A Primer for Beginning Astronomers Answers to Whatsa or Howdoya.................?

This section is designed to answer astronomy questions in a very basic way. I'm not an expert but I have access to a lot of answers.
Click here to ask me a astronomy related question.
I will reply to all serious astronomy related questions. If this question is not already in 'Whatsa', I will add the question to this site along with the answer with your name. I'll also add other data about you, if you request it. (Club/School, City, Age, etc.)


Whatsa.....or.... Howdoya......

Star?

 A star is a very large ball of glowing hot gas. This gas is mostly Hydrogen.

Stars glow at different brightnesses for many different reasons; Distance, mass, and size. One of the reasons for different brightnesses is due to the different distances stars are from us. The closest star to us is the brightest star in the sky, the Sun. But the second closest star is dim, so there are other reasons for brightness. Another reason stars are of different brightnesses is because of their mass. A stars mass is measured by how many suns it would weigh. The more mass a star has, the brighter and hotter it is. Some stars are very fat and bright and weigh more than 50 suns. The last reason stars are of different brightnesses is due to their size. Our Sun is large to us, but some stars are so large that if they were sitting where our sun is, Earth's orbit would be inside, even Mars' Orbit would be inside the star.

(Question Whatsa Star? submitted by Andy Murry, age 10, Orangevale CA, stargazerdan@ulink.net).
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Light Year?

 A light year is a measurement of distance that equals about 5.88 trillion miles. Because light moves at a constant speed in space and moves very fast (186,000 miles per second), we can use it as a standard for measurement of distances to the stars. So instead of saying the closest star is around 23,520,000,000,000 miles away, we say its 4 light years (4ly) away (which is a lot easier to write).

(Question submitted by Will Murry, age 13, Orangevale CA,.
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Planet X?

 Planet X's existence and possible location was predicted from irregularities in the orbits of Uranus and Neptune. From those predictions Clyde W. Tombaugh at Lowell Observatory in Arizona searched for and found Pluto in 1930. But Pluto was far to small in mass to have caused the irregularities found, so they continued to search for Planet X. As time went on and scientific instruments improved (Voyager 2's measurement of Neptune's mass removed all discrepancies) it was found that all the irregularities could be accounted for and there was no Planet X (finding Pluto was purely chance!!! and hard work!). Now with even better instruments (Hubble, etc.) they are finding all sorts of tiny planets (or better called planetoids). These are very tiny planets or very large comet nucleus in orbit beyond Pluto (including Pluto & Charon, Pluto's moon???) and are believed to be the beginning of the Oort cloud or the Kuiper Belt (where Comets come from).

Question submitted by Brian Hedrick, age 13, January 1, 1996
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Anomaly?

 The definition of an anomaly is:
1. Deviation or departure from the normal or common order, form, or rule.
2. One that is peculiar, irregular, abnormal or difficult to classify.
3. In astronomy it is the angular deviation from the sun, of a planet from its perihelion (point of orbit nearest to the Sun). a anomalistic year is the time required for the earth to go from its perihelion point once around the Sun and back to that point. That time is 365 days, 6 hours, 13 minutes, 53 seconds. The longer time of this type of year (versus a solar year or sidereal year) is due to the slow rotation of the Earth’s orbit as a whole.
(Information from the Electronic version of The American Heritage Dictionary and Concise Columbia Electronic Encyclopedia)
So in space an anomaly would be anything that is not normal or common that usually causes us to rethink our favorite theories.

Question submitted by Persons Unknown, January 8, 1996
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R.A. Right Ascension?

 In most star maps stars and other objects are located with a coordinate system. This system uses Declination (DEC.) and Right Ascension(R.A.) to define its grid. Declination is the vertical coordinate measured in degrees North or South from the celestial equator. Right Ascensions the other part of the coordinate grid and is measured in hours, minutes, and seconds. This grid is fixed with the stars and (here is where I'm fuzzy with my own understanding) may be associated with sidereal time. A given star or other fixed object has a coordinate that does not change except through its own proper movement through space (maps have to be redrawn every 50 years or so ). So as the stars and such appear to rotate around the poles so does the Right Ascension part of the grid (but you can't see the grid, it's invisible). This coordinate system is used with telescopes that have an equatorial mounts. The following paragraph describes in general terms (I don't have one so its not exact) how this system is used with finding stars and stuff.
There should be away of getting the base of the mounting level. It may have a built in bubble or you might have to use your own hardware type. Your scope should also have a method for aligning the axis with the Celestial Pole (about 1degree from Polaris). Once you have your scope set up as accurately as you can, you then locate a prominate star in the sky that you can identify in the star charts. Put this star in the center of your eyepiece ( medium-high power should be accurate enough). Now if you have leveled and aligned properly with the Celestial Pole, your reading of Declination on the scope and the map should agree for that star. Now set your R.A. on your mount to match the maps coordinates for that star. You should verify your R.A. with a known star (or two), local to each region of sky you are going to explore. Once that is done all you have to do is look on the chart and find your chosen objects coordinates. move your telescope until the declination an right ascension match. Look through your telescope with low power....It should be right there.

