*Load Spectrum*
To load a spectrum for classification:

    1)  Select "File"->"Unknown Spectrum" from the
        classification menu.

    2)  Make a selection from the sub-menu that appears:

        "Program List"
        Select from a list of program stars for this execise.

        "Next On List"
        Loads the next spectrum on the program list without displaying
        the list.  ("Program List" must have been selected previously.)

        "Saved Spectra (*.CSP)"
        Select from a list of spectra taken and saved for classification
        as part of this exercise.
  
The selected spectrum is loaded and displayed in the center of the
spectrum display area.

*Load Standard Spectra*
To load standard spectra for comparison:

    1)  Select "File"->"Atlas of Standard Spectra" from the
        classification menu.

    2)  Select an atlas from the list that appears.  You will normally
        begin with the Main Sequence to establish a temperature class
        before considering luminosity.

    3)  The atlas display will appear.  Note that the highlighted
        spectrum is displayed above the unknown in the display area,
        while the next atlas entry is displayed below the unknown.

    4)  Use the arrow buttons to peruse the atlas.  Note the progressive
        changes to the spectra as the stellar temperature changes.  When
        you have found a spectrum in the atlas that approximately
        matches the unknown, double-click the left mouse button with the
        cursor anywhere within the appropriate atlas entry.  The atlas
        entry will be highlighted and the standard spectrum will be
        displayed in the classification window.

*Measuring Spectral Features*
To measure the wavelength and intensity of a spectral feature:

    Press and hold the left mouse button - the cursor changes from an
    arrow to a crosshair.  As you move the cursor within the spectrum
    display area, the wavelength and relative intensity reading at the
    cursor are displayed at the bottom of the window.  When you have
    positioned the cursor at the point you wish to measure, release the
    mouse button. The readings will remain unchanged until the left
    mouse button is pressed again.

    NOTE:  If the spectrum is displayed as an intensity trace (see Help
    topic "Configure Display"), it is the vertical postion (Y coordinate)
    of the cursor that determines the intensity measurement.  If the
    display is in "Photo" mode, the intensity "under" the cursor (at the
    horizontal or X coordinate) is displayed.

See Also:
    "Marking Spectral Features"
    "Spectral Line Table & Help"


*Marking Spectral Features*
To mark a line or other spectral feature on the classification display:

    Move the cursor to the appropriate wavelength on any of the
    displayed spectra (unknown or standards) and double-click the left
    button.  A red line will appear at the selected wavelength from the
    top to the bottom of the display.  If a red line already appears on
    the display, it will move to the new location.  To remove an
    existing line, click the left mouse button once with the cursor
    anywhere within the spectra display area.

You can also mark a line by double-clicking its entry in the spectral
line table.

See Also:
    "Measuring Spectral Features"
    "Spectral Line Table & Help"

*Controls*
The following controls are located on the right-hand side of the
classification window:

    Standards Up/Down: Changes the displayed standards by one atlas
        entry in the selected direction.  The highlight on the atlas
        display also changes appropriately.

    Zoom In: Magnifies the displayed spectra by a factor of 2, up to a
        maximum of 16 times the original display.  If a feature is
        marked, the zoom attempts to center it in the magnified display.
        If no line is marked, the wavelength of the center of the
        display remains the same.

    Zoom Out: Decreases the magnification of the displayed spectra by a
        factor of 2, down to the original magnification (1X).  If a line
        is marked, the zoom attempts to keep it centered in the display.

    Zoom Arrows: Use the zoom arrow controls to scan across magnified
        spectra.

    Zoom Reset: Returns the display to the original (1X) images.  If a
        feature is marked, the mark is erased.

    Difference: The difference button changes the display so that the
        lower spectral standard is replaced by a plot of the point by
        point differences between the upper standard and the unknown
        spectrum (standard minus unknown at each point).  This can be
        very useful in determining the closest matching standard.

        Pressing the difference button a second time returns the display
        to it original form.

*Spectral Line Table & Help*
The spectral line table assists in the identification of spectral
features by wavelength, and includes a help facility that provides
information on the significance and use of each tabulated line in
stellar spectral classification.

To load the spectral line table, select "File"->"Spectral Line
Table" from the classification menu.

Features of the spectral line table:

    -Tracking Cursor-
    When the left mouse button is depressed with the cursor anywhere
    within the spectrum display, the wavelength of the cursor position
    is indicated on the spectral line table.  A single dashed line
    indicates that the cursor wavelength is between two entries in the
    table.  If two dashed lines surround a table entry, the cursor is at
    the wavelength of the line indicated (within about two angstroms).
    The table will scroll to track the cursor when the mouse is moved
    with the left button depressed.

