BISHOP S UNIVERSITY ASTRONOMICAL OBSERVATORY

Transcription

1 BISHOP S UNIVERSITY ASTRONOMICAL OBSERVATORY PlaneWave CDK17 Equatorial Mount Telescope OPERATIONS MANUAL Jonathan St-Antoine August 2012

2 Introduction Bishop s University is proud to announce that its new Astronomical Observatory has already welcomed its 4000 th visitor. The Observatory was inaugurated in October 2006 and now houses a PlaneWave CDK17 Dall Kirkham Cassegrain German equatorial Mount telescope equipped with many instruments and cameras. One of the truly innovative features of this observatory is that the telescope can be remotely controlled from anywhere in the world. People who have internet access can point the telescope at planets, stars, and galaxies and see exactly what the telescope is observing in real time. The Observatory has been extensively used by students enrolled in astronomy classes offered by Bishop s University and Champlain College. Undergraduate Honours students have also been given a unique opportunity to carry out research using these instruments. But perhaps most importantly, the Observatory has allowed us to perform public outreach within our local community and to promote science. The Observatory has already hosted many K-12 school classes in addition to civic and cultural groups. We also schedule regular open houses for the general public and hold special events for members of the extended Bishop s family (employees, students, and community members). For more information about arranging a visit to the Bishop s University Astronomical Observatory, please contact us at (819) x2630 or come visit us at 2

3 Table of Contents -Safety Precautions Getting Started...7 The observatory The dome (old system) The telescope The software -Using the Telescope...16 Initializing the mount Manually operating the telescope -Ending the Session...21 Appendix Telescope Accessories...24 The Deck...26 The Dome (Remote Control System)...27 Telescope Specifications Calibrating the Telescope

4 Safety Precautions The deck 1) During a tour nobody is allowed on the deck without permission and proper supervision. 2) Children are not allowed on the deck without adult supervision and must be accounted for at all times. 3) Always stay on the deck's surface. Do not lean on the railings or go onto the roof! Failure to comply with these rules will lead to your immediate expulsion by Bishop's Security!!! The telescope 1) An authorized person must be present inside the dome whenever visitors are present. 2) Never point the telescope in the direction of the sun. 3) Always fully open the dome shutter before removing the telescope lens cap. 4) Always put the telescope lens caps back on before closing the dome shutters. 5) Never try to clean the telescope mirrors. 6) Only use compressed air to clean the eyepiece lenses. 4

5 The dome 1) Always close the trap door on the floor of the dome before operating the dome. Note that when the trap door is opened, always make sure it is safely latched by pulling on the door. 2) Never put fingers, or any objects into the orange electrical rail at the base of the dome. 3) In case of power failure when it is raining or snowing, immediately close the top shutter of the dome manually using the hand crank (Figure 1, 2 and 3). Fig.1 5

6 Fig.2 Fig.3 6

7 Getting started The observatory 1) Students who wish to make an appointment to use the telescope should contact either the Director of the observatory or the telescope operator. Observatory Director: Telsecope operator: Technical question: Observatory website: 2) Also, users should also check the Bishop s Observatory website Calendar schedule ( to look for any schedule conflicts. Rotating the dome (Manual system) 1) Find the observatory log book in N-401 and write down your name, date and the time you arrived. 2) Climb the stairs to the dome. The safe way to climb or descend the stairs is to face the stairs and use both hands on the rails. Turn on the lights at the top of the stairs (Figure 4). The switch on the left controls the red lights. Fig.4 7

8 3) Close the trap door on the floor before operating the telescope. 4) Open the dome shutters, the top shutter first, then the bottom shutter. The control switches are identified in Figure 5, and the control switch locks (on top of the switches) must be released to operate the switches. Fig.5 5) Connect the azimuth AC motor to the nearby electrical outlet (Figure 6). The red knob (Figure 7) controls the direction of rotation of the dome. NB. Keep the lens caps (covers) on the telescope while moving the dome, so as to prevent dust or debris from falling into the optics. Fig.6 8

9 Fig.7 The telescope 1) The telescope is mounted on a German equatorial mount. Electrical motors control Right Ascension and declination. Before using, turn on the three switches: power (red) switch, fan and focus (see Figures 16 and 17). 2) If the shroud is already strecthed around the struts of the telescope, slide it up so that it is near the top of the struts (as seen in Figure 8). Note that the shroud is a stretchy fabric that is used to protect the primary mirror from being touched by visitors. 3) Remove the plastic telescope cover (Figure 9), and mount the desired optical device (eyepiece, star diagonal, camera). 4) Remove the finder scope lens cap (cover). 9

