Photometry is often carried out using photometers. Photometers have been used since the early days of astronomy and most astronomers build specialized photometers for specific telescopes. The simplest method of doing photometry is by utilizing an astronomical telescope and specialized optical filters. Once the radiation is received through the telescope, it passes through the optical filters and a photosensitive instrument captures and records the intensity. Measuring the light in the near infrared to the ultraviolet spectrum typically requires the use of photoelectric photometers and today, CCD cameras are slowly replacing these photometers. CCD cameras can take multiple shots of a particular celestial object in study and later on processed to extract the intensity values based on the snapshots.

Photometry despite the simplicity of the concept is a very complicated study of celestial objects based in the light they emit. But the light provides astronomers with many hints on the orbital periods of binary stars, a small planet’s rotating period and the strength of a supernova based on the energy released.

The post Photometry appeared first on Planet Facts.

Newtonian telescope is a kind of reflecting telescope that has a concave primary mirror and a flat secondary mirror. It is patterned after the telescope invented by Sir Isaac Newton, the famous British astronomer and scientist who during the 17th century. Sir Newton first invented this kind of telescope in 1668. His telescope had a simple yet functional design. Today, the Newtonian telescope is still very popular; it is not very hard to make, and therefore not as expensive as other, more sophisticated kinds of telescope.

In Newton’s time, there were already telescopes in use, but they were refracting ones, not the reflecting kind. They were not very effective because, due to the principle of refraction, they caused colors and images to become distorted. This phenomenon is called chromatic aberration, and Newton thought it could be eliminated if a telescope employed the principles of reflection instead of refraction. And so, using his knowledge of optics, mirrors and the color spectrum, and drawing upon earlier ideas put forth by scientists like Galileo Galilei and Giovanni Francesco Sagredo, Newton was able to produce the first reflecting telescope.

The first Newtonian telescope did not use any lens. Instead, it used mirrors that were shaped and ground to form an optical surface. It was revolutionary in that it used a secondary mirror that was diagonally mounted to reflect the image from the primary mirror at a precise ninety-degree angle. Because of this, the reflection had minimal obstruction and no chromatic aberration.

The telescope was a success. It could see as far as the moons of Jupiter. The invention earned Newton his admittance into the elite Royal Society of London.

Newtonian Telescope

The post Newtonian Telescope appeared first on Planet Facts.

Photo by: Liftarn Creative Commons

Location is important when putting together your own star party. You would need a secluded spot away from bright city lights in order to maximize your viewing. You will also need to consider a place where there is relatively low rainfall so that clouds do not obscure your view of the stars. Alternately, you can choose a specific time for your star party so that you know that the sky remains clear.

If you do not have the resources to organize your own star party, you can check regional or national events where you can participate to hone your own astronomical skills or just share some time with other hobbyists or professional astronomers. You would just need to find out other details like registration fees, board and lodging, transport costs and the likes so that your star party will be a memorable one.

With your enthusiasm coupled with others who share your same passion, your hobby will become more meaningful and the sight of the stars on a clear night will not just be yours to cherish.

The post Star Party appeared first on Planet Facts.

Photo by: Jmencisom Creative Commons

A Wolf-Rayet (WR) star has a temperature of 25,000 to 50,000 K. It has a very thick atmosphere that is almost the size of a star. Annually, a WR star loses mass quickly and as this happens, a very strong wind envelopes the area because of the radiation pressure inside its atmosphere. This kind of star is immensely huge and is usually 20 times larger than the Earth’s sun. Typically, a WR star is almost at the end of its lifetime.

The cause of its heavy wind is due to carbon and oxygen nearing its surface and basking in its powerful light. Its wind is so dense and thick that it hides the star itself from vicinity. In the Milky Way, there are almost 300 WR stars identified.

The wind carries with it mass the size of Earth every year. Because of the lost mass, it eventually lessens the life span of a star. It is said that really huge stars turn into WR stars as their stellar lives come to an end and later on they burst into a supernova. Scientists claim that it is also possible for a WR star to become a black hole when they collapse.

The post Wolf Rayet Star appeared first on Planet Facts.

Photo by: Brews ohare Creative Commons

A standard candle is a class of astronomical objects that belong to the same class and have a standard luminosity or brightness. You can actually determine an object’s distance from the earth using standard candles.

This is a technical process which involves comparing the object’s brightness against a known or measured brightness from objects that belong to the same class. For example, you spot a certain object like a star or supernova, and determine that it is a standard candle; you can get its distance by measuring its brightness and comparing it to the known brightness of objects that are similar to it.

This method of determining the distance of an astronomical object is just one of the ways to measure distances in outer space. Other methods can also be used such as the parallax method or the astronomical unit.

The main drawback of using standard candles is the relative measure employed in determining the brightness of the celestial object. For example, you will have to know the exact magnitude of the brightness of each and every member of that class well enough to say that you have an accurate measure of its distance. You would also need to make sure that the absolute magnitude of your standard candle has been measured properly in order to use the formula in determining the distance of the object you have observed.

Nevertheless, with proper training and careful observation, you can very well utilize this method to determine the distance of the object you saw one night under a clear, starry, sky.

The post Standard Candle appeared first on Planet Facts.

Another novel use of spectroscopy in astronomy is the determination of a star’s composition. By breaking down a star’s light into its spectra, scientists are able to find out what it is made up of. Breaking down light into its spectrum is actually revealing the energy of its constituent components. By knowing the intensity of a particular wavelength in the spectrum, the astronomer can deduce what makes up a star.

There are certain drawbacks to spectroscopy though. In order to be effective, the light source should be fairly strong enough to break it down into its spectrum. This means that you would need to study very bright stars or have very powerful telescopes in order to magnify the faint light source from the sky.

The post Spectroscopy appeared first on Planet Facts.

One common problem often encountered by potential astronomers is the limited field of view offered by binoculars or telescopes. This means that you can scour the sky and not locate the star you are looking for because of the limits set by your viewing instrument. You can remedy this by pointing it to the appropriate spot in the sky, guided by star hopping.

You can start star hopping by following constellations that are easy to spot and using them as guides. For example, Orion’s belt on the constellation Orion, points to the star Sirius to its left. Following the big dipper points you to North Star is another example of star hopping.

You may also utilize other tools such as star atlases so that you won’t lose your way as you poke your eyepiece into the different parts of the nighttime sky. Do bear in mind that star atlases would be highly dependent on your location. A person in the United States would see a totally different sky from one who is in Australia.

With a little bit of luck and lots of experience, you will be able to navigate through the night sky with ease, using star hopping as a jumping point to a more meaningful astronomical experience.

The post Star Hopping appeared first on Planet Facts.