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2011-01-20 Start-Up Gremlins (2011-01-20) Images from 2011-01-20 >>
Start-Up Gremlins Unusual start-up problems were encountered at beginning of session where double dot stars images and vertical streak trails where intermittently encountered. (see below) Switching off and restarting the ST10-XME camera seemed to fix the problem. (There has been no reoccurance of the problem in the followimg imaging sessions) |
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Example Image showing double dot / trail problem | ||
CCD Images (cropped, 150%
size) 5s exposure (single frame), 3x3 binning, C Filter, (#449002) 12" LX200R (at f/9.7) + ST-10XME |
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Problem Observations / Analysis | ||
- Vertical streaks (trail
lines) don't have the usual sharp digital character of blooming
streaks - Vertical lines are more like the trails one might get if the equatorially mounted telescope was still slewing/correcting or was jogging in Dec whilst recoding the image. However the sequence of frames (see below) makes this improbable. - Double dot feature appears for faint stars as well as bright stars - On brightest stars there is a faint 3rd and 4th dot (look closely at image below) - Brightness of trail line seems dependant on the brightness of the star - Star trails are roughly straight and or are not obviously curved - No double dot/star trail problem is noted with the V filter. - Is the problem related to Filter Wheel itself or the Camera's Control of the Filter Wheel ? |
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Sequence of frames | ||
1) Slewed to Lyr TZ Locate Frame, 5s, C, (#449001) Cloud? Target aborted. |
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2) Slewed to Cyg SS Initial Locate Frame 5s, C, (#449002) Double dot star
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3) Jogged 1 arc min West Final Locate Frame 5s, C, (#449003) Double dot star |
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4) Taking BVR Frames 15s, B, (#449004) No stars visible |
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4a) V Frame 5s, V, (#449005) Normal Image (No double dots or trail lines) |
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4b) B Frame 15s, B, (#449006) Cloud, with few stars |
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4c) B Frame 15s, B, (#449006) Cloud, with few stars |
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4d) R Frame 3s, R, (#449008) Double dot star |
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4e) B Frame 15s, B, (#449009) Double dot star |
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4f) V Frame 5s, V, (#449010) Normal image
(No double dot star
or trail line) |
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Following frames clouded out R, B (#449011-12). Target Imaging Aborted |
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5) Slewed to RX And, First Locate Frame First Locate Frame without visible stars (cloud ?) 5s, C, (#449013) |
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5b) Second Locate Frame 5s, C, (#449014) Double dot stars with trail lines on brightest stars. Secondary star dot is much weaker than primary star image. Aborted Target Imaging. |
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6) Restarted Camera. Took Image Slewed to Cyg SS 5s, C, (#449015) Normal Image From this image onwards |
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CCD Image (50% size) Single Frames, 3x3 binning, various filters (#449001 to #449015) |
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This Web Page: | Notes - Session 449 (2011-01-20) |
Last Updated : | 2015-05-15 |
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