... The first time you acquire an object you must include the overhead for the guide star acquisition. ... If it is larger, then the observer can choose to maintain pointing through the gyros (drop-to-gyro) or re-acquire the guide stars (3 minute overhead per re-acquisition-note that this is not the 6-minute orbit re-acquisition) every time the telescope goes back to the target; with the first option the pointing uncertainty is about 1 milliarcsec/second due to telescope drift. ... Exposure overheads: ....

... PISTON piston . ... this command is not used by the TCC The guide camera mechanical controller sets the filter, focus and other mechanical functions, but not the position of the guide camera in the focal plane. Positioning, if available, is handled by one or two guider position axes controllers , one per axis of motion. ... Notifies the controller that subsequent commands apply to the guider mechanical controller. ... Sets the piston of the guider to the specified value (in decimal microns). ...

An extra leap second has to be inserted at the end of 2008, so this is how you should count down on New Year's Eve to celebrate the start of the International Year of Astronomy according to Irish astronomers. The extra second is needed to bring the uniform measure of time used by physicists using atomic clocks back into nearly exact agreement with time as measured by the rotation of the Earth. ... There will be national and international events organized throughout the year to mark the occasion. ...

... Ranger 7 was designed to achieve a lunar impact trajectory and to transmit high-resolution photographs of the lunar surface during the final minutes of flight. ... Velocity at impact was 2.62 km/sec (1.62 miles per second). ... The television system consisted of a six slow-scan vidicon TV cameras capable of transmitting high-resolution, close-up television pictures of the lunar surface during the final minutes of flight before the spacecraft impacted the lunar surface. ...

... MY FIRST PUBLISHABLE DEEP SKY IMAGE!! Shot using my photography gear, Canon 5D mark ii, internal CLS filter, 7000K in camera white balance, 70-200mm f.2.8 lens + 1.4 extender, shot at 280mm focal length, ISO 1600, f/5.6, 50 seconds each x 114 images (95 minute total exposure). ... The only notable post processing was that I added 100% clarity to the stacked Nebulosity tiff image before doing my thing in Photoshop. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

STEP INTO THE BLUE - MEADE INSTRUMENTS PRODUCT GUIDE . ... Superb optical performance coupled with time proven computerized pointing and tracking has made the LX200 ACF series a best-seller in the high-performance telescope class. ... Meade's revolutionary LS LightSwitchтДв series of telescopes use advanced technologies to do what no other consumer telescopes have done before: take all the hassle out of using a telescope. ... Coronado Accessories . ... Meade Coronado Vixen-Style DoveTail (6" Length) . ...

Date: 2007-04-22 Time: 03:07:44 UT Object: M3 Instrument: Moore Observatory CDK20 Guiding: STV with 200 mm focal length wide field lens Camera: STL6303 Filter: R (RGB) Exposure: 300 seconds Processing: Dark subtraction and non-linear stretch Orientation: N up, W right Imagesize: 2048x3072 pixels Scale: 0.5375 seconds of arc or 0.0001493 degrees per pixel Field: 0.306x0.459 degree

... 2009 July 30 . 6 Minutes 42 Seconds . ... Explanation: The July 22nd total solar eclipse was the longest of the 21st century . From the point of maximum eclipse along the Moon's shadow track across the Pacific Ocean, the Moon completely blocked the Sun for a total of 6 minutes and 39 seconds. But from the deck of this cruise ship the duration of the total eclipse phase was extended to a whopping 6 minutes and 42 seconds by the ship's motion along the shadow track. ... About APOD | ...