Hello everyone. I am new to this forum. I have a rather urgent question about ImageJ. I am an astronomy postdoc in Canada and I have been using the “Concentric_Circles” plugin for my research and I found it very useful. It draws concentric circles on the object of interest in an image and sums up all the pixel values along the perimeter of each circle and calculates the mean as well. However, I was wondering if anyone knows of a way that we can exclude a wedge from the circles before calculating the mean? The problem I am having is that I am looking at an asteroid and want to get the mean intensity along each annulus; however, there is a nearby background star which I need to remove before taking the mean along each annulus. Does anyone have any idea how this can be done in ImageJ or know Java (I don’t) so we can write a plugin similar to Concentric_Circles but one that allows you to remove a piece of the pie that contains the star out of the annuli before calculating the mean along each annulus? I have sent an email to the author of the above plugin but while I am waiting for him to reply, I thought to ask here as well since my research is very time-sensitive and I need to figure out a way ASAP! Thank you very much in advance. - Maryam

P.S. I have attached a screenshot from my fits file so you see what I mean.

# Removing a wedge from Concentric_Circles before calculating the mean

**Maryam**#1

**etarena**#2

So, from what I understand… I’m not sure this is something that is limited by the plugin - but rather a separate pre-processing step that you could do to ‘eliminate’ the star. However, depending on exactly your aim for your analysis, I would caution from removing such data from your images. This would obviously greatly influence the outcome of your analysis.

Is it that you could mathematically remove those outlying circle measurements where the star is influencing the outcome? Perhaps others here have better insight… but I suppose we we understood a bit better the goal of your analysis - we could advise you more clearly.

eta