A Nova is one event that happens repeatedly in the universe. This phenomena happens when a star comes to an end. As the light and heat capacity of stars wear throughout the years, it suddenly becomes pale white, thus getting the name “white dwarf”, due to the shrinking and dimming light power of the star. As time passes by, it then explodes, causing the star to burn out its remaining energy and become brighter than it ever was.

One example of this is the Supernova of 1054. This happened in China, when astronomers saw a star so bright that it was seen during the day. And since this occurrence was quite astonishing and odd, this event was recorded.

Books also say that a Nova is the smaller version of a supernova, since an event like this happens with a pair of stars, one which is a white dwarf and that of a cooler star. Since materials are being sucked off by the white dwarf, this causes the explosion of the star, though it may not be totally obliterated.

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A telescope is an instrument used to observe objects from afar. The word is derived from Greek words tele and skopein which means “far” and “to see” respectively. Contrary to popular belief, it was not ‘invented' by Galileo. There has been evidence of a refracting telescope that has been in use in the Netherlands during 1608 and its development was credited to spectacle makers Hans Lippershey and Zacharias Janssen, and a third person Jacob Metius. However, it was Galileo who improved on the devices soon after so they can be used for exploring the heavens.

A telescope works by collecting electromagnetic radiation, which on earth-speak means visible light. However, with the development of space technology, there has risen the capability to utilize the full range of the electromagnetic spectrum and use the radio band. The first radio telescope was used in 1937 and there have been subsequent development of telescopes that can work with other wavelengths such as gamma rays.

Photo by: Mike Peel Creative Commons

A telescope has A telescope has three major capabilities – the ability to magnify, the ability to resolve images and create sharp images and the most important being the ability to collect light so it ‘sees' better (which is also the reason why your pupils enlarge when the room is dark or when it's nighttime). The part of a telescope which collects light is the ‘objective'. The objective of a refractor telescope is a glass lens and a reflector telescope uses a (surprise, surprise) mirror.

The first telescopes used to observe the heavens where refractor telescopes and they were subject to problems of chromic aberration or color distortion and spherical aberration among others. It wasn't until 1668 that the first practical reflecting telescope was developed by no other than Sir Isaac Newton with the idea that parabolic mirrors can reduce aberration and more than a hundred years after, achromatic lenses where developed and the rest, as they say, is history.

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A nebula or a “newborn star” appears like a cloud of gas and dust. More accurately, a nebula cloud is actually the birthplace of not just one but many stars. Nebulae (the plural of nebula) are mostly made up of hydrogen and other gases, and these determine the nebula’s appearance and, consequently, its classification or kind. There are emission nebulae, reflection nebulae, and even dark nebulae, to mention a few types.

The next phase in a star's life cycle is as a “regular” star––the kind seen normally in the nighttime skies, and of which the sun in our solar system is a good example. Our own sun is comparable to a teen-age star.

Millions of years later, a normal star will become a red giant, and then a red dwarf, and finally a white dwarf or a neutron star. A neutron star is much smaller than it used to be, like a drastically shrunken version of the original, but it is still very hot. The average neutron star is just about 1% the size of our sun, or as big as the earth, but its temperature can be something like 8,000 degrees Celsius. It is also much less bright than a regular star. Eventually, a neutron star cools and then fades. The whole process of a star’s “death” takes billions of years.

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The word “nebula” comes from Latin which means “cloud.” It is apt, because nebulae (the plural of nebula) look like clouds of gases. Nebulae are made up mostly of hydrogen and helium gases, plus plasma and dust. These clouds are believed to be the birthplace of stars.

There are many kinds of nebulae, often determined by the gases that make them up and how they appear to observers on earth. One type is the diffuse nebula, which has no definite shape and no definite outlines. Another type is the emission nebula, made up of plasma or ionized gas, and emitting multi-colored lights. An example of an emission nebula is the Eagle nebula. Yet another type is a planetary nebula, such as the Cat's Eye Nebula. This is thought to be composed of the shells of “dying” stars called white dwarves.

A very fascinating type of nebula is the dark nebula, an example of which is the Horsehead Nebula. This kind of nebula is extremely dense, with very thick clouds that block out the light behind them and stars in the background. Aside from those mentioned, some famous nebulae are the Crab Nebula or M-1, M-57 which is a Ring Nebula, the Cygnus Loop, and the Orion Nebula. These are fascinating objects in the sky that can be watched through a telescope.

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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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What are meteor storms?

