Frequently Asked Questions

Frequently Asked Questions

The local MicroObservatory horizons are available here, and common questions are listed below.

Problem

Probable Cause

Possible Solution

Stars/planets look like fuzzy donuts in the main camera…

The telescope is out of focus. Although the telescope is focused within the first few days of being installed, something may have changed which caused a focus jump.

The default focus needs to be redone by the MO staff. In the meantime, focus values can be manually selected when an image request is made. Experiment to find the best value. Email us at the address below (assuming there isn't already a note about it on the 'take image' page).

There are long streaks of light going off at an angle from stars in the image, all the way to the edge of the chip; or perhaps a 'ghosting' double image.

If the streaks are white (not gray) and are mostly up/down, then it is saturation. Otherwise, the shutter may be sticking open during chip readout, causing a streak as the chip is read-out row-by-row.

If saturation, reduce exposure time. If gray streaking at an angle, try to take image again or use a different telescope.

There are short streaks of light going off to the right from bright stars.

Chip readout/timing problem.

This is a known problem which will require a re-programming of certain electronic chips in the telescope.

There are lots of small dots all over the image. Are they stars?

They are NOT stars, but rather 'hot' pixels, or possibly cosmic rays.

This is an inherent result in using any CCD. You can try to subtract the hot pixels using a uniform gray 'flat' frame (such as one taken when there were heavy clouds) and/or a 'dark' frame taken using the opaque filter.

The image is all black with many single white pixels. It was a clear night, other images from around that time of night (and similar exposure time) turned out.

If you eliminated the possibility of a too-short exposure, didn't use the ND4 (gray) filter, and know it was 100% clear, then likely the shutter may have been stuck closed.

Try to take image again (it often will work on another attempt) or use a different telescope. Email us at the address below (assuming there isn't already a note about it on the 'take image' page).

The image is all black (and has no single white pixels).

Probably, the image was totally saturated (the shutter time was too long).

Reduce the exposure time.

I requested an image, I saw it in the queue, but now it's no longer there and there's no image in the 'get image' page.

Removed from queue or networking problem.

If the telescope has had some recent testing/work done on it, we may have postponed or deleted that telescope's queue. If the network or mail server goes down, the image will not be transferred and the image will be lost. We plan to implement a contingency transfer at a later time.

My image has been in the queue, but was never taken.

Telescope taken off-line during the time the image was to have been taken.

We occasionally take the telescopes off-line to adjust pointing, focus, etc, but don't delete the current queue. The images in the queue will be taken the next time the telescope is on-line at the requested time. Sometimes when there is bad weather we may take the telescope off-line manually.

When should I use zoom in or zoom out in the main camera?

Zooming in is done in software, so it doesn't actually add any more information. It would be better to always use 'zoom out' and do the adjustment in an image processing program. If you don't have this available, you may want to choose 'zoom in' to see a smaller object bigger.

The stars are slightly streaked left to right.

Tracking turned off (very long streaks), or telescope not perfectly aligned

The MO support team needs to adjust the alignment of the telescope.

In using the Australia telescope, my image is all black (with a few hot pixels). It was clear and the telescope settings were correct.

The telescope is located in a shed with a roll-off roof. In bad weather or during the day, the roof is rolled closed, and may not have been opened back up when your image was taken. Also, the horizon is blocked by the shed, especially towards the north. In some cases, the altitude for a clear shot is as much as 35 degrees.

Wait for the star to be higher in the sky (more than 35 degrees), and retake the image. Also, Mt. Stromlo frequently has low fog which will degrade the quality of the images.

Telescope Status

Telescope

Comments

General Notes

Annie

Off-line. In Cambridge, repairs underway. Unknown when scheduled to return to service.

Ben

Off-line. In Hawaii, with elevation motion problem. Scheduled to be repaired and return on-line by mid-Febraury.

Cecilia

In Cambridge, on-line (blue-sensitive chip!).

Donald

Off-line but repaired. In transit to Arizona, scheduled to be on-line by mid-February .

Ed

Off-line. Main ccd imager malfunction and failed. In transit to Cambridge. Unknown when scheduled to return to service.

last updated January 25, 2002.