Question submitted by Ian Head, age 27, London, England
and also submitted by Reed
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Eq. Wedge?

 An Eq. Wedge or Equatorial Wedge is a type of equatorial mount, mostly used for small Schmidt-Cassegrain type of telescopes. In its most simplest form an Eq. wedge consists of a platform that is attached to a base by a hinge on one edge. It also has a means to set an angle (that angle is determined by your latitude) between the base and platform.
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Note This is just a diagram of a wedge. A wedge will contain these components and more, but does not necessarily look like this.
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On the platform there is a disk that rotates and should have markings that are adjustable and correspond to the Right Ascension. This disk is what a telescope would be attached to. In setting up the wedge you point the axis of the disk toward the pole star and adjust the angle of the platform to match your latitude in degrees.
Eq Wedges that are sold, usually have additional features such as a clock drive that counters the Earths rotation and a means to mount the telescope.

Question submitted by Brady Blozvich, age 37, Grand Junction, Colorado
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Brightest stars name in Draco?

 The Brightest star in the constellation of Draco is named Eltanin. This star is in the head of Draco and is also designated as Gamma Draco. It is a Mag. 2.3 K type (Orange) star. What is unusual is that generaly the brightest star in a constellation is designated Alpha (Constellation name), but Alpha Draco, whos name is Thuban, is a mag. 3.7 A type (white). If my memory serves me right, Thuban was the Pole star about 2000 or so years ago.

(Question submitted by Sunnyside Elementary School Fifth grade, Stephen D. Shepperd Teacher, Kellogg, ID.
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Howdoya use star charts?

 Star Charts Take some getting use to. They are used best with a telescope that has a mount with RA and Dec settings (coordinate system). Then all you have to do (after your telescope is aligned on the north pole) is point your telescope so that the coordinates in your star chart for the object you want to look at are set that way on the scope. Now your scope should be pionted close to what you want to look at.
Now another way to use star charts is called star hopping. Make your self a circle on a small clear piece of plastic that is equal to the degrees your finder scope covers in the sky (Note that some star charts come with a plastic template so you don't have to make your own). Lets say that on your star charts a degree is .5 inch long and your finder scope, telerad, etc. covers 4 degrees (just as an example only), then you would make a circle 2 inches in diameter on a clear piece of plastic. This is now your template representating the field of view thru your finder.
Go to the object you want to find on the star charts (start with something bright and big like Andromda galaxy). Then find the closest star on the chart to your choice that you can also see in the night sky. Now with your plastic scale circle, figure how many circle widths, and which direction to your object. Note any stars that you might see in the finder scope along the way as land(sky)marks. Practice, practice, practice. As you get better start hunting for fainter and smaller objects. This method is what I use and it does work (there are no RA and Dec setting on my scope).
Question submitted by Mark Ervin

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Meteor?

 What is a (Whatsa) meteor? The solar system contains a large number of small solid particles (called meteoroids) in orbits around the sun. When one of these particles enters the Earth's atmosphere, the air resistance quickly heats the particle to incandescence. At the same time, the air along the particle trail is ionized. We see the combination of the incandescent particle and the ionized gas as a streak of light which we call a meteor.

A fireball is a meteor which is brighter than the brightest stars and planets. A fireball which explodes in flight is called a bolide. Most meteors start out as particles the size of a grain of sand and completely vaporize in a second or two.

Meteors are visible on any night of the year. At certain times of the year, the Earth encounters larger numbers of meteoroids all moving together along the same orbit. Such a group is known as a meteor stream and the visible phenomenon is called a meteor shower.

The color of a meteor depends on its speed and composition. They have been seen with tints of red, yellow, green, and blue. Bright meteors and fireballs may leave a train, or trail which may remain visible for many seconds after the bright flash of the meteor itself is gone. A clear moonless night is needed to see these trails.

