Trapezium Project – 2014-01-22

Imaging the trapezium – the multiple star cluster at the centre of the Orion Nebula (M42).

Equipment:

Scope: EdgeHD 11 (focal length 2800mm, f/10)
– astro-tech diagonal (too cold to refocus for straight through config)

Camera: Canon T2i modified with astrodon UV/IR filter
– Pixel pitch advertised as 4.30 um
– Width: 22.30 x 14.90mm
– Active Pixels: 5184 x 3456
– Astro SW though uses 5202 x 3465 pixels.

Mount: CGE Pro
– unguided, no PEC, PA hasn’t been done in awhile

I calculate the resolution of this optical train as 0.32 arc-sec per pixel.

However, a platesolve using Platesolve2 (by Dave Rowe) and the UCAC3PS catalog results in a resolution of 0.266 arc-sec per pixel.

From a run last year with the HD11, 5x powermate and a chameleon webcam i got this result:

Trapezium with 6 members resolved

Trapezium with 6 members resolved – 2013-04-01

 

The table below are the stacked versions of several different exposures.
– The picture is a tight crop of just the trapezium with a moderate stretch. Something akin to what the camera does for a non-linear jpg.
– The platesolve is the result of the platesolve2 on the fits file.
– the fits file is the full frame of a the stack of the calibrated and aligned lights for that exposure. The data is linear 16bit RGB.

To download a .fits files, right click and select “save as”. (Clicking on the link just opens up the .fit file as a text file, which isn’t any good at all.)

Note that all fits files are align to the same master. So its possible to combine the individual exposures into an HDR.

trap_1x4s_iso400.fit
integration: 4 * 1/4sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_1s_iso400.fit
integration: 2 * 1sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_2s_iso400.fit
integration: 4 * 2sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_3.2s_iso400.fit
integration: 5 * 3.2sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_5s_iso400.fit
integration: 5 * 5sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_10s_iso400.fit
integration: 6 * 10sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_30s_iso400.fit
integration: 5 * 30sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_30s_iso800.fit
integration: 7 * 30sec at ISO800
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_30s_iso1600.fit
integration: 6 * 30sec at ISO1600
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB