Search results
Results From The WOW.Com Content Network
Imaging of dim celestial targets, usually deep sky objects, requires exposure times of many minutes, particularly when narrowband images are being taken. In order for the resulting image to maintain usable clarity and sharpness during these exposures, the target must be held at the same position within the telescope's field of view during the whole exposure; any apparent motion would cause ...
Angular field of view is typically specified in degrees, while linear field of view is a ratio of lengths. For example, binoculars with a 5.8 degree (angular) field of view might be advertised as having a (linear) field of view of 102 mm per meter. As long as the FOV is less than about 10 degrees or so, the following approximation formulas ...
The finderscope usually has a much smaller magnification than the main telescope, thus providing a larger field of view, useful for manually pointing (a.k.a. "slewing") the main telescope into a roughly correct direction that can easily place a desired astronomical object in view when zooming in.
The eye relief of an optical instrument (such as a telescope, a microscope, or binoculars) is the distance from the last surface of an eyepiece within which the user's eye can obtain the full viewing angle. If a viewer's eye is outside this distance, a reduced field of view will be obtained.
NICMOS was installed on Hubble during its second servicing mission in 1997 along with the Space Telescope Imaging Spectrograph, replacing two earlier instruments.. NICMOS in turn has been largely superseded by the Wide Field Camera 3, which has a much larger field of view (135 by 127 arcsec, or 2.3 by 2.1 arcminutes), and reaches almost as far into the in
From the center to outer edge of the FGS field of view is 14.1 arcminutes [1] This is a diagram of the field of view of each Hubble Space Telescope instrument, including the three FGS instruments (FGS field of view(s) highlighted in yellow) A Fine Guidance Sensor being refurbished between servicing missions SM3A and SM4 A fine guidance sensors in space on STS Servicing Mission 2 in 1997
Then, the mount will move the telescope to that altitude and azimuth and track the object so it remains in the field of view despite Earth's rotation. Moving to the location is called slewing. The disconnected hand control of a GoTo telescope mount. The large arrow buttons are used for slewing the telescope.
An initial rough alignment is first performed using the polar scope. An image can then be captured and a star database is used to identify the exact field of view when aimed at stars near the pole - 'plate solving'. The telescope is then rotated ninety degrees around its right ascension axis and a new 'plate solve' is carried out.