(Return to David Chandler Company Home Page)

[The Help file for Deep Space contains three narative sections entitled Overview for Beginners, Overview for Active Observers, and Overview for Teachers. The following is based on the Overview for Active Observers section.]

Deep Space

OVERVIEW FOR ACTIVE OBSERVERS

I know who you are! You are the ones who keep Willmann-Bell and Sky Publishing Corp. in business. Your copies of Burnham's and Atlas 2000.0 are well worn, and the only reason your Uranometria isn't falling apart is it is nicely bound and you treat it with respect. Your RASC Handbook survives because it only has to last a for a year at a time. You plan your vacations around the phase of the moon and you consider a sunny day with high cirrus to be lousy weather.

I realize you probably own one or more planetarium programs already, but I think you will find Deep Space to be a little different. Deep Space was designed with you in mind, because I really wrote it for myself. I didn't sit down and write Deep Space. It grew. It has very little in the way of frills. If I spend time implementing a feature there has to be a payoff in functionality.

Allow me to illustrate with a star party preparation scenario.

You sit down a day or two in advance of new moon weekend, choose this month's star party site from your site list, set the date for the star party night, and bring up the Default Map. You have modified the configuration to plot the planets automatically. You check the "Currently Observable Comets" file on the Internet (linked through the David Chandler Company home page), so your comet files are kept up to date. You scan for all comets brighter than 13th magnitude and add them to the map. Perhaps you scan the asteroid list for a few you have been following. A nova was recently discovered, but its position was reported in 1950.0 coordinates. (Deep Space maps are all in 2000.0 coordinates.) No problem. You enter the coordinates, label them as having a 1950 equinox date and let the program do the conversions and pinpoint the object on the map. Now you print out the Default Map. This gives you an overview of the whole night's observable sky.

The all-night Default Map is my bid for the single most useful star party planning tool. You have the absolute limits with the sunset and sunrise horizons, and the more practical limits set for the astronomical twilight. The map is a true Mercator projection (see Extended Help, Mapping Basics) to keep shapes recognizable over the whole map, even though there is area distortion.

Now you zoom to each comet that is well positioned, add stars to an appropriate magnitude level, add the deep sky objects in the region that might be mistaken for the comet, and print out a finder chart for each one.

You go out to Begin New Map Stack and return to the Default Map with a clean slate. Now you turn your attention to the deep sky objects on your agenda. (Let's say you are working on the Herschel list.) A few months ago you created a category for your own use called "Project." You have been removing the objects from that category as you have logged them and any that were particularly impressive you added to another category you called "Fine Fuzzies." The "Project" category contains your current target list, so you display the whole category on the Default Map. The ones that fall within good areas of the sky you zoom in on and print out roughly constellation-sized finder maps. You label the target objects (thus adding them to the current observing list), then add the objects from the full database to put your target objects in context. If a label gets overwritten by an object you move the cursor near the object, jump to it, and move the label to a better location. After each map you exit to the MAIN MENU, select Logs/Lists/Categories, save the list with a name, for future reference, and print it out. The printed observing list shows the object name with all the catalog information, and (optionally) a rise/set time line, and any previous notes you entered.

A couple of galaxies you saw before impressed you and you decide to do sketches of them at the eyepiece. You seek each object by its Messier or NGC number and zoom into a Hubble Guide Star Catalog (GSC) map. The object shows up in the field, drawn with its correct size and orientation. For sketching purposes you want only the background stars, so you delete the object symbol. You add an appropriate eyepiece field of view circle, filter the GSC map to limit it to stars of a magnitude appropriate to your telescope, and you have your sketch area ready to draw the galaxy without having to plot all the field stars first.

You collect your maps together, staple each one to the corresponding observing list and put the maps into your RubberMaid storage clipboard (...hot new find for me! [as of the early 1990's] Maybe you have known about them for a long time...) along with your Night Sky planisphere and Night Reader LED flashlight. You have entered the age of "Clipboard Astronomy." You take your book bag along on the star party, but it sits in the back of the van most of the night as a reference library in case you happen on something you didn't expect. You sit on your stool at the eyepiece with your clipboard in hand equipped for a whole night's observing. You take your notes, do sketches of interesting star fields or star-hopping paths, cross off GSC stars that aren't really there (...it's a crude database, really, but boy is it deep!) and don't have to worry about messing up your expensive reference books.

When you return home, you bring up the saved observing lists one at a time and add your notes. You delete the lists to keep from cluttering up the directory. (The notes go into a single User Log, which is keyed to the main database. The observing lists are really just pointers into the User Log, so they aren't needed any more.) You delete the observed items from "Project" and add a few to "Fine Fuzzies," and you're done. Whenever you select one of these objects on the screen your observing notes will be right there with the original catalog data.

This scenario has variations, of course. If you have a laptop computer and digital setting circles you can enter your notes interactively. You can sweep for comets or simply sweep the Milky Way. At any time you can recenter the screen on the current position of the telescope and identify your current field of view. Deep Space can even help you recover comets by outlining the optimal search region for a returning comet that may be advanced or delayed in its orbit.

As of Ver. 5.53 we added a tool especially useful for variable star observers and supernova hunters. The support for "Auxiliary Objects" (formerly called "User-Defined Objects") has been expanded to allow you to create "Project Lists". Include the sequence of objects in your list that you want to monitor regularly. When you observe, choose a list to be the "Active List" then cycle forwards or backwards through the list with the <PgDn> and <PgUp> keys. If you have your telescope interfaced to the program you can point the telescope easily from one to the next. We have even included a list of variable stars selected from the GCVS catalog (brighter than mag. 10 at maximum) grouped by constellation.

Deep Space is a tool. Each of you will find your own innovative ways to use it to enhance your own observing projects. Let me know when you do.