Maine Skies Astronomy   ---- Equipment

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PLR ObservatoryThe telescope is mounted on a concrete pier inside of a roll-off roof observatory in my back yard.    Observatory equipment consists of a variety of components that allow both visual observing and imaging of night sky objects.     The primary parts are: the Astro-Physics Starfire 152 telescope,   the mount to hold and point the scope is a Losmandy G11 German Equatorial Mount, which is supported by a concrete pier for excellent stability.    A variety of Nagler eyepieces are used in the telescope's eyepiece holder for higher or lower magnification.  Also the SBIG ST2000XM ccd camera can be mounted in place of an eyepiece to take exposures of night objects.     A few other parts help out such as the RoboFocus, a computer controlled focuser which allows for very precise control of the focus.   Kendrick dew heaters that wrap around the telescope's objective lens keep it just a little warmer than the surrounding air and prevents dew from forming on the critical optical part.    Of course, no amateur observatory would be without a computer to tie it all together and allow remote control of it all.     

Astro-Physics Telescope in Observatory The Astro-Physics StarFire 152 telescope is the heart of the whole system.   Although this scope is new to me, it is 15 years old, the previous owners kept it in outstanding condition (thanks Rick!).   I am on the waiting list with AP for a new one, but the wait is at least 4 or 5 years!
Astro-Physics is world renowned for making optics that are second to none, and overall quality that is just as outstanding.   It is literally the one to which others are compared.   I have owned 5 telescopes and viewed through many others; this one absolutely outdoes them all in it's ability to make stars look like pinpoints, make detail on planets and the moon stand out incredibly, and shows awesome depth and clarity on Nebulas and Galaxies. Technical specifications for the scope:  6 inch (152 mm) f/9 Apochromat  Magnesium fluoride coated objective lens,  with 96.5% light transmission;AP in operation 1300 mm focal length and about 5 feet in overall length, the weight is 20 lbs.    It gathers 460 times as much light as the unaided human eye.

This photo with my ugly mug in the background was taken at about 1am while imaging a spiral galaxy near the big dipper.

AP with Guide ScopeThe addition of a second camera and telescope complete the setup of a guide scope.   A 70mm (2.7 inch dia) TeleVue Pronto telescope and an SBIG ST5C camera are used to autoguide the telescope's mount.    The guide scope watches the position of a single star and if the star 'moves' then the telescope mount is given a correction to its position, putting the guide star back in the correct spot.   Autoguiding allows for very long imaging times with the primary telescope and camera.     The first successful image using this setup was 50 minutes in duration and shows a nice image of M1, the Crab Nebula.

Guide ScopeThis image shows the guide scope up close.  The Pronto is held in place by two rings with 3 long thumb screw in each ring.  This allows the guide scope to be aligned to point in the exact same location as the primary scope.   It is a sturdy mounting method that allows for adjustment and at the same time eliminates any possible flexture between the two telescopes.    Lack of flexture is critical in autoguiding accuracy. 

Losmandy G11 Equitorial MountThe Losmandy G11 Equatorial mount provides very stable and accurately controlled pointing of the telescope.   It uses a Gemini controller which connects the azimuth and declination motors, a hand held controller, connects to the CCD autoguider and to the PC.  The Gemini has a built-in database of about 41,000 objects and is capable of a variety of methods to improve the pointing and tracking accuracy of the mount.   It is capable of supporting a payload of up to 60 lbs.   

SBIG CCD CameraThe CCD camera is made by SBIG and is the ST2000XM model.   It attaches to the telescope via a nosepiece that fits into the telescope's eyepiece holder.  The camera has a black & white 1600 x 1200 CCD chip for imaging and a smaller second chip for autoguiding.   The st2k has a built-in refrigeration system to cool the imaging chip.  The colder the chip is the better the signal-to-noise ratio is, which means a cleaner picture.   In order to take a color image, the camera has to take a picture with a red filter in place, then green, then blue.  The built-in color filter wheel provides color filters and a hydrogen alpha filter.   The RGB set is combined into a color image.    Beyond RGB color images, luminance images are used to show more detail, then the RGBs are added to color the image. 

The camera can take a picture as quick as 0.01 second or expose for as long as an hour or anywhere in between.    Very bright objects like the moon or a bright planet get a short image time usually about .01 second for the moon and .03 to .05 second for jupiter or mars.   Distant and dim objects like galaxies, clusters and ST2000XM back side and connectionsnebula require a longer exposure time and generally, the longer the image time the more detail appears in it.    This view of the back side shows where the cooling fan and optional water cooling system connectors are.  Also the connectors can be seen that hook the camera up to the PC, telescope mount and power.   

One of the camera's best features is the second ccd chip used for autoguiding.    Over time, a star or object being imaged may drift.  The slightest drift off course shows up in an image that make stars look like eggs or worse worms.    The autoguider watches a single star repeatedly taking an image of it.  If the star moves offset from it's initial position, the camera  tells the telescope how to move it back in position.  This process happens continuously while the main ccd chip is exposing an image.     Using the autoguider, very long exposure times can be reached.    I have imaged for as long as 30 minutes in a single shot with perfectly round stars.   A typical unguided image is one minute or less.

RoboFocusThe RoboFocus is a motorizes the telescope's focuser and is controlled by either a hand held controller or the PC.  It was an enormous help in achieving both a repeatable sharp focus, and doing so way more quickly than by hand.  It can move the focuser knob with far more granular movements than the human hand can, and it remembers where the sharpest setting is for any eyepiece or camera setup.    This addition went on my old telescope and then upgraded it to fit on the StarFire's focuser.    The CCDSoft program that is used on the PC to expose images on the camera has a function called @focus that will move the focuser around and take pictures and figure out where the sharpest focus and leave the telescope there.

Gemini controllerThe Gemini control module for the Losmandy G11 mount is shown here along with the Kendrick dew controller.  The Gemini is the heart of the control system for pointing the telescope.    It has a variety of features that enable very accurate control.  For example, although it knows approximately where things in the sky are, any inaccuracy in polar alignment will result in the same inaccuracy in finding objects.   The Gemini can build a model the pointing characteristics of the mount.  This is done by centering 6 or more stars (one at a time)  in the eyepiece and telling Gemini  that it's now centered on each one.  The more stars that are added to the pointing model, the more accurate the mount becomes with told to slew to a particular object.    I have found that after 4 or 5 alignment stars are added to the model, it always nails subsequent objects dead center when told to slew to them.

RoboFocus and Gemini hand held controllersThe hand held controllers shown here are the RoboFocus on the left and the Gemini on the right.    Both are velcro'd to the base plate for easy access and storage in the dark.

LX-200 Telescope The previous telescope was an Meade LX-200 10" Schmidt-Cassegrain.    I used it for about 3 years and learned a lot about astronomy, telescopes and imaging with it.   It's 10 inch arpeture gathered enough light to be able to visualy see magnitude 13 galaxies and pluto at mag 13.8!

Action Photo! Dan looks through the LX-200 on New Year's Eve 2001.   It was a balmy 10 below zero that night, somewhat warmer than it would be later in the season.    The sky was sharp as we looked at Jupiter, Saturn and a variety of  galaxies and clusters.