THE LIFE CYCLES OF STARS (3)
... The ancient Babylonians 1800 BC put together the first star catalogues. The Greek Hipparchus (180-125 BC) and later Claudius Ptolemy in Alexandria about 150 AD classified stars according to their apparent brightness to the eye, dividing them six into classes of brightness. The brightest stars were c ...
... The ancient Babylonians 1800 BC put together the first star catalogues. The Greek Hipparchus (180-125 BC) and later Claudius Ptolemy in Alexandria about 150 AD classified stars according to their apparent brightness to the eye, dividing them six into classes of brightness. The brightest stars were c ...
Publisher: Emily Barrosse Acquisitions Editor: Kelley Tyner
... he more massive a star is, the shorter its stay on the main sequence. The most massive stars may be there for only a few million years. A star like the Sun, on the other hand, is not especially massive and will live on the main sequence for about ten billion years. Since it has taken over four billi ...
... he more massive a star is, the shorter its stay on the main sequence. The most massive stars may be there for only a few million years. A star like the Sun, on the other hand, is not especially massive and will live on the main sequence for about ten billion years. Since it has taken over four billi ...
The Sun and Stars
... three regions apparent surface that we can see from a distance is called the photosphere, which means “sphere of light.” Just above it is the chromosphere. This is a very hot layer of plasma, a high-energy state of matter. The corona is the outermost layer of the sun’s atmosphere, extending millions ...
... three regions apparent surface that we can see from a distance is called the photosphere, which means “sphere of light.” Just above it is the chromosphere. This is a very hot layer of plasma, a high-energy state of matter. The corona is the outermost layer of the sun’s atmosphere, extending millions ...
Astrometry of Asteroids
... In this exercise you will be using images of the sky to find asteroids and measure their positions. Asteroids are small rocky objects that orbit the sun just like planets. They are located predominately between the orbit of Mars and Jupiter, about 2.8 Astronomical Units from the sun. Asteroids do or ...
... In this exercise you will be using images of the sky to find asteroids and measure their positions. Asteroids are small rocky objects that orbit the sun just like planets. They are located predominately between the orbit of Mars and Jupiter, about 2.8 Astronomical Units from the sun. Asteroids do or ...
Astrometry of Asteroids
... In this exercise you will be using images of the sky to find asteroids and measure their positions. Asteroids are small rocky objects that orbit the sun just like planets. They are located predominately between the orbit of Mars and Jupiter, about 2.8 Astronomical Units from the sun. Asteroids do or ...
... In this exercise you will be using images of the sky to find asteroids and measure their positions. Asteroids are small rocky objects that orbit the sun just like planets. They are located predominately between the orbit of Mars and Jupiter, about 2.8 Astronomical Units from the sun. Asteroids do or ...
Galaxies (and stars) in the far infrared: results from the AKARI All
... With IRAS four bands (12, 25, 60, 100 μm), a very detailed classification was possible. However, in the case of AKARI FIS ASS, we must rely only on four FIR bands (at longer wavelengths), and this cannot be a trivial application of IRAS methodology, since the physical processes behind emission in th ...
... With IRAS four bands (12, 25, 60, 100 μm), a very detailed classification was possible. However, in the case of AKARI FIS ASS, we must rely only on four FIR bands (at longer wavelengths), and this cannot be a trivial application of IRAS methodology, since the physical processes behind emission in th ...
A Practical Guide to Exoplanet Observing
... This is a step-by-step guide to exoplanet observing that is intended for both the newcomer to exoplanet observing, as well as for the more-experienced exoplanet observer. For the former, it is desirable that the user have some experience in deep sky or variable star imaging. The more experienced exo ...
... This is a step-by-step guide to exoplanet observing that is intended for both the newcomer to exoplanet observing, as well as for the more-experienced exoplanet observer. For the former, it is desirable that the user have some experience in deep sky or variable star imaging. The more experienced exo ...
S T A R S
... star clusters, nebulae and galaxies.) Omega Centauri was named as a fourth magnitude star almost 2000 years ago. In 1677 Halley observed it as a cluster and not as a star. Now there are known to be over a million stars in the cluster with some 1000 times more bright than our sun. The cluster is abou ...
... star clusters, nebulae and galaxies.) Omega Centauri was named as a fourth magnitude star almost 2000 years ago. In 1677 Halley observed it as a cluster and not as a star. Now there are known to be over a million stars in the cluster with some 1000 times more bright than our sun. The cluster is abou ...
Astrophotography
Astrophotography is a specialized type of photography for recording images of astronomical objects and large areas of the night sky. The first photograph of an astronomical object (the Moon) was taken in 1840, but it was not until the late 19th century that advances in technology allowed for detailed stellar photography. Besides being able to record the details of extended objects such as the Moon, Sun, and planets, astrophotography has the ability to image objects invisible to the human eye such as dim stars, nebulae, and galaxies. This is done by long time exposure since both film and digital cameras can accumulate and sum light photons over these long periods of time. Photography revolutionized the field of professional astronomical research, with long time exposures recording hundreds of thousands of new stars and nebulae that were invisible to the human eye, leading to specialized and ever larger optical telescopes that were essentially big cameras designed to collect light to be recorded on film. Direct astrophotography had an early role in sky surveys and star classification but over time it has given way to more sophisticated equipment and techniques designed for specific fields of scientific research, with film (and later astronomical CCD cameras) becoming just one of many forms of sensor.Astrophotography is a large sub-discipline in amateur astronomy where it is usually used to record aesthetically pleasing images, rather than for scientific research, with a whole range of equipment and techniques dedicated to the activity.