Astrophotography by Tomi Virtanen, galaxies, NGC2903

Galaxies, NGC2903

galaxies index
main index

Updates:

13.2.2005 - reprocessed image of 10.2.2005
10.2.2005 - created this page

Image list:

10.2.2005

Images:

10.2.2005

Target: NGC2903, galaxy
With background object: UGC5086 Date: 10.2.2005

Time: 23:52 .. 01:08 (10.2.2005)

Location: Vantaa, Finland

Conditions: Naked eye limit magnitude ~3.5.

Telescope: N150 f5 (GSO) Mount: GEM w RA stepper motor (Sky-View)

Camera: Art-429 (beta). TEC off.
Hi-res interlaced mode. (1x1) Filters: None

Exposure: 33.7 min (101 x 20s), dark frame (5 x 20s). Unguided & no PEC.

Processing: -

Images:
cropped full resolution image displayed

Notes:
My second DSO with the new Art-429 camera.
There is still some background gradients visible even though I managed to flatten the background quite a lot. It seems that I have to start to use flat fields since this new camera has so low noise that imperfections of the optical system show up much easier. The core of the galaxy was clipped during the processing, in the exposures it was in the linear range of the CCD.
Update 13.2.2005:
Reprocessed the image from start to achieve flatter background. Also corrected the pixel aspect ratio to square. The new version is shown. Old version is stored here for reference. No big difference achieved...

Images:

full resolution image displayed

Notes:
Update 13.2.2005:
There is also another galaxy visible in these images, the 15.7 magnitude UGC5086 that measures 54" across according to some catalogs. I made an inverted and scretched image of a part of the main image with a marker to show it up. The image is also rotated so that north is (almost) up, scale is approximately 2.4"/pixel.

email: tomi.virtanen@yahoo.de

Target:	NGC2903, galaxy With background object: UGC5086	Date:	10.2.2005
		Time:	23:52 .. 01:08 (10.2.2005)
		Location:	Vantaa, Finland
Conditions:	Naked eye limit magnitude ~3.5.
Telescope:	N150 f5 (GSO)	Mount:	GEM w RA stepper motor (Sky-View)
Camera:	Art-429 (beta). TEC off. Hi-res interlaced mode. (1x1)	Filters:	None
Exposure:	33.7 min (101 x 20s), dark frame (5 x 20s). Unguided & no PEC.
Processing:	-
Images:	cropped full resolution image displayed
Notes:	My second DSO with the new Art-429 camera. There is still some background gradients visible even though I managed to flatten the background quite a lot. It seems that I have to start to use flat fields since this new camera has so low noise that imperfections of the optical system show up much easier. The core of the galaxy was clipped during the processing, in the exposures it was in the linear range of the CCD. Update 13.2.2005: Reprocessed the image from start to achieve flatter background. Also corrected the pixel aspect ratio to square. The new version is shown. Old version is stored here for reference. No big difference achieved...
Images:	full resolution image displayed
Notes:	Update 13.2.2005: There is also another galaxy visible in these images, the 15.7 magnitude UGC5086 that measures 54" across according to some catalogs. I made an inverted and scretched image of a part of the main image with a marker to show it up. The image is also rotated so that north is (almost) up, scale is approximately 2.4"/pixel.