All images shot with ToUCam Proc SC1.5 webcam
Reference URL for Webcam camera modifications:
http://home.clara.net/smunch/wintro.htm
Scope is LX200 10inch F10 run at F3 with Meade F3.3 FR
NOTE: All pictures were shot with NO GUIDING, just PEC and PRAY.
Images captured in Astrovideo (and it's powerfull scripting capabilites)
http://www.ip.pt/coaa/astrovideo.htm
Register and proceesed in IRIS and Picture Publisher for JPG'ing
Christian Buil great program IRIS:
http://www.astrosurf.com/buil/us/iris/iris.htm
Images from Aug 6, 2002
Each frame is 3x60seconds
Captured with Astrovideo scripting
15 dark+flats median averaged
'full_pr' processing in IRIS
Mosaic in PictPub
10:36EDT to 11:36EDT
M57 photometry data
Dataset used is done by Arne Henden available here
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/m57.dat
Image taken 7/10/2002
Please note: this is very preliminary and does not account for
stated magnitude errors in Mr Henden's dataset.
I loaded it into Excel:
-Threw out all stars brighter than mag 14.83
-then picked only B-V from .791 to .90 (roughly 0.1mag)
-then picked only V-R from 0.40 to 0.499 (roughly 0.1mag)
Result was 106 stars from mag 14.84 to 20.18 in a 10arcmin/sq field
Target very near zenith position.
18x75sec exposures
cam temp -11C
No darks or flats applied, no guiding used.
There were a few residual hot pixels that show up as linear 'chains'
in the image caused by lx200 long term RA drift after PEC training.
ugc10214 7/11/2002
16x120sec
Pseudo 'flat+dark' applied (from a different night)
cam temp -10C
M57 sequences
Cam temp -10C
Raw images, no darks or flats
16 raws per image
summed/integrated then averaged (/16)
lx200 10inch F10 @ F3
cropped then 2X resize
brightness adjust
Exposure time(sec) from upper left to lower right
1, 2
3, 4
5, 7.5
10, 15
20, 20
Analsys to follow for mag depth but it looks like ALL
exposure lengths reach at least some vestigal of
15.3mag (see indicated on 1sec exp) and also the
central star on all but not so pronounced becuase of
the brightness of the rings interior.
Ref image:
http://c3po.cochise.cc.az.us/astro/images/M57!dss2_3.jpg
line wrap?)
Note: lower right 20sec image is average of 8
exposures to show noise reduction offered by using 16 exposures.
The following is a reprocess of the 20sec raws to bring out
max mag depth. It also shows a nasty artifact of the firmware in
the cam head, namely 'ears' on the saturated stars. Theory on this
is it is from the filters the head applies on the high freq signal
components, namely low bright->high bright->low bright transitions.
The tick'ed star comes in at mag18.1.
