NGC7000.COM
Comets and asteroids added to favorites in Coelix Apex

Not all the hundreds of comets and thousands of asteroids are present in the lists of current objects in the previous section.

COELIX APEX can search for other comets and other asteroids that are not in these lists. These may be for example newly discovered comets or asteroids that pass near the Earth.

These objects are added in a second list in Coelix Apex, the list of favorite comets or asteroids.

All objects registered in the lists of current objects and objects added to favorites are accessible in Coelix APEX, that is, they can be seen in Coelix views and their ephemeris can be displayed.

If an object (comet with the same name or asteroid with the same number) is present in both the list of MPC current objects and in the list of objects added to favorites, this is the one in the list of current objects which has priority, that is, which is visible in Coelix's views and whose ephemeris are displayed.

How to get the objects on the MPC website to add them to favorites

There are several ways to collect items from the Minor Planet Center website. You can go for an object by entering his name. You can also go for one or more objects in one of the several lists of objects available on the site.

The operation is always the same. This is to add new objects from the MPC list to the end of the list of favorites already present in Coelix Apex. The following sections provide examples of how to proceed.
Suggested text editor

It is necessary to use a good text editor to view and edit the cometfavor.txt and asterfavor.txt files.

It is not recommended to use the Notepad Editor provided with Windows since it does not always display end-of-lines and align columns of numbers correctly, which may prevent Coelix from reading these files without errors.

We recommend instead to use the free text editor Notepad ++ available on the Internet. You could even configure Windows so that Notepad ++ is the default application that displays files with the extension txt.

For text files, in the Notepad ++ Language menu, be sure to choose "Normal text". In the Encoding menu, choose "Encode in UTF-8".
Current comets and asteroids from the MPC (Minor Planet Center)


MPC Website




Add comets to favorite comets or asteroids to favorite asteroids from their names

Go first on the following page of the MPC website:

https://minorplanetcenter.net/iau/MPEph/MPEph.html

This page allows you to find the orbital elements of comets and asteroids simply by entering their names or numbers in the following edit box:
Here we give the example of the addition of three comets. Each added object must be on a different line. We could add one or more comets.

Nothing in the other parameters of the page should be changed. You only need to select the "SkyMap" format from the list of available software formats. Coelix uses the "SkyMap" format:
Click on the "GetEphemerides / HTML page" button and the MPC site sends you an elements.txt file that is probably in your Windows Downloads folder. Open this file and you should see the list of orbital elements of the three comets searched, displayed in the "SkyMap" format:
Using the mouse, select all characters from the three lines of the added comets. The goal is to copy and paste these three lines at the end of the existing favorite comets file. Make a copy (Ctrl-C).

Then open the cometfavor.txt file that contains the existing favorite comets. This file is in the main folder of Coelix Apex :
Place the cursor at the beginning of the line following the last line of elements (line 11 above) and paste (Ctrl-V) the three comets you copied:
You should see that the three new comets are added at the end of the list. Check that the columns of the elements of the added comets are aligned with those of the existing comets.

Save the cometfavor.txt file and check in Coelix Apex that the added comets are present:
Adding several asteroids to favorite asteroids from the asteroid lists on the MPC website

First go to the following page of the MPC website:

https://minorplanetcenter.net/iau/Ephemerides/Soft01.html

This page is used to display the orbital elements of asteroids in the "SkyMap" format used by Coelix by choosing them in several lists:
You can choose from one of the following three lists:

1- the list of critical numbered asteroids;
2- the list of distant asteroids;
3- the list of particular asteroids including NEOs.


You do not use the list of observable comets or bright minor planets at opposition because these lists are already used in a section at the beginning of this page to download the current MPC comets and bright current asteroids from the MPC.

By clicking on one of the choices, you get the list of desired orbital elements. This list can be quite long.

You proceed in the same way as to add the comets in the previous section. You copy and paste the elements of the selected asteroids to the end of the list of favorite asteroid elements found in the asterfavor.txt file contained in the main Coelix Apex folder. Also be careful to respect the alignment of the columns.
This update procedure is the only one available with both COELIX DEMO and COELIX APEX.

Adding a large number of asteroids to favorite asteroids with a list of consecutive asteroid numbers

First go to the following page of the MPC website:

https://minorplanetcenter.net/iau/MPEph/MPEph.html

This page allows you to find the orbital elements of comets and asteroids simply by entering their names or numbers in the following edit box:
By default, the list of favorite asteroids already contains the first 2000 asteroids numbered from 1 to 2000. But suppose we want to add the following 1000 by entering their numbers in the edit box above. It would be impossible since it would be too long. And unfortunately, there is no operator to enter a sequence of numbers such as "2001..3000".

That's why in the main folder of Coelix, we find a file that contains a list of numbers from 1 to 99000. You only have to open this file asternumbers.txt in Notepad ++ and to select consecutive numbers of asteroids that you want to add to your list of favorites, for example from 2001 to 3000 as shown here.

You just have to copy and paste these thousand numbers into the editing box shown above. It's a lot faster than entering one at a time.

Then choose the "SkyMap" format and click on the "GetEphemerides / HTML page" button. The MPC site sends you an elements.txt file that is likely to be in your Windows Downloads folder. Open this file and you should see the list of orbital elements of the thousand asteroids to be added, displayed in the "SkyMap" format.

You then proceed in the same way as in the previous sections. You copy and paste the elements of the selected asteroids to the end of the list of favorite asteroid elements found in the asterfavor.txt file contained in the main Coelix Apex folder. Always be careful to respect the alignment of the columns.
Updating comets and asteroids in COELIX

Orbits of comets and asteroids are easily disturbed by the gravitational attraction of large planets in the solar system, like Jupiter and Saturn, and even by the other planets like the Earth.The orbital elements of comets and asteroids (eccentricity, inclination, semi-major axis, etc.) can be modified when these bodies pass near large planets.

Because of this, these orbital elements are only valid for a limited period of time. For this reason and because we often discover new comets and asteroids, it becomes necessary to regularly update the database of comets and asteroids in COELIX. It is recommended to do updates at intervals ranging from two to six months. In this way, the software can generate accurate ephemeris and trajectories of these objects,

You can access the MPC files containing the orbital elements of current comets and brilliant asteroids that come in opposition during the current year, by clicking on one of the two buttons.

In each case, this brings up a web page of text format showing the list of orbital elements.

Save the page in the main folder of COELIX software, for example C:\NGC7000\CoelixApex, by using the function Save
_as... of your web browser and without changing the filename.
Even more precise ephemeris from the JPL HORIZONS System

All downloaded files above contain the orbital elements of comets and asteroids. Coelix uses the orbital elements (perihelion distance, inclination, semi-major-axis, etc..) to calculate the ephemeris and positions of comets and asteroids. These calculations give accurate results in most cases.

However, the downloaded orbital elements are osculatory, that is to say that they change over time and that they are only valid for a limited period. In addition, Coelix calculations do not include the effects of gravitational perturbations from objects other than the Sun, such as planets and large asteroids. So there may be a discrepancy in some cases, especially when a comet or asteroid passes close enough to Earth.

Since the 2.094 version, Coelix includes dozens of comets and asteroids whose ephemeris are directly calculated by the JPL Horizons system. These give very accurate ephemeris positions that reflect the gravitational perturbations.

Check the comethp and asterhp folders to see the files of these objects that are already present.

CLICK HERE to see how to add yourself comets and asteroids whose ephemeris are directly calculated by the JPL Horizons system and are not already present in the folders.