Rob Hawley's Pages Almaden Observatory Main Page
Project Overview


This was the first section published in Dec 2014.  It consists of an ad hoc mosaic shown below.  Hopefully in 2016 I will be able to replace this with a more complete mosaic as indicated in the Project Overview

Map of Mosaic Area

Map of the current
click for a full size map.

Annotated Image

In many of my projects the Annotated Map is not very interesting.  It may label the odd bright star or NGC that was not the principle focus of the project.  In this case my final image is just a pretty picture without a detailed map.  The annotated image below is reduced in resolution from the full image below. Due to its size I am allowing you to zoom into it and explore. Alternatively you can look at the my extracts in the next section.

M52 Area Scrollable Image

Region Extracts

The full size image above is rather intimidating to navigate (even for me).  Thus I extracted several interesting areas from the full size image.  Click for a full size image.

Messier 52 / Bubble Nebula

M52 and Bubble Nebula in
        H alpha

SH2-142 (NGC 7380)

SH2-142 (NGC 7380) in A alpha







Processing Details

This image consists of 7 sections each composed of a number of 900 second images taken using the H alpha filter.  Section 3 was abandoned since there were no interesting objects observed. 

Plan of Mosaic

Number of Exposures of each section

* This was a section that joined section 2/6 to 5/8.

The sections were combined using GradientMergeMosaic.  This mostly worked, but I found I had to remove some bright stars from the edges using CloneStamp to prevent artifacts. However, I missed one.  I will leave it to the reader to find it.

When processing the images I chose to magnify the background nebulosity.  While the bright objects may have lost some contrast, I felt the overall result was better.  I did this by creating a mask using curves to isolate a section of the brightnesses  and then applied CurvesTransformation to the masked image.  You probably could have also done this directly, but I needed the mask anyway for noise reduction so I just repurposed it.

Masked stretch was used to improve the images of brighter stars.  Harry's shed provides an example of this process.

Copyrights For Photos

Creative Commons License
(c) 2014-2016 Robert J Hawley  Some Rights Reserved.
Except as noted,all work on this site by Robert J. Hawley is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. This permits the non commercial use of the material on this site, either in whole or in part, in other works provided that I am credited for the work.