10 Fig.8 Fig.9 10

11 The software Users who plan to operate the telescope are encouraged to download and become familiar with the open source software Stellarium (Figure 10 and 11). Although not part of the telescope control software, Stellarium is extremely useful to locate objects in the sky. It can show constellations, nebulae, clusters, planets, moons. Time and viewer s location can also be changed to enable the user to preview a planned observation. Details such as magnitude, position, name of objects are shown on screen. Fig.10 Fig.11 11

12 1) Turn on the computer. 2) Launch the folowing three programs in this order: STI, PWI and The Sky X. (Figure 12) Fig.12 12

13 STI is the driver interface for the telescope mount (see Figure 13), and if there is a startup malfunction the process can be aborted in STI. Some of the various possible commands are shown below. (A) To stop all process, (B) Mount tab, (C) Target tab, (D) Commands field, (E) Stop & start. Fig.13 13

14 PWI, (Plane Wave Interface) controls the focus of the telescope. Select COM6, in Figure 14 (A), and click connect. Use the arrows (see Figure 14 B) to control the focus. Fig.14 14

15 The Sky X is the main control interface of the telescope (Figure 15). To enhance the user s night vision capability, use the Window s 7 red colour setting. There is a shortcut on the desktop to do this. Fig.15 15

16 Using the telescope 1) Turn on the three switches: power (red) switch (Figure 16), and then the fan and focus (Figure 17). Fig.16 Fig.17 16

17 2) In the command field of STI (Figure 18) select unpark. The status field will display Tracking. Fig.18 3) In The Sky X, under telescope tab select start up and click on connect. The status field will display tracking at sidereal rate. 4) To point the telescope at an object you can do one of the following three things: i) In The sky X click on any object in the main window. Then, under Telescope tab click slew. ii) Under the find tab write the name of the object. Click center then, click slew. iii) Under the find tab you can choose an object by searching into one of the many library then, click center and slew. 17

18 5) If the telescope is not pointing at the right object or is not tracking well, you will need to reinitialize the mount. To reinitialize the mount follow steps 6 through 12. Initializing the mount 6) If the Sky X is open, then close it. 7) In STI select HOME in the command field. 8) In the new window click on Initializing using homing switch 9) Wait for both RA and DEC status field to display IDLE. 10) Then, click OK. 11) In STI click on START. 12) You can now reconnect the telescope in The Sky X. Manually operating the telescope 1) To manually move the telescope, use the arrows on the remote control shown in Figure 19. The speed can also be increased and decreased by pressing on the button at the center of the remote control. 18

19 Fig.19 2) The pier on which the telescope is installed can be raised and lowered using the controller shown in Figure 20. If you raise the pier, make sure to put it back at the lowest possible height before slewing the telescope to another object. Fig.20 19

20 3) The focus can be changed using the controller shown in Figure 21. Use only the arrows to do this. Fig.21 20

21 Ending a Session 1) Disconnect the telescope in The Sky X. Under the shut down tab, select disconnect. 2) Park the telescope before doing anything else. This procedure is similar to un-parking the telescope. In STI click on the mount tab, then, in the command field, choose park. 4) Once the telescope has stopped moving and the status field in STI displays PARKED, close STI and turn off the three switches that control the mount (red switch), the telescope and the fan (see Figures 16 and 17). 3) Shut down the remaining software and the computer. 4) Replace the primary mirror cap with extreme caution so that no debris falls onto the mirror. NB. There is no barrier between the cap and the mirror. 5) Put back the plastic protection for the secondary mirror. 6) Put back the protective (plastic) lens cap on the telescope eyepiece and on the finder scope. 7) Close the shutters of the dome. Start by closing the bottom shutter followed by the top one. Note: Extra care should be taken with the bottom shutter to see that it is has been closed properly before closing the top one. 21

22 8) Unplug the Remote control azimuth system if it was used (Figure 22). 9) When leaving N-401 make sure that the dome, the deck lights, and the doors are all properly closed (locked). 10) Write in the log book at what time you left the Observatory. 11) Return the key to the Director of the Observatory. 22