Meteor storms are intense meteor showers. They may seem to radiate from just one point in the sky because the particles travel parallel to each other. Most meteor storms and showers are named after the constellation where they are nearest.

There are two particular meteor showers a stargazer should take note of:

The first would be the Perseids. It is the most regular and most visible of all the showers and is associated with a specific comet (the comet Swift-Tuttle). They peak between August 9 and 14 of every year and is said to have been observed approximately for the past 2000 years. The pre-dawn hours would be the best time to see them.

The second would be the Leonids and is claimed to be the most spectacular meteor shower. Connected with another comet (the comet Tempel-Tuttle), the meteors appear to radiate from one point – where the constellation Leo is. They say that the Leonid showers turn into a storm approximately every 33 years. But recent storm activity belies that theory as the last Leonid meteor storms were recorded in recent years: one storm in 1999 and two each for the years 2001 and 2002.

A meteor storm occurs unexpectedly. So should you be packing your bags for a meteor watching outside the city, be alert and scan the sky from time to time so that you won’t miss it.

Leonid Meteor Storm

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Neutrons are found at the center or nucleus of an atom. They are electrically neutral, which means they don’t have either a positive or a negative charge. It is believed that if a proton (which is positively charged) and an electron (which is negatively charged) are smashed together, the result would be a charge-less particle that is a neutron. Apart from smashing these particles, neutrons are hard to observe. Because they have no charge means that they do not react to electromagnetic forces, unlike protons and electrons. They therefore cannot be observed using electromagnetic manipulation.

Experiments on sub-atomic particles in a laboratory, like smashing them up, can be really costly and complicated. A cheaper but effective alternative that allows scientists to study neutrons is to look at the stars and examine their behavior. It has been found that a specific celestial body called a neutron star consists mostly of neutrons. A neutron star is produced from an explosion of a supernova, where protons and electrons are smashed together and combined to become neutrons. Neutron stars are incredibly dense because their whole mass is packed within a very little space. They are believed to be at the end stage of a star’s life cycle.

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After this, a main sequence star will continue emitting light and heat energy until it consumes all of its limited supply of hydrogen in its core. Then it will become redder, larger and luminous as it becomes a red giant star. At this stage, its outer envelopes will collapse and expand consuming nearby objects like planets, meteors and other heavenly objects.

It will continue to collapse its outer envelope and will even intensity its hotness is it exhausts the helium in its core, becoming a red super giant. It will eventually lose all of its mass and will leave a remnant of a hot core of carbon within a nebula of expelled gas. In some instances, the radiation from this hot core ionizes a nebula to produce a planetary nebula. But in most cases, the core of carbon cools down to become a white dwarf, a star that is relatively dim as compared to what it once was, a bright star and this ends its stellar evolution until it becomes black dwarf or a burned out star.

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The Sun’s photosphere extends near its surface, in the region where the gas becomes opaque, with an optical depth of up to 400 kilometers. Despite the light emitted, the photosphere is one of the coolest regions in the Sun’s atmosphere with a temperature of about 6000 K. This region is also the densest part of the solar atmosphere but still incomparable to Earth’s atmosphere. At a closer look, the photosphere is comprised of convection cells known as granules, which are gas cells with a diameter of about 1000 kilometers with a life span of about eight minutes, following a continuous boiling pattern. This region in the solar atmosphere often appears as dark specks called sunspots, which is caused by the Sun’s magnetic field.

Other astronomical bodies have a photosphere like the Sun. This region in an astronomical body’s atmosphere is often the deepest, which is transparent for photons in different wavelength of the electromagnetic spectrum. The photosphere is a visual description of the Sun’s or another star’s surface.

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These illuminated reticles are actually needed to accurately align telescopes. It also has a grid of patterns placed in the eyepiece of an optical instrument and is also used to establish a scale or position. A reticle control would allow manual rotation of the reticle for use when it comes to lunar surface alignments. Crossing by the line on the star image defines a plane containing the star. Crossing of the other line defines another plane containing the same star or a different one.

The intersection of these planes forms a line that defines a direction of the star. To define the internal orientation of the particular star being viewed, sightings on at least two stars are required. Each star sighting requires the same procedure. Multiple reticle crossings and their corresponding marks can be made on either or both stars to improve the accuracy of the sightings. Upon completion of the second star sighting, the guide computer would then calculate its orientation with respect to a predefined reference coordinate system.

Centering stars without a reticle would be very difficult. It would be best to select the best reticle for your telescope to make sure that finding the stars and centering it would be easier.

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