Lets start out by picking an observing date. How do you normally pick an observing date? Do you look at a lunar calendar and pick a new moon date? As it turns out, there are often 10 or more days where the moon will not interfere with a standard 3 hour observing session. NGCView helps you to quickly identify possible observing dates using its Planning Wizard. In the example below, the user selected a 2.5 hour observing session starting after sunset. NGCView displays a calendar in which dates with no moon interference are displayed in green,< 15% interference in yellow and > 15% interference in red.
Now that you've selected the date to observe, the next step is to select which objects to view. To make it to your observing list, objects must pass a two step process. The first step is to set up a filter which selects objects based on your filter criteria and places them on your filtered list. The second step involves reviewing the filtered list and transferring them to your observing list. Once an object has been transferred to the observing list, you can modify your filter criteria without losing the object. This allows you to do several specific filter operations and accumulate just the objects you want to see. This two stage approach is very important because it is often difficult to select all the objects you want to see in a single filter operation--a limitation of many astronomical planning programs. So as we continue with our quick tour, we will start selecting objects to view by removing objects we won't be able to see...
Most astronomy programs that do altitude filtering will do so for a particular moment in time, or perhaps they just display a horizon line on the chart. But as an observer, you are typically looking at objects for several hours, and the horizon is dynamic. NGCView has a unique filtering algorithm called a Time-Altitude window. This allows you to set a minimum and maximum altitude window through which an object must pass at some point during the observing session:
The standard approach to removing objects that are too dim is to use a total magnitude filter, however, total magnitude is irrelevant when it comes to extended objects unless the size of the object is taken into account. Take the Helix nebula for example, which has a total magnitude around 3 to 4. Some might expect that this would be naked eye visible (mag 3-4 stars can be seen naked eye even in light polluted skies). However, due to its great size, the light is distributed over a large surface area resulting in relatively dim surface brightness. While NGCView contains both a total magnitude filter and a surface brightness filter, its third brightness filter called a Dreyer Brightness filter is perhaps the best one to use to eliminate objects that are too dim to see. Dreyer was the original author of the New General Catalog (NGC) and he provided visual descriptions of brightness, size and shape. He used a 72" mirror for his observations, so this has to be taken into account when selecting filter criteria. After some experimentation with your equipment and observing conditions you can quickly determine the appropriate limit to use. We have found that 'Bright' through 'Most Extremely Bright' works well for a 6" Newtonian with average skies.
Now that we have removed objects that we can't see, its time to set additional filters to reduce the total number of objects down to a reasonable size to review. The filter selection dialog gives you hierarchical access to dialogs customized to handle your search criteria.
Once your filter preferences have been entered, you can select "OK" and NGCView will display those astronomical objects which passed your combined filter criteria. Objects are displayed in a three pane window; text, graph and chart panes:
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You can selectively expand any of the three panes to full screen:
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Once you have created your observing list, you can sort it in a variety of ways. While you can sort on the standard fixed data like RA or Transit time, NGCView has unique algorithms which creates optimized observing order based on a starting at the setting horizon and sweeping uniformly across the sky to the rising horizon. Options include the ability to bin this optimized observing order by Millenium, Uranometria or SkyAtlas chart.
You can print your observing list a variety of ways, from 1 to 8 objects per page. While the print graphic shows three panes per object, if you have selected full pane display on chart for example, you will get just the chart printed for each object.
After you have finished your observing, you can log your observations using NGCView's integrated observing log. Configurable drop down lists speed data entry. Note that the log will automatically transfer object data. A special log filter can locate objects based on any log field including searches of the log notes. The log, with or without the log filter activated, can be linked to NGCView's main filter so that you can eliminate objects that have already been seen. This is especially useful when doing Astronomical League certificate programs like the Herschel-1 or Herschel-2 lists.
Send your email comments to ngcview@rainman-soft.com.