User manual

ellipsoidal errors for the location, arrows for which the location and size are relative to

proper motion values …

Showing a filter in the stack

The filter is displayed as a peculiar plane in the stack and applies to all catalogue planes

located above the filter plane.

Using a predefined filter

Aladin has some predefined filters that correspond to the usual handlings in astronomy.

You can then select one of them and apply them instantaneously with the menu

“catalogue => Predefined filters”.

On the other hand, it is often useful to tune filter constrains and to do so, one needs to

create and edit the filtering rules manually. This is what is going to be detailed in the

following section.

Create a filter

A filter can be created

with the “filter” button in

the tool bar or with the

menu “catalogue =>

Create a filter”. Two

modes can be used

thanks to tabs:

 The “beginners” mode,

which is like using a

predefined filter (see

above);

 The “expert” mode

where you can edit

the filtering rules by

yourself.

The expert mode board

lets you edit filtering

rules in the central

edition box, and offers a

list of helps for the

writing: