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Orbital Elements Manager

The Orbital Elements Manager allows you to define and maintain orbital elements for comets and asteroids. These parameters are necessary to compute the position of an asteroid or comet at a given time. Deep-Sky Planner provides sophisticated tools to maintain these orbital elements which change any time a new object is discovered, or when the orbital solution of an object is refined. Orbital elements can be entered into Deep-Sky Planner in three ways:

▪by downloading data files from the Internet and importing them into the database

▪by importing data files previously downloaded with Deep-Sky Planner into the database

▪by adding the elements manually into the database

Orbital elements data files are made available courtesy of the IAU's Minor Planet Center (MPC) and NASA/JPL Solar System Dynamics (SSD). These are freely available for download from the Internet. Orbital elements for recently discovered or obscure objects may not appear in these update files, so these can be entered manually.

The Orbital Elements Manager is composed of a tabbed upper pane and a small lower pane. The upper Orbital Elements pane is used to display the orbital elements of comets and asteroids present in the database. The lower Update Status pane is used to report the progress and results of downloading and importing elements from a file. The status pane shows the progress of the file downloading and parsing portions of an import operation. You can review the messages in the status pane to verify the results of an import operation. The progress of adding data to the database is shown in the progress bar in the right portion of the window's status bar.

You can resize the panes by clicking and dragging the horizontal divider between the panes.

You can sort elements by clicking in the title area of any column to sort the elements in ascending order by that column's value; a subsequent click will toggle to descending order; Ctrl-click removes the sort specification.

Sorting does not function when there are a large number of objects (> 15,000) present.

You should compact your database after updating orbital elements! This is especially important if you import a data file.

Tool Bar

The tool bar contains speed buttons to various functions within the Orbital Elements Manager. The function triggered by clicking a tool bar button depends on whether you are viewing Comets or Asteroids. The functions are described below, but generally the buttons are:

Get Web

Get Web downloads orbital elements from an online source and imports the elements. Orbital elements are organized by object type (asteroid or comet) and naming class. Naming of object varies according to object type and source - MPC (Minor Planet Center) or SSD (NASA/JPL Solar System Dynamics).

The Get Web feature connects with the MPC or SSD web site, downloads the appropriate elements file, stores it on your local storage and adds the data to your database, marking these objects as Favorites ¹ or Un-Favorites as you wish. The progress of the update is shown in the status pane and the progress bar. Some of the files contain elements for many thousands of objects and take a lot of time to process.

Naming Class

Comets

▪MPC Periodic, period less than 200 years like 1P/Halley. A few hundred objects. Stored in CometEls.txt ²

▪MPC Provisional Periodic, period likely less than 200 years but only one apparition has been observed like P/2023 M4 (Atlas). A couple hundred objects. Stored in CometEls.txt ²

▪MPC Long Period, period greater than 200 years like C/2021 S3 (PanSTARRS). A couple hundred objects. Stored in CometEls.txt ²

▪MPC Other, unlike the other classes; like D/...(disappeared, like D/1993 F2-D (Shoemaker-Levy) ), A/...(possible asteroid, like A/2023 R3), I/... (interstellar, like 2I/Borisov), X/... (no reliable elements). Several dozen objects. Stored in CometEls.txt ²

▪SSD Periodic, period less than 200 years like 1P/Halley. A few hundred objects. Stored in ELEMENTS.COMET ²

▪SSD Provisional Periodic, likely period less than 200 years but only one apparition like P/2023 M4 (Atlas). A couple hundred objects. Stored in ELEMENTS.COMET ²

▪SSD Long Period, period greater than 200 years like C/2021 S3 (PanSTARRS). A few thousand objects. Stored in ELEMENTS.COMET ²

▪SSD Other, unlike the other classes; like D/...(disappeared, like D/1993 F2-D (Shoemaker-Levy) ), A/...(probably asteroid, like A/2023 R3), I/... (interstellar, like 2I/Borisov), X/... (no reliable elements). Several dozen objects. Stored in ELEMENTS.COMET ²

Asteroids

▪MPC Bright, like (1) Ceres. These usually have a number and a name. A few hundred objects. These asteroids reach opposition during the current year; stored in Soft00Bright.txt ²

▪MPC Critical, like (1915). These usually have a number but no name. Several hundred objects. These asteroids need to be observed so that their elements can be refined; stored in Soft00CritList.txt ²

▪MPC Distant, like (15760) Albion. A few thousand objects. These asteroids are Centaurs, Transneptunians and scattered disk objects; stored in Soft00Distant.txt ²

▪MPC Unusual, like (433) Eros. Orbits for asteroids with eccentricity ≥ 0.5 or Perihelion Distance from the Sun > 6 AU. Tens of thousands of objects. These asteroids are Near Earth objects (NEOs) and other unusual objects; stored in Soft00Unusual.txt ²

