Project 3. Colour in Astronomy
... Another reason why you obtain lower temperatures is that the Interstellar space is not a perfect vacuum. The interstellar medium (ISM) comprises cold neutral gas (H I at ≈ 70 K), warm neutral gas (H I at 6,000 K) and hot ionised plasma (H II at 106 K) primarily located in the plane of the galaxy ...
... Another reason why you obtain lower temperatures is that the Interstellar space is not a perfect vacuum. The interstellar medium (ISM) comprises cold neutral gas (H I at ≈ 70 K), warm neutral gas (H I at 6,000 K) and hot ionised plasma (H II at 106 K) primarily located in the plane of the galaxy ...
The Project Gutenberg EBook of History of Astronomy, by George
... of the different ages, to give due credit even to the ancients. No one can expect, in a history of astronomy of limited size, to find a treatise on “practical” or on “theoretical astronomy,” nor a complete “descriptive astronomy,” and still less a book on “speculative astronomy.” Something of each o ...
... of the different ages, to give due credit even to the ancients. No one can expect, in a history of astronomy of limited size, to find a treatise on “practical” or on “theoretical astronomy,” nor a complete “descriptive astronomy,” and still less a book on “speculative astronomy.” Something of each o ...
Exploring the Universe
... – What we see is called the apparent magnitude – Absolute magnitude is a measurement of the brightness as if the distance from the earth was 32.6 light years away. A uniform distance, so it’s the real brightness. – Besides the sun, the brightest star is Sirius ...
... – What we see is called the apparent magnitude – Absolute magnitude is a measurement of the brightness as if the distance from the earth was 32.6 light years away. A uniform distance, so it’s the real brightness. – Besides the sun, the brightest star is Sirius ...
Ursa Major, the Great Bear
... make up the front part and its legs. For one to make out the shape of the bear really needs some imagination. The Big Dipper can be used as a beginner guide in the night sky: The two outer edge stars that make up the “bowl” of the dipper – Merak (β) and Dubhe (α) – are pointer stars to Polaris, the ...
... make up the front part and its legs. For one to make out the shape of the bear really needs some imagination. The Big Dipper can be used as a beginner guide in the night sky: The two outer edge stars that make up the “bowl” of the dipper – Merak (β) and Dubhe (α) – are pointer stars to Polaris, the ...
design for the TMT mid-infrared adaptive optics system
... optical relay and deformable mirror. The conventional optical relay is used without sacrificing the thermal background by using multiple off-axis laser guide stars to avoid a warm dichroic in the common path. Three laser guide stars, equally spaced 75” off axis, and a “conventional” 30x30 deformable ...
... optical relay and deformable mirror. The conventional optical relay is used without sacrificing the thermal background by using multiple off-axis laser guide stars to avoid a warm dichroic in the common path. Three laser guide stars, equally spaced 75” off axis, and a “conventional” 30x30 deformable ...
star pattern identification : application to the precise attitude
... thus the attitude determination went inaccurate in the region of scientific interest. All these problems which were left aside in a first intensive attitude production were recently reassessed and the present status of their solution is described in this work. Of particular interest was the possibil ...
... thus the attitude determination went inaccurate in the region of scientific interest. All these problems which were left aside in a first intensive attitude production were recently reassessed and the present status of their solution is described in this work. Of particular interest was the possibil ...
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.