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The Minor Planet Observer
Palmer Divide Observatory

2007 Shoemaker Grant Recipient

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MPO Canopus:
Making Plots for the Minor Planet Bulletin

MPO Canopus generates presentation quality plots of lightcurves. However, the raw plots are not the best for including in an article for the Minor Planet Bulletin, where space limitations require putting the most amount of information in the smallest area. This tutorial shows how to cut down a raw Canopus plot so that when imported as a graphic (not as an object, please!), it does not have large amounts of white space around it and yet the information is still easily read.

Outlined below are steps for when you have larger number of plots, say 4 or more, in a given article, such as when covering several asteroids. If the number of images in your article is only one or two, you can consider using larger plots. See step 1 below for additional information.

The method below should fit 8 plots per page comfortably.

For an example using small plots plots, refer "Asteroid Lightcurve Analysis at the Palmer Divide Observatory - Spring 2005", Minor Planet Bulletin, 32, 90-92.

It's better to use a good bitmap editing program than the simple Paint program provided with Windows. This tutorial was done using Graphic Works Magic.

Step 1. The Canopus Configuration

In the MPO Canopus configuration:

  1. Go to the Photometry Page
  2. Set the plot size to "Custom"
  3. Go to the Plotting Options tab
  4. Set the Width to 1024 and the Height to 675 pixels
  5. In most cases, you'll want to check the "Center on mean mag" box.

The custom size above fits 8 plots on an MPB page if no captions are included. This is acceptable, as long as each plot includes the name of the asteroid.

If you have only one or two plots for your article, use the 1200x900 setting available on the configuration page. Then follow the steps below, trimming the final graphic as shown. This will produce a larger plot that is a easier to read.

When using a "Custom" plot size and the "Show Header/Footer" box is checked, only the header is shown. The "Show Normalized Plot" setting is not important for this tutorial.


Step 2. The Raw Plot

  1. Generate the lightcurve plot and save it.

A typical raw plot with these settings is shown to the right. Note how the legend "hangs off" to one side, leaving lots of white space beneath it.

Per new recommendations from the MPB, only the left and bottom axes have values. This is now the default in MPO Canopus (v and above). This allows the data area of the graphic to be "larger" since the space required for the deleted values can be given back to the plot area.

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Step 3. Move the Legend and Add a Title and Footer

  1. The first step is to cut the legend and paste it back within the plot area. In some cases, where you have many sessions and the data fills the plot, you may have to split the legend into to two sections. 
  2. Using a 36 pt. bold font, Arial - Bold or Arial Black (normal), type in the name name of the asteroid at the top center of the plot area. If this would mean putting the title over data, then place the title to the left or right, but still at the top if possible.
  3. Per new MPB recommendations, you want to include the 0% phase JD and period with error within the plot area
  4. Cut and paste the JDo(LTC) line from the header and place it towards the bottom of the plot.
  5. Using a font of 20 pt. bold Arial or normal Arial Black, type in the period and error, also towards the bottom of the plot or where you can fit it in.
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Step 4. Trim the Plot

  1. Note the green dashed line around the plot in Step 3. This is the "cut" area that is used to trim the plot. It is tight against all margin.
  2. Using your program's tool that defines a region to copy, duplicate the cut region as closely as possible, making sure not to delete the values for the axes.
  3. Extend the copy region so that it includes the full height of the plot and just includes the vertical axis values on the right. The region will be about 875x560 pixels
  4. Copy the region to a new image and then save it, preferably as a 24-bit GIF. A JPEG can lose resolution and a 24-bit BMP is very large. If you try to save it as an 8-bit BMP (256 colors), this may result in dithering of the colors.
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Step 5. Insert the Plot

If you're using MS Word, please do not insert the plot as an embedded object. This can make the job for the editors very difficult.

The same applies for Excel plots - don't embed the Excel spreadsheet. Instead, take a screen shot and paste that in to your image editing program for touch up.


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This page was last updated on 01/19/11 15:43 -0700.
All contents copyright (c) 2005-2011, Brian D. Warner
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