System Requirements

This site is has been tested successfully on Mac OS X with Safari and Firefox, and on PC with Internet Explorer, with the exception that Firefox can not print the spectrum display applet window (see "Printing," below).

The Master Browse Table

The Browse page contains a table with atlas data for each of our planetary nebulae. The first column contains the common name for the object, and is a link to its spectrum display page (see "Viewing a Spectrum," below). The second and third columns give the equatorial coordinates: right ascension in hours and minutes, and declination in degrees and arcminutes, respectively. Positive or negative declination indicates position above or below the celestial equator. The fourth column lists galactic coordinates in the form "lll.l (sign)bb.b," where lll.l is the galactic longitude in degrees, and bb.b is the galactic latitude in degrees. The plus or minus sign before the galactic latitude indicates whether the object is above or below the galactic plane. The fifth column is a link to an image, either from the Digital Sky Survey or from other collections. The next three columns list distances from the sun, the galactic center, and the galactic plane, respectively. Distances from the galactic plane are listed without a plus or minus sign to allow proper sorting; these distances will be above or below the plane according to the sign of the galactic latitude being positive or negative, respectively. Literature references for distances are given on the individual spectrum pages. The final column lists the Peimbert type, which is related to an object's chemical and kinematical properties.

Re-ordering the Table

By default the table is ordered by object name. To re-order (sort) by any of the coordinate or distance columns in the table, click the pull-down menu for the sort key you want, and then click on the "Go" button.

Viewing a Spectrum

To see the spectrum of a particular planetary nebula, click on the object name in the Browse table. Be patient -- this may take up to 30 seconds. After the applet loads, you will see a full spectrum plot in a Java window. To zoom in on any region of the plot, hold the mouse down at one corner of the area you wish to enlarge, drag it to the opposite corner, and then release it. To zoom back out and redisplay the full spectrum, click the "Zoom Out" button at the bottom of the spectrum display. The spectrum display page also contains the information from the master table and literature references for the distance and abundance determinations. Saturated lines in the displayed spectrum, if any, are listed.

Line Identification Templates

Above the spectrum display window is a link to a set of plots, organized by wavelength, on which each emission line is identified by the ion producing it and its rest wavelength. These plots are in PDF format, and clicking on any one of them will open an Acrobat window and display that plot. Multiple template plots can be open at once; each will display in a separate window. It may be helpful to print out these templates.

Printing a Spectrum

The best way to print a nebula spectrum, except if you are using Firefox, is to use your browser's print button; this will print the entire browser window, but you can zoom first to enlarge the spectral region of interest. Firefox users can "grab" the spectrum display window and print it separately.