![I. Parallax](http://s1.studyres.com/store/data/005294111_1-2b2efe922eac314a905ce8b36cdbafe0-300x300.png)
galaxies
... What is a “star cluster”? • stars formed together at same time • stars may be gravitationally bound together • two types: open (galactic) and globular Image at http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/1 8/image/a/format/web/results/50/ ...
... What is a “star cluster”? • stars formed together at same time • stars may be gravitationally bound together • two types: open (galactic) and globular Image at http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/1 8/image/a/format/web/results/50/ ...
The Reflector - Peterborough Astronomical Association
... tripod and headed outside. There was a light rain falling at the time too, so I had to grab my umbrella as well. I took a nice shot for the clouds (top left – bronze metal) when I noticed some flashing to the south of me in the distance. It turns out there were lightning clouds due south of me over ...
... tripod and headed outside. There was a light rain falling at the time too, so I had to grab my umbrella as well. I took a nice shot for the clouds (top left – bronze metal) when I noticed some flashing to the south of me in the distance. It turns out there were lightning clouds due south of me over ...
PISGAH Text by Dr. Bob Hayward ASTRONOMICAL Astronomer
... of the bull, it is not actually a member of the Hyades cluster. Instead, it is what astronomers call a foreground star, one that lies in the same direction but which is closer to us. Realize that, while the celestial sphere over our heads at first glance appears to be a two-dimensional surface, it i ...
... of the bull, it is not actually a member of the Hyades cluster. Instead, it is what astronomers call a foreground star, one that lies in the same direction but which is closer to us. Realize that, while the celestial sphere over our heads at first glance appears to be a two-dimensional surface, it i ...
T Einstein’s Mirage Paul L. Schechter
... some directions and shrinking them in others. In the analogous case of terrestrial mirages, the deflections and distortions are due to thermal variations in the index of refraction of air. ...
... some directions and shrinking them in others. In the analogous case of terrestrial mirages, the deflections and distortions are due to thermal variations in the index of refraction of air. ...
Astrophotography
![](https://commons.wikimedia.org/wiki/Special:FilePath/Orion_Belt.jpg?width=300)
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.