The following four seasonal sky maps are near 35 degrees north latitude in North America; in other words, a straight line from Lompoc, CA to Fayetteville, NC.  Sky maps from your particular location can be found on the internet or from a local nearby planetarium store.  The six bi-monthly descriptions below are incorporated into the flow or movement of the sky maps.

Sirius:  The Five-month King of Stars

This map shows the winter sky at 2am December 1; midnight January 1; and 10pm February 1. Image – Roen Kelly, astronomy.com

From late December through mid-April, in the southeasterly sky, the brightest star of all stars in our sky is Sirius.  It is the brightest because it is the closest star to Earth:  about 8-light years away and closing.  Yes, you read correctly, Sirius is getting closer to our Solar System and will be noticeably brighter in about 50,000 to 60,000 years.  After that it will begin moving away, but for the next 200,000 years or so it will always be the King of All Stars.  During winter and spring Sirius is a great reference point if you are just starting out as a new astronomer.

Serving King Sirius and moving to the west and slightly up is his Viceroy Rigel, then further up are Viceroys Betelgeuse (better known as Beatlejuice), Procyon to the east, and finally back toward the west and near straight up is  Aldebaran.  Straight up, or near zenith, and more north is his lone Viceroy Capella.  These five stars represent magnitudes about 2.5 times less than Sirius but are so bright they can all be spotted in a large city with light-pollution.  King Sirius’ “court” is the primary reason the winter skies are the favorite season for stargazers; they jump out to you!

Galaxies Galore and A New Prince

Heading into spring (March – early May) you’ll notice that Sirius and his viceroys have moved toward the western horizon.  Back to the southern horizon is a darker starless sky by comparison.  Yet due east near the horizon comes the newest viceroy or Prince:  Arcturus which has been led by the largest cluster of galaxies – almost halfway up to the zenith – called the Virgo Clusters.  They include more than 1,300 galaxies.  Off toward the north and halfway to zenith you can find the Big Dipper.

Another Viceroy and King Sirius Departs

1am March 1; 11pm April 1; 9pm May 1. Add one hour for daylight-saving time. Image – Roen Kelly, astronomy.com

While Sirius drops down behind the western horizon and Procyon and Capella soon follow, the newest member to the court arrives:  Viceroy Vega.  Almost to the northeastern horizon, Vega’s brightness equals that of his predecessors and brings with him the Northern Cross with Deneb (touching the horizon) as its crown.  It is now May through early July.  Move to the southeastern horizon close to Earth’s surface, and the claws of Scorpius have appeared with Antares as its heart.  Near the zenith sits Arcturus, 2nd in command for about two-plus months, while Sirius vacations in his summer palace doing “unseen” kingly jollies for the next four.

The Milky Way’s Majesty

1am June 1; 11pm July 1; 9pm August 1. Add one hour for daylight-saving time. Image – Roen Kelly, astronomy.com

July and August are the best times to see the center of our galaxy particularly with binoculars.  Like a following royal parade, Vega brings along in the eastern sky not only Altair, a star slightly brighter than the previous Deneb, but also the globular-cluster M13 near zenith, and the star-clusters M11, M39, and the best clusters M6 and M7.  And as if that wasn’t enough, the nebulas M8, M20, and M17 between Scorpius and Sagittarius to the south (about 10° up from horizon), round off the fat center of our majestic Milky Way.

Fall’s Tranquility?

The gaudiness of summer and the Milky Way drift into the southwest horizon causing many astronomers to say the night sky is the tamest from September through late October.  It is perhaps no coincidence then that fall and October are celebrated as Halloween, or hallow the dead and dying.  The Viceroy Arcturus has all but vanished behind the western horizon, leaving only Prince Vega near the zenith.  The return of Capella and the first of King Sirius’ court are probably not yet visible to the northeast.  A seemingly dark “blanket” ensues.

1am September 1; 11pm October 1; 9pm November 1. Add one hour for daylight-saving time. Image – Roen Kelly, astronomy.com

Not to worry, as all great exciting events take place to the south – sexual overtones intended – magnitude 1.16 star Fomalhaut rises out of Earth’s vagina to remind us that with persistence comes birth… and for better or worse, MANY MORE THINGS to come!  Can I get an Amen!?  Because Fomalhaut is the lone bright star in this part of the sky, many space agencies and orbital spacecraft engineers use the star as a point of reference for their machines.  Their computerized satellites or crafts are programmed to find Fomalhaut and then align themselves.  There is less of a chance for other mistaken bright stars nearby; a computer optic no-brainer if you will.

Because the heavens are darkest during this time of year, many scientist and expert stargazers use their high-powered telescopes to search out darker phenomena.  This goes to show that a certain darkness is needed to truly see the stars.

The Mira and Algol Light Show

As King Sirius’ court of brightest stars rise again in the east, with a set of binoculars (certainly a telescope) a dance or battle can be seen more clearly between two stars; technically between the star Mira “The Wonderful” and the double-star system Algol “The Winking Demon.”

Mira is in the middle of Cetus the Whale, a quiet faint constellation of stars about 45 degrees up from the southeast horizon between Aquarius (to the southwest) and Orion (to the lower east) and the returning Aldebaran, Rigel, and Betelgeuse.  Mira fades from a semi-bright magnitude 2 to a very dim magnitude 10 in less than eleven months.  Mira means “the Wonderful” in Arabic and signifies her dramatic leaving and return.  This happens due to her near-death lifespan and being unstable, pulsating prior to burn-out.  When Mira is big and cool, most of its light is only visible in the infrared spectrum.  When she is small and hot, she radiates most of her light at the far end of the visible spectrum; red in a telescope.  Mira has quite possibly already turned into a planetary nebula then white dwarf, but we won’t witness this for another 35,000 Earth-years because she is about 350-light years away.

Algol in Arabic means “the Demon” and they called the double-star system this because astonishingly one star eclipses the other every 2.87 days!  This makes its brightness dip from a 2.2 magnitude to a 3.5 magnitude creating the winking demons.  This change can be seen by the naked eye.  Algol can be located up about 60 degrees from the easterly approaching the zenith during mid-November to mid-January.

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Other Resources

As you may have noticed, it is impossible to include all the major fascinating parts of stargazing and our cosmos in a 1,000 word blog-post – the commonly recommended length.  This post is around twice that long.  Therefore, I am including further website resources to explore should you want to know more, even become a well-informed astronomer.

www.astronomy.com  The site I used for the sky maps.
www.darksky.org
www.science.nasa.gov
www.skyandtelescope.com
www.hubblesite.org

For the serious star-preneur, astronomy software for purchase:
Starry Nightwww.starrynight.com
The Skywww.bisque.com  for the mega-serious!

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P.S.   To answer the two initial questions in the beginning all our planets rotate counter-clockwise around the Sun.  And about those once-in-a-lifetime comets and why they take so long to return and why they keep coming back… it is because of our Sun’s gravitational control.  It extends out to the Kuiper Belt which is well beyond the outer planet Neptune, or about 2.8 billion miles from our Sun.  Perspective:  and our Sun is one of the smallest Suns in the galaxy and cosmos!

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