▪SSD Numbered, period less than 200 years like 1P/Halley. Hundreds of thousands of objects. Stored in ELEMENTS.NUMBR ²

▪SSD Unnumbered, likely period less than 200 years but only one apparition like P/2023 M4 (Atlas). Hundreds of thousands of objects. Stored in ELEMENTS.UNNUM ²

Get Local

Get Local imports the elements from previously downloaded files. Elements are organized as listed above (for Get Web)

New

New allows you to add elements for a new object using the Orbital Elements Editor. Objects whose elements are added become available for the Asteroid Ephemeris, Asteroid Search, Comet Ephemeris and Comet Search documents IF they are marked as Favorites ¹

You can add elements also by right clicking an object in the Orbital Elements pane and choosing New from the context menu

Edit

Edit allows you to edit elements for the selected object using the Orbital Elements Editor. Objects whose elements are edited become available for the Asteroid Ephemeris, Asteroid Search, Comet Ephemeris and Comet Search documents IF they are marked as Favorites ¹

You can edit elements also by right clicking an object in the Orbital Elements pane and choosing Edit from the context menu

Delete

Delete allows you to delete elements for one or more objects of the type shown on the selected tab (asteroid or comet).

▪Delete removes elements for the single selected object

▪Delete All removes elements for all objects of the type shown on the selected tab (asteroid or comet)

▪Delete All Un-Favorites removes elements for all objects of the type shown on the selected tab (asteroid or comet) and marked Un-Favorite

Favorite

Favorite allows you to change the Favorite ¹ status of one or more objects of the type shown (asteroid or comet). You may select Favorite objects from all the objects whose orbital elements are present. Favorite objects appear in the comet (or asteroid) documents so that you may select those objects for reports. Objects that aren't marked as Favorite do not appear in these documents, but their elements are still present if you wish to make them Favorite later. Since there are thousands of comets and asteroids available, marking selected ones as Favorite helps to manage the number of objects you see in the documents, and results in improved performance.

▪Toggle Favorite toggles the Favorite status for the selected object

▪Make All Favorites makes all objects of the type shown (asteroid or comet) Favorite

▪Make All UnFavorites makes all objects of the type shown (asteroid or comet) Un-Favorite

The Finder

Since there may be thousands of objects in the list, you can use Find to locate objects quickly. Enter a partial name and press Find. The search looks for a partial match in each object name so that if you search for 'XP14' for example, the search would locate 2004 XP14. Since the finder looks for partial matches, you do not need to use wildcard characters. If a matching name is found, it is selected in the list and the Find button changes to Next so that you can search further through the list. If no more matches are found, the status box beside Reset shows 'no more found'. If you want to start a new search, press Reset.

If a very large number of objects (> 15,000) are in the list, Find can only locate the first matching entry. The Reset button is disabled. This limitation is due to overall performance considerations.

Find/Next - initiates or continues a search for an object by designation in the elements pane

Reset - resets the finder by clearing the object designation and returning the search to the top of the list

Help - open this help topic

Notes

¹ Favorite objects may be selected in Asteroid Ephemeris and Comet Ephemeris documents, and may be searched in Asteroid Search and Comet Search documents. Objects that aren't marked as Favorite do not appear in these documents, but their elements are still present if you wish to make them Favorites later. Since there are many thousands of asteroids and comets available, marking selected ones as Favorite helps to manage the number of objects you see in the documents and results in improved performance.

²Orbital Elements files are stored in the application data folder for your installation, typically C:\Users\<user>\AppData\Roaming\Knightware\Deep-Sky Planner 9\Elements, where <user> is your Windows account. Any pre-existing elements file is overwritten when a set of elements is updated.

What About?

If you expected to find a comet or asteroid in an online update but cannot find it, then you should check both MPC and SSD for the elements.

If comet or asteroid ephemeris information appears to be inaccurate, the orbital elements most likely need to be updated. The orbital elements of comets and asteroids are revised periodically by the MPC and SSD, so you should check for updated orbital elements periodically.

Objects that appear in your database but not in an orbital elements file are left unaltered by Get Web or Get Local functions. This includes any objects you may have added using the Orbital Elements Editor.

If you do not check Favorite for an object's elements, you will not be able compute an ephemeris for it because the object will not be available to the ephemeris or search documents; however, the object's elements will be stored in the database so that you can make it a Favorite later, thereby making the object available to the ephemeris and search documents.

If you see 'Socket error 1100' in the status pane when you have attempted to download updated orbital elements, then you are not connected properly to the Internet. You must have a valid connection to the Internet to download orbital element files.

This research has made use of data and/or services provided by the International Astronomical Union's Minor Planet Center.