The_Agent wrote:jgabany wrote:Hello:
The difference you have noted with the other stellar object is due to variances in the atmosphere when each of the two images were taken and the methods used to process each picture. This, in addition to other less noticeable differences, is an artifact that becomes apparent when comparing astronomical images of the same object taken under different observing conditions.
Thank you very much for reviewing my project and commenting. I appreciate it (a lot!)
I appreciate your response and everyone else who has added to such a exciting discussion, but i find that none of the other stars/objects in the surrounding area; appear to be showing the same variances, as evident by this one object.
So, i put forward the same question?, is this a new supernova or can we rule this out? also who would i contact to clarify this?.
![Smile :)](./images/smilies/icon_smile.gif)
Hi:
The pursuit of truth requires vigor and I respect your efforts to seek it out!
I have taken the time to re-inspect my images. First, let me explain how these photographs were created.
Because of the extreme faintness of astronomical objects, and this galaxy is extremely faint, a single snapshot is insufficient to capture enough light. Therefore, many exposures, each of several minutes duration with the camera shutter left open, are required. To produce both the left and right portions of this image, I had to take dozens of 15 minute images. Each image is called a sub-exposure. Most were to capture the light intensity, others added color.
So many exposures were required, that they could not be taken in a single night, so they were taken over a period of several days. During each sub-exposure, the conditions of the atmosphere through which the telescope viewed changed. Since several nights were required, that also introduced changes due to ongoing weather patterns.
Once all the sub's were acquired, they were combined using commercially available image processing programs specialized for astronomical photos and Photoshop, one of the most powerful image processing programs available on the market and widely used by photographers and the publishing industry. Combining sub exposures results in a single image, comprised of the sum of each sub-exposure. My combining method also applies an algorithm that attempts to weed out things that are unique to one or limited to a few of the sub-exposures so that the final single image is the mean of all the sub's.
If enough of the sub-exposures have a similar unique characteristic, then this will be reflected in the final master image.
This technique is not remarkable. It is used by both professional and amateur astronomical imagers. Similar techniques also are used to produce the wonderful images of the Hubble Space Telescope.
Therefore, late this morning, I reviewed the sub-exposures used to create the before and after sides of this image to see if there was anything that would indicate a change other than the presence of the supernova. I could not find anything. I did notice that several sub-exposures taken for the supernova image had stars that were a bit larger. This is due to poorer seeing conditions. There were enough sub-exposures in this set to affect the final master image and produce the appearance that the star to the right of the galaxy's center had grown (brighter).
I must also admit that the methods I use to process images continually evolves. Therefore, the right hand image showing the supernova was processed slightly differently than the earlier, left side image- taken at the beginning of this year. This is unavoidable.
Combined, both these differences result in the change you notice to the star right of the galaxy center in the right side image.
Dozens of professional astronomers have reviewed this image and commented by email. All have concurred with this explanation.
However, should this not convince you, the latest information regarding supernova discoveries can be found at the following URL. It is a clearing house to inform the astronomical community about these fascinating events:
http://www.supernovae.net/supernova.html
Additionally, all supernovas are reported through CBAT. Here's their web page:
http://cfa-www.harvard.edu/iau/cbat.html
Either of these web-sites can lead you to the leading experts on supernovas and this one in particular.
I hope this helps and I appreciate your interest in this project (a lot!)