For a number of STIS apertures, it is possible to specify aperture names in the phase 2 proposal which put the target at different places within the same physical aperture. These include the 50CORON aperture, for which a number of different positions behind the wedges are defined (WEDGEA1.0, WEDGEB1.8, etc.), as well as the so-called "E1 positions" on the long slits (the "pseudo-apertures", with phase-2 aperture syntax "52X*E1"), which place the target near CCD row 900, close to the detector readout, in order to mitigate charge transfer inefficiency effects of the STIS CCD.
Unfortunately, the value of the "Aperture" field in the STScI archive databases is always set to be the name of the *physical* aperture used. E.g., observations that specified 52X2E1 in the phase 2 proposal will still be listed in the archive as having used the 52X2 aperture. Likewise, all observations done using the coronagraphic aperture will have 50CORON listed as their aperture value, regardless of the actual wedge location specified.
To search on the aperture names that were actually specified in the phase 2 proposal, it is necessary to access the value of the "propaper" field. This database field is not yet listed on any of the pre-defined StarView search forms, but it is easy to make a custom search form that will allow you to access it, as explained below.
To perform a search in StarView for data which have a proposed aperture different from the physical aperture used (e.g. E1 apertures), the qualifier for the proposal aperture should be included in the StarView search form. To do this, first open your favorite search form. Go to the top "View" menu and choose the option "Custom Query Generator". This will bring up the StarView Custom Query Generation tool. Select the option "Field" and in the search string window enter "propaper". Then select Keyword as the search option and start the search. This will bring all the database field names that have a keyword "PROPAPER". Double click in the fieldname "sss_propaper". If you have your form in "Static" mode you will get an information message to this effect, that asks if you want to continue editing. Select "Continue with editing" and the new field will appear at the bottom of the form and at the end of the list of qualifiers. While in the Edit mode you can move this field to any place in your search form by left clicking on the field name. Note that this will not change the order in which the fields appear in the list of qualifications. To move this qualifier up or down in the list, stay in Edit mode, right click on the Label field and choose the appropriate menu item.