Hello,
My first attempt using Siril (1.4.0-beta4). I am having trouble plate solving a preprocessed image of C/2023 A3 taken October 2024. Was able to calibrate per instructions in manual, however I get " Plate Solving failed. The image could not be aligned with the reference stars." The image was relatively short exposure and only has about 90 detectable stars. I have tried various catalogs, including the bright star catalog, and playing around with the magnitude limit, as well as installing astrometry.net and no luck. As a sanity check, I tried plate solving an image of Orion, with about 2000 detectable stars, using the Siril solver and it worked (astrometry.net did not). Besides the comet, the image also has the horizon and some tree branches. Could these be causing the solver to fail? Would appreciate any advice.
Have you entered focal length and pixel size? That helps a lot. The other thing that helps as much is sky location.
Yes, to both.
You can draw a rectangle around the stars only and then plate solve. Works sometimes.