1. Maxim DL
2. TheSkyX Pro
Software Bisque - TheSkyX Professional
TheSkyX Professional, by Software Bisque, is a"planetarium" program TheSkyX is used to
enables finding and identifying objects in the sky, it can zoom in & out from the entire sky to tiny
areas of the sky, It can connect to a telescope mount and control it - for example, pointing the
scope at a specific object, using a third party software like Maxim DL or by itself. Using a
solve plate the accuracy of pointing is primarily based on the accuracy of knowing the scope's
position (geographically) and current time, as well as the capability of the mount
(plus any corrective pointing software, such as Pinpoint)- plate solving. Clicking on
any object in TheSkyX a small box will appear with information (left bottom - image below)
that provides information on the object, including its position (both equatorially,
and in alt-az coordinates); the rise, transit and set of the object; the object brightness and
size; a picture of most objects; and much additional information.
TheSkyX can download current data of celestial objects like asteroids, comets, and
man-made satellites, and can even track low earth orbit ("LEO") satellites..
The image below shows a typical set-up of TheSkyX (this happens to be in the daytime, as
the sun is in the image). At the far upper right is a small window that controls the observatory
dome - enabling tracking of the dome slit with the telescope, as it follows the astronomical
object through the sky (i.e., counteracting the rotation of the earth, so that the object appears
"still" to the camera, allowing a long time exposure).
The small reddish object in the center of the image above is the field of view ("FOV") indicator. When the image is zoomed in, the FOV indicator enables seeing what the telescope and camera will see - i.e., how big the field will be, where the object will be centered, AND - very importantly for a long focal-length (i.e., high magnification) telescope: the angle of the guide chip, relative to the main chip, and relative to the stars. When imaging a very small field (at 3200mm focal length, and with my camera chip size, my total imaging field is only 15 arcminutes (i.e., 0.25 degree) square; if it is desired to use adaptive opitcs to control the scope, a relatively bright star is required, and most small areas of the sky don't happen to have a bright enough star. The brighter the star, the faster the AO can operate (up to about 30 times per second) - which allows partial correction for disturbances in the atmosphere (which is what makes stars "twinkle"). Therefore, one must center the object AND rotate the camera so that a suitable guide star is centered on the guide chip, as shown on the image below.
Note here that in order to place the very bright star in the center of the guide chip, it was necessary to offset the globular cluster on the main imaging chip. I could have selected a much dimmer star which allowed exact centering of the object on the main chip, but then the AO would have run slower, allowing less correction during a long imaging run. In "olden days" (about 5 years ago, prior to amateurs having adaptive optics), scopes were corrected during exposures using a guide camera, but only making corrections once every few seconds. Today, using AO, corrections are made in a fraction of a second. Therefore, the guide star exposure must be significantly reduced, thus requiring rather bright guide stars - typically in the 6-9 magnitude range. While the AO will work with magnitude 10-12 stars, the correction rate would be much slower - for example, once per second, rather than 10 times per second. This will correct for errors in the mount, but will not be fast enough to correct disturbances in the atmosphere. [the disturbances in the atmosphere in the column of air along the optical axis of the scope moves across the diameter of the scope quickly, depending on the amount of wind, so corrections for this must be of the same timescale as the changing atmospheric conditions]
TheSkyX can also set-up mosaic images (to capture a wider section of the sky with high resolution). Above is a mosaic set-up for the Andromeda galaxy, with each frame being the field of view ("FOV") of the Starlight Xpress 694 camera and 12" AG scope. In this case, 60 images must be taken to capture the entire galaxy. There is a small overlap between the images, so that they can be accurately combined.
MaximDL, written by Doug George, and sold by Cyanogen, is used primarily for controlling the astronomical camera - i.e., for doing the actual picture-taking. It can also be used for post-processing of images prior to insertion into Photoshop. MaximDL connects to the telescope, and can also control the telescope directly, although TheSky is mainly used for this purpose (however, it is very convenient to use MaximDL to nudge the scope around, center the image, and even go to specific objects). Connection to the telescope allows MaximDL to know where the image is being taken, so can add that information to the FITS header of the image. The newer version of MaximDL (V.5) can also control the observatory dome. It could actually be used to control the entire system (camera, scope, and dome), although I still use TheSkyX to control the scope and dome.
MaximDL also has provisions for measuring the image - for example, stellar diameters ("FWHM" - full width half maximum). If calibrated properly, it can also measure stellar magnitudes fairly accurately. It has the ability to do photometry (for example, plot the intensity variations of variable stars, or even transits of planets across stars!). MaximDL also has built-in Pinpoint capability (see the "Pinpoint" page), allowing it to "plate solve" and determine the center of the image very precisely, as well as determine the "position angle" (sometimes called "North angle") of the image, which calibrates the rotator.
The following image shows MaximDL in action. The camera window (far top right) controls the camera - set-up, exposures, and inspection of images). The AO control allows set-up and operation of an adaptive optics accessory (see "AO"), which can keep stars centered to within a fraction of a pixel (= a fraction of an arcsecond!). Below the AO window is the Screen Stretch control, which enables setting the dynamic range of the image to actually be able to see objects (rather than all black, which is the normal starting point of most astronomical images). The Information window provides data on specific objects (pixels) in the image, including star size and magnitude, average background noise in the image, etc. The Image window (far left) shows the actual image (in this case, the Dumbell Nebula) taken by the main camera. The smaller window (to the left of the AO Control window) shows the image from the guide chip (you can see the guide star at the bottom of the image). Finally, there are two windows from other programs overlaid on MaximDL - the FocusMax window, which enables automatic focusing of the image; and the Status window of CCD Autopilot, which is controlling the entire system autonomously. This image shows my normal MaximDL windows set-up.