Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 10/25/2015 - 18:57
BT Lac appears to have a close companion. Using VPHOT Pixel mode I can move it out of the aperture. Saving the sequence does not repeat this solution. Unless there is another way to stick the solution, transforming using VPOT in these cases can not be used?
Clear Skies,
Mike
Hi Mike:
When I facilitated the last VPhot course we had a few discussions about this issue. It is always true that when a target has a close companion that things get difficult! The closer, the worse it gets.
From past trials with my own images, I was convinced that moving the aperture in pixel mode and saving it worked. It does appear that it is not that simple. It does appear that changing the search settings on the transform color photometry page may, but perhaps not always, fix this issue. The fact that there are search settings on this page indicates that simply saving the new centroid in a sequence is not enough to work in transforms of two images/filters.
So try to shrink the settings and use a fixed aperture and see if it helps? It is a feature issue that we will look at some time!
Ken
Thanks for the quick response, as always
Mike