It has often been said that if you have a Windows computer that is at, or coming to the end of its supported life; don’t discard it, install a Linux operating system and you will have a computer that is more secure and still very familiar to use.
For this session we used a Lenovo X270 Thinkpad with 8GB of RAM, a 6th generation i5 processor and a 256GB SSD drive. The computer was obtained via Amazon UK as a refurbished machine at a total cost of less than £150.
We installed Linux Mint; Wine that would enable us to run some Windows software; other software such as the Gimp 2.10 and AstroDMx Capture for Linux.
The telescope used was a William Optics Super Zenithstar 81mm ED Doublet APO refractor at f/5.5 with x 0.8 reducer/flattener, using an SVBONY SV605CC 14 bit, cooled, OSC CMOS camera and a Pegasus IR/UV cut filter. The scope was mounted on a Celestron AVX GOTO auto-guiding was done by PHD2 running on a separate computer using an SVBONY SV165 guide-scope fitted with a QHY-5II-M guide camera.
The equipment capturing flat fields
AstroDMx Capture capturing 30 x FITS flatfields
Stacked median flat field captured by this setup.
This image shows why it is important to capture flat fields.
As usual, the mount was placed on marks on the concrete base which give a fairly good polar alignment. AstroDMx Capture passed the time, altitude and location coordinates to the hand controller via the INDI server. The hand controller which now contained all of the correct information was set to its previous alignment and was unparked by AstroDMx Capture.
AstroDMx Capture was used to send the scope/mount to a bright star to check focus with a Bahtinov mask.
Focusing on Regulus
AstroDMx Capture, via the INDI server, sent the scope/mount to the main Copeland’s eyes galaxy NGC4438. AstroDMx Capture plate-solved the field of view and centred the object in the field of view.This galaxy is central to Markarian’s Chain of galaxies. This allowed a good framing of the chain.
AstroDMx Capture capturing 45 x 2 minute FITS exposures of Markarian’s Chain
Copeland’s Eyes can be seen in the centre of the image.
The data were calibrated and stacked in Siril and the stacked image was stretched and the background extracted to remove the gradient using GraXpert.
GraXpert showing stretched image with the gradient.
GraXpert showing the extracted background
GraXpert showing the gradient removed by background extraction
The Stretched, background extracted image was then denoised in Neat Image and post processed in Fitswork and the Gimp 2.10.
Markarian’s Chain
The image was submitted to Astrometry.net to identify a plethora of galaxies within the image.
The background extraction could have been done in Siril, but GraXpert was chosen to stretch the image and background correct all at once.
