There are a few possibilities. It might sound obvious, but check the end of the scope for a lens cap. We don't normally use them but they exist. Next, look to see if there is a condensate on the lens. Shining a light indirectly at the lens should reveal this. If the star is very badly focused AND the aperture is fogged up, it might not show up. Most likely, however, someone touched the finder scope, misaligning it. If you are that person, shame on you. Regardless, it is a tricky process to get everything aligned again. See a TA for help. If none are around, here is the basic procedure:
You need to find a bright star in the eyepiece. It's tough to do, but sight down the scope and align as best you can by eye. Use the biggest size lens you can find, to increase your field of view. When that is centered, make sure the RA and Dec knobs are locked. Loosen and tighten the thumb screws around the finder scope until the star is also in the center of the finder scope. If you can't see the crosshairs on the finder, have someone hold a light at an angle such that it illuminates the crosshairs without overshadowing the star. It is not as easy as it sounds. Good luck.
First, does CCDsoft detect the camera? Check the "status" bar at the bottom of the main CCDsoft menu. If it says that it is connected, then refer above. If it is not connected, check the power to the CCD camera. One of the cameras seems to lose its power connection sometimes. Slewing can spur this, as the wire is torqued slightly. Check all the other connections as well. There should be a wire running from the camera to the computer, and one running from the scope to the computer. Make sure they're plugged in.
There are a few likely explanations. First, how long was the slew? Though these scopes are precisely mounted, slews across a long stretch of sky can cause the star to be slightly out of the CCD image. Try going back (you should be able to get back to the place where you came from) and then slewing to an intermediate destination, between the source object and the object that you are slewing to. Once on the intermediate object, re-center, re-sync (see procedure sections 5b and the Bonus Direction for instructions on how to do this) and then complete the slew.
Another likely explanation is that the telescope is not stably mounted. The screws on the back of the scope must be tightened completely; any breathing room leads to slight misalignments. Tighten the screws to be sure they're not loose.
The telescopes are also aligned so that they work on specific piers. While the effects of putting a scope on the wrong pier are not documented, it is possible that they could lead to slight alignment problems. Check the documentation in the observatory to see which scope goes where and try again.
Finally, check to make sure that the power cord is still plugged in. The torque from a slew could have wrenched it out of place.
I hate focusing.
Yeah, focusing is a pain. Here are a few tips:
1- Backlash might be a problem. When you change from focusing in to focusing out (or vice versa) the autofocuser does not transition smoothly. A large number of focus units (around 500) are required to change direction, before any new focusing in that direction is attempted. Take that into account when you focus. See the procedure section 7c for details.
2- Check to see if there is ice on the lens. That tends to make focusing nearly impossible. Luckily, a hair dryer works to remove the ice. Talk to a TA or instructor about doing this.
3- Relax. Seriously. Go get a drink of water. Come back and try again in 2 minutes. It's a hard task, trying to force it makes it harder.
4- Give the camera time to update. After each focus step, pause for 5-10 seconds to allow the changes to be reflected by the new downloaded image. You might focus right past ideal by taking too long.
5- Try changing the background and range. See the procedure for more details.
There are two things to try, both of which will decrease download speed. First, change the bin size in the CCD options menu to 3x3 instead of 1x1. This step is documented in the instructions. Also, you can change the size of the area that you are looking at. Select "subframe" and enclose a region surrounding the object that you are looking at. Be sure not to make it too small, as you will become disoriented looking at it too close up. Both of these methods decrease the amount of units of data needed to be processed, thus speeding up the download time.
I can't move
This is an unfortunate, though documented problem. CCDsoft does not have control over the movement of the telescope. In order to move, you must use "The Sky"'s slewing tool. The "Bonus Directions" in the procedure describes how to do this.
Yeah, I don't know. Colors are nice, but meaningless for most of what we use these cameras for. A CCD camera only sees a count of the number of incident photons. In order to gain any information on colors of objects, you must change the filter and see if there is any difference in incident light due to filtering.
Find the Needle in the Haystack
First, read 8b in the procedure. It is possible that you have the telescope set too sensitively. When set at this level of sensitivity, the image you see does not discern between high levels of incident light and lower levels. Both show up as white on the screen. You can fix this by following the directions in the procedure.
Ask your instructor or TA for specific naming conventions for files. The astronomy 101/102 students should save their files as *.st7 type, as the programs we use to process them expect that file type.
The following links are virtual breadcrumbs marking the 12 most recent pages you have visited in Bucknell.edu. If you want to remember a specific page forever click the pin in the top right corner and we will be sure not to replace it. Close this message.