If you experience other technical problems, please email microobservatorysupport@cfa.harvard.edu.

*Problem*	*Probable Cause*	*Possible Solution*
Stars/planets look like fuzzy donuts in the main camera…	The telescope is out of focus. Although the telescope is focused within the first few days of being installed, something may have changed which caused a focus jump.	The default focus needs to be redone by the MO staff. In the meantime, focus values can be manually selected when an image request is made. Experiment to find the best value. Email us at the address below (assuming there isn't already a note about it on the 'take image' page).
There are long streaks of light going off at an angle from stars in the image, all the way to the edge of the chip; or perhaps a 'ghosting' double image.	If the streaks are white (not gray) and are mostly up/down, then it is saturation. Otherwise, the shutter may be sticking open during chip readout, causing a streak as the chip is read-out row-by-row.	If saturation, reduce exposure time. If gray streaking at an angle, try to take image again or use a different telescope.
There are short streaks of light going off to the right from bright stars.	Chip readout/timing problem.	This is a known problem which will require a re-programming of certain electronic chips in the telescope.
There are lots of small dots all over the image. Are they stars?	They are NOT stars, but rather 'hot' pixels, or possibly cosmic rays.	This is an inherent result in using any CCD. You can try to subtract the hot pixels using a uniform gray 'flat' frame (such as one taken when there were heavy clouds) and/or a 'dark' frame taken using the opaque filter.
The image is all black with many single white pixels. It was a clear night, other images from around that time of night (and similar exposure time) turned out.	If you eliminated the possibility of a too-short exposure, didn't use the ND4 (gray) filter, and know it was 100% clear, then likely the shutter may have been stuck closed.	Try to take image again (it often will work on another attempt) or use a different telescope. Email us at the address below (assuming there isn't already a note about it on the 'take image' page).
The image is all black (and has no single white pixels).	Probably, the image was totally saturated (the shutter time was too long).	Reduce the exposure time.
I requested an image, I saw it in the queue, but now it's no longer there and there's no image in the 'get image' page.	Removed from queue or networking problem.	If the telescope has had some recent testing/work done on it, we may have postponed or deleted that telescope's queue. If the network or mail server goes down, the image will not be transferred and the image will be lost. We plan to implement a contingency transfer at a later time.
My image has been in the queue, but was never taken.	Telescope taken off-line during the time the image was to have been taken.	We occasionally take the telescopes off-line to adjust pointing, focus, etc, but don't delete the current queue. The images in the queue will be taken the next time the telescope is on-line at the requested time. Sometimes when there is bad weather we may take the telescope off-line manually.
When should I use zoom in or zoom out in the main camera?		Zooming in is done in software, so it doesn't actually add any more information. It would be better to always use 'zoom out' and do the adjustment in an image processing program. If you don't have this available, you may want to choose 'zoom in' to see a smaller object bigger.
The stars are slightly streaked left to right.	Tracking turned off (very long streaks), or telescope not perfectly aligned	The MO support team needs to adjust the alignment of the telescope.
In using the Australia telescope, my image is all black (with a few hot pixels). It was clear and the telescope settings were correct.	The telescope is located in a shed with a roll-off roof. In bad weather or during the day, the roof is rolled closed, and may not have been opened back up when your image was taken. Also, the horizon is blocked by the shed, especially towards the north. In some cases, the altitude for a clear shot is as much as 35 degrees.	Wait for the star to be higher in the sky (more than 35 degrees), and retake the image. Also, Mt. Stromlo frequently has low fog which will degrade the quality of the images.

*Telescope Status*
*Telescope*	*Comments*
General Notes
Annie	Off-line. In Cambridge, repairs underway. Unknown when scheduled to return to service.
Ben	Off-line. In Hawaii, with elevation motion problem. Scheduled to be repaired and return on-line by mid-Febraury.
Cecilia	In Cambridge, on-line (blue-sensitive chip!).
Donald	Off-line but repaired. In transit to Arizona, scheduled to be on-line by mid-February .
Ed	Off-line. Main ccd imager malfunction and failed. In transit to Cambridge. Unknown when scheduled to return to service.