Koehler Urban Astrophotography

Goal: Capture Mars near the Oct. 13, 2020 date of closest approach (Opposition). Left tripod vibration pads in the lawn from the Mars imaging session on the 15/16th. In the early afternoon of the 17th, brought the tripod back out & set back on vibration pads in the lawn.  Mount was found to be level... no need to re-level (time & effort saved) by keeping the pads in the lawn.   Installed counterweights & the Celestron CN-10.  Rebalanced the mount... determined a working arrangement of counter weights ... and worked out optics configuration  for the CN-10 with the Zwo ASI120MC-S as the primary imaging camera with and without the 3X Barlow.   Was not able to use the M60 -> T-thread adapter with the eyepiece projection cell to the Zwo and reach infinity focus.  Instead, used the 2" eyepiece adapter -> 1.25" eyepiece adapter -> Zwo (with eyepiece adapter installed) for prime focus and inserted the Celestron X-Cel LX 3x Barlow (with eyepiece holder) into the o

Goal: Capture Mars near the Oct. 13, 2020 date of closest approach (Opposition). Reconfigured the Meade LX10 EMC SCT for planetary imaging.  Exchanged the 0.63 focal reducer for a 3x Celestron X-Cel LX Barlow.  The optical train was assembled (staring at the SCT threads) with the Celestron T-mount adapter connected to eyepiece projection cell (with Barlow lens inside sans its eyepiece holder) to the T-mount to the Zwo ASI120MC-S.  No filters. In the late afternoon, started by setting up the Celestron CGEM DX with a rough north-oriented alignment, mounting the OTA (initially sans guider scope) and using ASI capture software on the cell phone, began working to focus the overall system with the Zwo ASI-120MC-S on distant trees.   And the nextdoor streetlight --where the field of view barely contained the base of the bulb. With evening  darkness, aligned the mount with the polar scope and worked to focus to a star.  No luck was found trying to use the ASI capture software on the cell phone

9:33 -- Unprecedented fifth session on a target... third night in a row with clear skies.  Yesterday started out with clouds, but cleared by midnight. Tonight is clear right from the start.  Mounted the telescope & plugged everything back in and started an additional session on IC 1805. 9:52 -- Noted issues plate solving where an offset appeared consistently with the mount failing to reach IC 1805 repeatedly.  Attempted slewing to a different target near the meridian, no luck.  Launched PHD2 to determine if polar alignment was lost.  Drift alignment was initially squirrelly with RA moving all over ... but DEC relatively stable with PHD2 drift alignment reporting 2.69' (not bad) in AZ ... but 23' in elevation.  Telescope mount sank a bit in the grass?  Adjusted elevation twice with PHD2 to arrive at 3.8'. 10:16 -- After adjusting elevation on the mount to obtain reasonable polar alignment, restarted the IC 1805 sequence with the scheduler.  This time plate solving center

Goal: dust to dawn imaging for IC 1805.   Started with the mount already in the yard using the same alignment from 10/6.  Re-mounted the ST80 telescope & started Indi @ 9pm (with IC 1805 still a bit too low).  Guiding RMS in the internal guider in Indi after 9 minutes of guiding: 2" (and dropping to 1.3). 9:39pm:  With significant clouds, guiding frequently interrupted... but restarts as the sky clears.   12:08am: With 44 images collected so far in this session, copied #44 over to examine in Picasa for focus & exposure.  Focus: good.  Exposure -- noted the capture was at ISO100 (used for flats collected on 10/3).  Updated to ISO 1600 and restarted the job.  New darks will have to be collected for 180s at ISO100.   7:48am:  81 lights captured in total through 4:23am. Job ran to completion with mount parked at the completion time of 4:45am.

Heart Nebula, Day 3 Goal: Additional session on IC 1805 to improve noise from 10/2 & 10/3 images. Started at 09:30 surveying a different spot in the front yard where the mount may not need to be moved since it's possible for a couple clear nights in a row.  Leveled mount and started drift alignment with PHD2 (centered on a bright star close to the meridian & equator) on the HP Proliant 17 laptop... but experienced issues calibrating... but no clear error messages. Calibration seemed to end without producing a valid result.  Moved downstairs and started ~10:45pm.  Found calibration problematic here as well (star did not move enough)... but noted the guide camera focal length was incorrect (168 vs 50mm).  Fixed and calibration went smoothly.  With both PHD2 clients, the Zwo ASI-120mc-s did not expose 2s frames normally -- instead PHD2 complained and moved the camera to streaming mode. Initial results in AZ show polar alignment error of 5.99' (drifting up). Tightened left.

Day two of collection for IC 1805.  Scope set up started at ~9:25 and completed leveling and initial polar alignment with polar scope at 9:50. Watched Legends of Kora. Very distracting. Started KStars / Indi at 10:25pm and slewed to equator / meridian.  Launched PHD2 and started a drift alignment.  Between large deviations in Dec (wierd), appeared to be no significant azimuth polar alignment error.  Slewed on the equator as far west as prudent and examined altitude. This appeared to settle at ~2'. Unloaded PHD2 and switched to internal guider in Indi.  Created a new schedule in Indi & started the job.  Slewed & performed plate solving w/o issue. Began guiding (defaulted to 3 second integration as used last evening). Internal guider required 2 minutes to calibrate before being to autoguide at 10:46pm.  Total RMS after 2 minutes: 0.84". Copied over the first capture. Paused job. Checked for exposure (ok at 180s) and focus in Picasa.  Unhappy with focus. Checked on the ca

Goal -- The Heart Nebula, IC 1805 Setup:  Orion ST80, Cosmicar 50mm, dual-narrow band filter, Astrodon clear EOS filter, CGEM DX, Odroid XU4, Canon T3I (astro modded) @ ISO1600 with day light white balance.  Set up in front yard. Huge nearly full moon... very clear skies with bright stars. Setup: 7:30-8.  Initial polar alignment through polar scope as noted in Polar Alignment android app. Polar alignment: Started on the venerable HP Pavilion 17 (new SSD) with Fedora 32. PHD2 drift alignment... Verified guide scope focal length == 50mm in PHD2 (critical first step). Value was correct (pre-configured from Indy?) Started by performing fresh calibration... telephone pole in the way... failed a number of times. Gave up & restored calibration & ran Guide Assistant.  GA showed initial polar alignment of 5.4 arc min (measured over 246s and 44 frames (sample count). Drift alignement... Az: 1) Dec trending down... tightened left while watching through polar scope.  Looks far worse at 62.