    CAUTION: Judgement must be used in accepting line identifications
    from the table, since wavelength is the only criteria - temperature,
    luminosity, etc. are not taken into account.   For example, iron
    lines (Fe) do not appear in early-type stars, helium lines (He) do
    not appear in late-type stars, etc.

    -Marking Line Position-
    When the left mouse button is double-clicked on an entry in the
    spectral line table, the entry is highlighted and the position of
    the line is marked on the spectrum display.

    -Help-
    When the right mouse button is double-clicked on an entry in the
    spectral line table, the entry is highlighted and the line marked,
    as above, and a Help screen will appear with information about the
    selected line.

See Also:
    "Measuring Spectral Features"
    "Marking Spectral Features"

*Configure Display*
Options affecting the appearance and operation of the classification
window are available through the "File"->"Preferences" menu selection.

    "File"->"Preferences"->"Display"
    Sets the format of the spectrum display.

        "Intensity Trace"
            Displays spectra as plots of relative intensity vs
            wavelength (default).

        "Grayscale "Photo""
            Converts relative intensities to grayscale levels to mimic a
            (positive) photographic image.

        "Comb. (Photo & Trace)"
            Displays the unknown in both modes.  One standard is
            displayed as a "Photo".

        (The "Photo" option does not yield satisfactory results on
         16-color displays and so is disabled.)


    "File"->"Preferences"->"Pan Factor"
    Sets the pan factor parameter - the amount that the spectrum display
    shifts right or left when a pan button "<-" or "->" is pressed.
    Expressed as a fraction of the visible screen.

*Measure Equivalent Widths*
To measure the equivalent width of a spectral feature:

    1)  Zoom the display to a magnification that allows the "shoulders"
        of the line to be clearly identified and marked.

    2)  Mark the approxmate center of the line on the spectrum display,
        either by double-clicking the left button on the display itself
        or on the line entry in the table.

    3)  Mark the wavelength and intensity of both shoulders of the line
        by double-clicking the right mouse button with the cursor at
        each shoulder in turn.  The vertical position of the cursor
        should indicate the continuum level on each side of the line.
        If you have done this correctly the extents of the line will be
        delineated by a blue box, with the red line position marker
        passing somewhere near its center.  If you wish to change a
        position, simply move the cursor to the new position and
        double-click the right button again.  If you reposition the line
        center marker by double-clicking the left button, the blue
        markers will clear and will have to be set again.

    4)  When the feature is correctly delineated, select "Line
        Equivalent Width" from the classification menu.  A box will
        appear with the computed equivalent width, as well as
        wavelengths and intensities at the marked line center and
        shoulders.

*Save, Review, Analyze Results*
Facilities for recording and analyzing results are available under
"Classification Results" on the classification menu.

    "Classification Results"->"Record"
    When you have decided on a classification for a star, select
    "Classification Results"->"Record" and enter the classification, as
    well as any pertinent remarks, on the dialog that appears.  The
    entered data is placed in a table.
 
    "Classification Results"->"Review"
    This selection accesses the entire table of results you have been
    building.  Individual entries can be selected for revision, or
    deleted.

    "Classification Results"->"Save to File"
    When this option is selected, the entire table of results is
    written to a file, in a format (comma delimited text) that can be
    accessed by most spreadsheet programs.  Names from the login record
    and the date are included in the text for identification.  The file
    name is created from the first login name and carries the extention
    ".CSV".  You must save your data before you can print it (see
    below).

    "Classification Results"->"Print"
    This option is similar to "Save to File" except that the data is
    sent to the current Windows printer.  You cannot print your data
    until you have saved it (see above).

    "Classification Results"->"Spreadsheet"
    This selection accesses a spreadsheet program for analysis of the
    data.  You should not choose this option until you have completed
    all data taking and saved your results.  Once you have accessed the
    spreadsheet you will need to load the file (.CSV) you have created.
    The exact procedure will depend on the spreadsheet software.

    (The Spreadsheet option may not be available.)

*Leave Classification Window*
    To return to the main window, select "File"->"Return"->"Exit
    Classification Window".  The classification window will be
    minimized, and any recorded data and open windows (atlas and line
    table) will be retained and made available the next time the
    classification window is accessed.  To close the window, select
    "File"->"Return"->"Close Classification Window".  In this case, the
    atlas and line table are closed, and any recorded classifications
    that have not been saved and/or printed will be lost.

