The lunar month is used by different cultures around the world. In the Middle East, people mark the beginning of this month when a young crescent moon appears after a close pairing of a celestial body with the Sun occurs or maybe about one or a couple of days before. Egyptians determine the beginning of this month when the Moon is no longer visible before sunrise.

A lunar month is equivalent to a synodic month with an approximate length of 29 days, 12 hours, 44 minutes and 3 seconds. There other ways of interpreting this particular month.

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It is generally known as zero degrees longitude or vertical line of reference in the world map. It was established through scientific intervention and conventions. Throughout time, the prime meridian has taken different places and exact locations. The established and modern prime meridian is now based in the royal observatory in Greenwich, a part of the legal territories of England, in the year 1884.

The modern and current zero degrees meridian, which is based on the Royal Observatory, in Greenwich, is the common referent point in navigation, either by air, or sea. It was chosen as the official prime meridian through the means of an international convention through the efforts of the then United States President Chester Arthur, with the help of 25 delegates from various nations. At those times, over two-thirds of the world has made Greenwich as the point of reference for the prime meridian. It was only the nation of France who abstained and did not vote for the said convention’s beliefs. Since then, France still used Paris as the point of navigation for more decades.

As additional information, the Royal Observatory, where the prime meridian is based on, was established by a certain Sir George Airy in the year 1851. It is now converted as a museum and at night, it beams a light northward through a laser, to mark the prime meridian.

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The planck scale is the smallest unit of measurement recognized by physical theory. Physicists use this scale to measure the smallest sizes or the shortest lengths of time that can exist. Named after Max Planck, who is the founder of quantum theory, this scale has given many physicists a way to envision space and time in smaller proportions—or, more specifically, in grainy proportions. This idea is the complete opposite of the relativity theory which believes space to be a continuous stretch of un-grainy matter.

Physicists currently cannot prove what really happens at the planck scale. And this is because in psychics, the smaller something is, the bigger the amount of energy is required to study it. This is because as the energy of a photon (quantum of electromagnetic energy) increases, so does its size measured in wavelengths decreases. This means, the smaller the granule, the hotter is its energy.

The energy required to study space granularity is known as the planck energy, which is believed to be about a quintillion (1 followed by 30 zeros) times larger than the energies currently conceivable by any particle accelerators in the world. Although experimental evidence to back-up the planck scale dynamics is hard to come by, measuring instruments like the WMAP probe has led physicists to believe that there could actually be a time when our universe achieved planck scale energies.

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When drafting visual binary orbits, the line that indicates the north celestial pole (NCP) is usually drawn downward, placing north at the bottom of the draft. The PA can then be measured by going counterclockwise from this point to any number in a range of 0 to 359 degrees.

A position angle can also refer to the proper motion angle. This is the observable movement of a star on the celestial sphere perpendicular to an observer’s line of sight. This component of spatial motion of a celestial body is measure in seconds of arc per year and is dependent on the actual relative movements of both the sun and the star. It refers to transverse motion only and has nothing to do with motion that goes toward or away from the sun. The naked eye can see an average of 0.1” of proper motion of stars per annum.

The term position angle is also extended and applied to other astronomical objects like comets and galaxies. Used in this manner, the term position angle may refer to the angle formed by the major axis of a particular object in relation to its north celestial pole (NCP) line.

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Parallax provides astronomers with a simple method of calculating the distance of many celestial objects. As the Earth revolves around the Sun, celestial objects seem to be located at different positions when observed month after month. When a star is observed during June and December, observers can make use of two different viewpoints or lines of sight to the star to measure the distance. These two lines of sight intersect at the star being observed, forming an angle and half of this angle is the parallax. Typically, the distance is measured in parsecs by getting the inverse of the observed parallax measured in arc seconds.

There are different kinds of parallax, namely, stellar, solar, lunar, diurnal, and dynamic or moving cluster. It is important to keep in mind that parallax decreases with distance and can only be used to measure celestial objects at a maximum distance of 100 parsecs. The use of this concept in astronomy is extended with much precision through the use of the Hipparcos satellite.

Geometric Technique – Parallax

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Visualize the Earth as a see through sphere. Looking through the Earth one may observe an equatorial plane, with a middle point, or center of the sphere or Earth. In order to indicate the Latitude of any point on the top of the Earth, you can draw a line from the center of the sphere to the point of interest.

Thus, the angle of the point with respect to the equator is the Latitude. North of the equator, the latitude is positive, south of the equator, the latitude is negative. Thus, it is because of this angle, along with the longitude, that reading the map has become easier and more effective to use.

No longer are the days in which maps would roughly present distances based on mere perception, and not clear measurement. With the Longitude and Latitude, one will be able to specifically pinpoint with only slight error a certain point on Earth. This has been a helpful yet innovative tool over the years.

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One light-year is equivalent to approximately less than ten trillion kilometers. In technical definition, the International Astronomical Union (IAU) defined a light-year as the distance travelled by light in a vacuum using the Julian calendar as the reference for time. The Julian year is not similar to the Gregorian year we are used to and the IAU published the constants that accompany these. The unit of light-year is the official galactic scale, though some publications and astrometry still prefer the use of parsec.

The use of light-years can also be simplified by using the prefixes kilo-, mega- and giga- to signify very large distance values. This unit of measurement represents the distance between the observer and the celestial body or between one celestial bodies to another celestial body located in the same star system.

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Light-gathering power is a way to measure the performance and effectiveness of a telescope that is proportionate to the square root of the size of the aperture. For instance, a telescope that possesses more than two times its diameter has the potential to collect about four times as many light.

The principle is that the more light that the telescope gathers, the more complicated images it can resolve. The telescope may make the complex and vague looking objects appear much clearer. When choosing the right type of telescope, you have to take a look at its Light-gathering power, and see whether or not the power is enough for your needs. If you want to look merely at the stars in the sky, a not very complex telescope with an average Light-gathering power may be all right.

However, if you are more interested in taking a look at the more complex and tiny and vague objects in space that are pretty much invisible to the naked eye, on could opt for a telescope with a much higher Light-gathering power. This could make very vague objects in space turn out very clear. Space observatories make use mostly of very high Light-gathering power telescopes, to be able to study the likes of far away planets and stars.

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When people go outside, especially at night, and try looking for the Polaris constellation, it is noticeable that the stars near this star formation revolve in an east to west direction, as to which, the northern star does not move in any manner, as time passes by during evening.

To make it short, the Northern Celestial Pole is a certain direction relating to our planet’s North Pole Projection. It has a 90 degree declination, or the distance near the celestial poles of the earth, in which case is the North and South Poles.

Also, this celestial point is vital since the sun, which is defined as a star, revolves around this particular point. Although our planet is close to the sun, the tilting of the Earth has little variation compared to the sun’s rotational axis, and is slightly away from our planet’s north celestial pole.

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The limiting magnitude of a celestial object is greatly obscured by the presence of light pollution and sky glow in the observer’s location. These factors greatly reduce the limiting magnitude of the celestial body being observed and some of the faintest stars that comprise a constellation in the sky might not be visible. The limiting magnitude can also be used to refer to the detection of very faint stars using the naked eye near the zenith or the point directly above the observer during a moonless night sky. This brightness indicator can be used to determine the overall brightness of the sky and quantify the amount of light pollution.

Observers and amateur astronomers can make use of tables that have published values of limiting magnitude of celestial objects. If a telescope is to be used, calculating this particular value may be more convenient.

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