This form sets up the basic parameters for all of the objects and finder charts you'll create during this instance of the run.
Positions in the sky are given in the celestial coordinates system of right ascension and declination.
You begin by specifying the boundaries of the sky you'd like to observe for this run. Right ascension defaults to the sky that is 4 hours west and 5 hours east of your current sidereal time, based on what your computer's clock. This is what you get when you click "Make the list based on the current time". Click here to learn about sidereal time.
All of the defaults below are set by the defaultParameters file in the doc directory (folder). You can change any of them by editing the file with a text editor. If you use Word, and don't save it as a text only document, Night Assistant won't be able to read it.
Before you edit the file, make a backup copy of it, just in case.
You can change anything to the right of a colon. DO NOT change anything to the left of a colon.
Items that are numbers, like chart size and minimum magnitudes need to be numbers. No letters! Letters will confuse Night Assistant.
Once you've saved the new version, run Night Assistant to check that all of the parameters in the startup screen are OK.
Only change the text to the right of the colon in any line.
Are the declination limits of the list's boundaries.
Show, Don't Show: List only those object not seen before (as determined by your observations). The default is "Don't Show".
Stars brighter than the minimum bright star magnitude are listed.
Min and Max double star separation: Only doubles within these limits will be listed.
Dbl Primary: Only doubles with the primary component brighter than this limit will be listed.
Dbl Secondary: Only doubles with the secondary component brighter than this limit will be listed.
Variables: Only variables that get brighter than this will be listed.
Both local and sidereal time are shown. They update once per second.
Chart size: This is the linear chart size, in degrees. The default value of 3, for instance, will create charts that are 3x3 degrees in size. Currently, the program allows values between 1 and 5 degrees.
Eyepiece: This draws the field of view of an eyepiece around the center of the chart. The default is 60 minutes, or one degree.
Checkbox Dark BG: If checked (this is the default), this will draw colored stars on a dark blue background. If not, black stars on a white background.
Checkbox Reverse: If checked (this is the default), this will reverse the chart, with east on the right side and west on the left.
Checkbox Invert: If not checked (this is the default), north is at the top of the chart.
Observatory: Name of the location from where the observation was made.
Telescope: The telescope used for the observation.
The latitude and longitude of your observing site.
If set, a yellow line between the center of the chart and its edge, in the direction of the zenith will be shown on the chart.
Filter out objects dimmer than the given magnitude.
Uncheck any type of object you're not interested in seeing listed.
the string "STF" will list only the Struve doubles whose name have the "STF" string.Only objects with this string in their name will be listed. Note that this field is case sensitive.
Makes a finder chart of the named object. A good way, for example, to go directly to a Messier OR NGC object.
All the objects that passed the filters in the first form are displayed in the list that comes up after you click on the "Make the list" button in the previous form.
The first field is the right ascension, in hours and minutes. This is the format used by Burnham in his celebrated Celestial Handbook, and is easiest to use with analog setting circles.
The second field is the declination, in degrees.
Both right ascension and declination are precessed to "True of Date", that is for today's date.
The coordinates are followed by the object's name, and if it's a star, its spectral type, if known. NGC/IC objects are followed by Dreyer's short, cryptic, description.
At the bottom of the list is an item, "Add Solar System Object", with no coordinates. You can't make a finder chart of this, but you can use it to add an observation of a planet, asteroid, comet, ufo (Just kidding), etc.
The "Make Finder Chart" button makes a finder chart for the object, using the parameters you entered into the first form.
The "Add Observation" button adds a new observation for this object.
Invert toggles the North - South orientation of the field. If it's grayed out, the field is Not inverted and north is at the top.
Reverse toggles the East - West orientation of the field. If it's grayed out, the field is Not reversed and East is at the left.
Exit erases the chart.
Clicking on a star brings up its text data in the right hand column
When adding an observation, a form comes up that is keyed to the type of object you've observed.
Most laptops are egregiously bright when at the telescope, even in an urban environment. Under truly dark skies, they function as small street lights. I've managed to tame mine by taping sheets of clear red plastic over the screen.
A dim, red light that attaches to your hat is invaluable for lighting the keyboard.