Some meteor showers, such as the Quadrantids, Perseids, and Geminids are very regular in their return each year and do not vary greatly in the number of meteors seen at the time of maximum. Other showers, like the Leonids and Draconids are very unpredictable and may arrive in great numbers or not at all in any given year. Some showers such as the Aquarids and the Taurids are spread out over a fairly extended period of time without a sharp maximum. We know some showers have been around for many centuries. Chinese records of the Lyrids go back to 687 BC and back to 36 AD for the Perseids.

Lean back, relax, and enjoy the grandeur of the starry heavens and watch for those elusive flashes!

OBSERVING METEORS

You go outside at night and look up -- and see a bright streak of light. By the time you yell "LOOK!" it's gone. You watch carefully for another 15 minutes, but see no more flashes. Or maybe you're camping out under the stars. You look up and see a bright meteor, and then another, and another. Maybe one or two per minute until early dawn.

Is it possible to increase your chances of seeing these erratic heavenly visitors?

You can if you know the best times to look.

An observer located away from city lights on a clear and moonless night can expect to see an average of seven meteors per hour. The best time to watch for meteors is after midnight from the middle of summer to the end of autumn.

No special equipment is needed to observe meteors. However, to observe in comfort, you should have a lawn chair, a blanket or sleeping bag, and insect repellent. You also need a clear night preferably without a moon. Moon-light "drowns out" the light of all but the brightest meteors.

Answer from Gary Pittman.
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Blue Moon?

This is part mystery. The origional reason the moon was called blue has been lost in time and is unknown. Best guesses are that under special circumstanses, such as a volcanic explosion gasses and dust high in the atmosphere can cause the moon to look blue over a large part of the world. Smoke from forest fires have also been known to make the moon look blue, but only in a very local area.
Today the expression "a blue moon" is when there are two full moons in a month and the second full moon is known as a blue moon. There was one last night July 30. (I looked at it, but it did not look blue ;) )

Question submitted by James Gorman
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Planisphere?

Using a planisphere is a little different than using one of the magazines sky charts only because you have to set up a planisphere first.

Setting up the planisphere:

Look at the outer edge you will see months separated by the days of the months and you will see times of the night along side. Here all you do is match up the time of night you plan to view with the corresponding day of the month. This part goes with both planispheres and magazine charts. Now examine the chart/planisphere and notice that there is a point called the Zenith (planisphere will have the center of rotation brad at that point) this represents the point in the sky that is directly overhead.

Using the Planisphere (or one of the Magazine sky Charts):

Now lets say you are interested in what those bright stars are over to the South East. Hold your planisphere/chart in front of you and rotate The whole planisphere - don't loose your time and date settings) it so that South East (SE) is on the bottom. Now hold up the chart over head and match the bright stars and groupings to the south east with those on the chart. Star patterns (and Planet locations on charts) should be close enough to what you see on the chart to identify what constellations are there. This is where star charts for specific regions now come in.
Note: these charts are accurate at the latitude (+/- 10 degrees) for which they represent because they are intended to help you locate constellation size areas of the sky.

Lets try an example. (good for late October):

You want to find and see the Andromeda Galaxy M31 and maybe see M32 and M101 also. Your star chart shows you that the galaxy(ies) is located in the constellation of Andromeda in the northern part. You (being observant) also notice that Part of the "W" of Cassiopeia points toward one of the brighter stars of Andromeda and that the galaxy is close along that line about 3/4 of the way. But where is Andromeda and where is Cassiopeia with relation to tonight's sky, is it even up tonight when I'll be looking? So we get out our planisphere/magazine chart and set it up for tonight at 10PM. Then looking on the planisphere you find Andromeda and see that it is almost directly overhead a little to the east and your pointer (Cassiopeia) is to the north. You also notice that there is what is called the great Square of Pegasus close by. Going out side at 10PM tonight you pick a direction (Lets say North) and hold the planisphere/chart overhead with North on the chart facing north and look for your land mark star groupings (the "W" (pointer) and the great square). You should be able to find them with relative ease and can now put down the planisphere. Looking at the "W" and finding your pointer you follow an imaginary line to a brighter star (you are now in Andromeda) and then back up along the line so that you are looking 3/4 of the way to that star in Andromeda. This is where you will point your scope and start a gentle sweep. You will with a little patience find and see Andromeda Galaxy
Question submitted by David Shiel
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Please do not think I'm making fun anyone or being racist. I actually speak like this.  I also use words like... s'gedoutahere, s'go, Dij ya'seeit? and so on. I just enjoy messin up english and making  puns (my sons think they stink, but I like them) .


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