23 Appendix 23

24 Telescope accessories Eyepieces: An eyepiece is a type of lens that is attached to a variety of optical devices such as telescopes. The primary mirror of the telescope collects light and collimates it so that an eyepiece can focus it creating an image. The amount of magnification depends on the focal length of the eyepiece. The magnification is equal to 2939/f, where f is the focal length of the eyepiece in mm. Flip mirror system: A flip mirror system is an astrophotography device that allows the observer to see the target using the eyepiece before flipping the mirror and taking the photograph. Star diagonal: A star diagonal is an angled mirror or prism used in telescopes that allows viewing from a direction that is perpendicular to the optical tube axis. 24

25 Filters: An astronomical filter is a telescope accessory that is sometimes used to simply enhance the details in images of celestial objects. Filters can also be used on telescopes in order to understand the stellar classification (surface temperature) of a star. Barlow: The Barlow lens is a diverging lens which is used in series with other optics to magnify the image. Focal reducer: Reduces the telescope's focal length and magnification, usually by a fixed percentage, and widens the field of view. This may also assist with coma correction. 25

26 The deck Before going on deck, refer back to the Safety Precautions. 1) Turn on the observation deck lights. They are battery operated and used only as needed. 2) Unlock the door. 3) NB. At the end of a session shut off the deck LED lights (BATTERY OPERATED), and check that they are off. Then lock the door. 26

27 Rotating the dome (RC system) 1) The Remote Control system consists of the Azimuth AC motor, the manual control, the switch box and the relay box as shown in Figure 22. Fig.22 2) Connect the RC system as shown in Figure 23. 3) Rotate the dome using the azimuth momentary switch (Figure 24). 27

28 Fig.23 Fig.24 28

29 Telescope specifications The PlaneWave Instruments CDK17 is a 17 inch (0.43 m) f/6.8 Corrected Dall-Kirkham Astrograph telescope. The CDK17 has a dual carbon-fiber truss design, with 3 cooling fans ejecting air from the back of the telescope. The CDK24 covers a 52 mm field of view without any field curvature, off-axis coma, or astigmatism. The instrument weight is 94 lbs (43 kg) and comes standard with the large capacity 3.5" Hedrick focuser. System: Aperture: Focal Length: Focal Ratio: Central Obstruction: Back Focus from Mounting Surface: Back Focus from Racked in Focuser: Weight: OTA Length: Upper Cage: Lower Cage: Optical Performance: 17 inch (432 mm) 2939 mm ( inches) f/6.8 39% of the Primary Mirror Diameter 8.8 inch (224 mm) 5.8 inch (147 mm) 94 lbs (42.6 kg) 37 inch (940 mm) Carbon Fiber Truss Carbon Fiber Truss with Carbon Fiber Light Shroud 6.5 micron rms at 21mm and 9.6 micron at 26mm off-axis Primary mirror: Diameter: 17.5 inch (445 mm) Aperture: 17 inch (432 mm) Focal Ratio: f/2.6 Mounting: Laser Collimated and Permanently Fixed Material: Precision Annealed Pyrex Shape: Prolate Ellipsoid Coating: Enhanced Aluminum - 96% Secondary mirror: Diameter: 6.25 inch (159 mm) Material: Precision Annealed Pyrex Shape: Spherical Coating: Enhanced Aluminum - 96% Lens group: Diameter: 90 mm (3.54 inches) Number of lenses: 2 Coating: Broadband AR Coatings (less than.5% reflected from 400 to 700nm) 29

30 Calibrating the telescope 1) Open STI and in the command field select Home. Then, click on initialize using homing switch. 2) When both the RA axis and DEC axis status fields display IDLE click OK. 3) In STI click on START. 4) Then, in STI click the point XP button. 5) In the Point XP window select erase cal point and leave term. Click OK 6) Then, install the SBIG ST9XE camera on the telescope and then turn the On button on the camera s power supply. 7) In the command field in STI select RUN SCRIPT. 8) Then, MaxImDL will open and the script window should automatically open. If MaxIm DL doesn t open, then exit all software and repeat steps 1 through 7. 9) In the script window: 6 seconds should be chosen for the exposure time, 1 for the binning and 30 for the number of cal points. Then, in the script window click make point XP run. 10) In the script window click START. 11) During all the process the dome will need to be moved to follow the direction in which the telescope is pointing. 12) When the process is done, select in STI (under the command field) HOME. 13) In the new window click on find transition angle under the DEC column. Wait for the status to display idle then click find transition angle under the RA column. 14) Click OK. 15) Finally, set a new park position. In STI select set park position under the command field. Then, in the pop-up window select yes. 30