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Parallax Help

The following list of help topics will link you to the appropriate section. To return to the list, click the back button on your navigation toolbar or scroll to the top of the page.


Browsing the Volumes

To browse the volumes by page image, go to the Browse page and select a volume.

The Table of Contents for the online version of the volume will be displayed. This URL can be bookmarked in your browser for recurring access. The Table of Contents contains links to major sections of the volume, including title page, table of contents, issue number, tables, observations, illustrations, and index. Clicking on a link will take you to that particular section of the volume.


Navigating and Viewing the Page Images

When you view a page image, you will also see a separate navigation frame at the bottom of your browser. This is what the various parts mean:

  • Previous Page takes you to the previous page in the volume.
  • Next Page takes you to the next page in the volume.
  • Go to Page # jumps to a desired page when you enter the page number in the adjacent box and click on the button. This feature is especially handy for moving from the table of contents to a particular section of the volume. (Note: The user must click the Go to Page # button for the feature to work.)
  • Page # indicates the number of the page you are viewing and the total number of pages in the volume.
  • View As sets the size of the image you are viewing. Choose between settings of 100%, 75%, 50%, and 25% (the default setting is 75%). The percentages are in a pull-down menu, and the size you choose will stay in effect until you change it or end your session. If you have a smaller monitor, you may want to choose a lower percentage. (Note: The View As button must be clicked to activate a size change.)
  • Table of Contents takes you to the table of contents to the online version of the particular volume.
  • Navigation Links at the bottom of the page connect to the search page, the home page for the Parallax Project, and the e-mail address for comments or questions.

Please note the appearance of the page image. What you are viewing is the actual scanned image of a page from the original volume. You should be aware that the format of the Parallax Project digital text poses certain problems:

  • All blank pages in the body of a volume are retained in the digital copy; therefore, do not be alarmed when you come across pages with no text.
  • Since each page is an actual scanned image, there are often large blank areas at the top of the page. If you have a smaller monitor, the text may not be visible at first, and you will have to scroll down the page to view it.
  • Although it is suggested that users with smaller monitors reduce the size of the image, please realize that the quality of the image will be much reduced. Viewing at 25% will probably make the text unreadable.
  • The scanned images of some illustrations may appear much darker than the original images. Viewing such images at 100% is recommended. Viewing them at a lower percentage will compromise the quality and detail of the illustration.

Several of the volumes contain introductory material, organizational history, etc. as front matter. From the volume's table of contents page image, use the Previous Page and Next Page buttons to view this text.


Searching the Volumes

The Parallax Project offers selective searching of the star data contained in the Publications of the Allegheny Observatory. The full-text is not searchable; therefore, it is important to use the Browse feature to view and navigate the contents of the volumes. See About the Project for information about the data-gathering process.

To search for selective star information, go to the Search page. You can search for star information by one or more of the following fields:

Allegheny Observatory (AO) Number: Search by unique identifier (i.e., running number) assigned to the individual stars by staff at the Allegheny Observatory. Enter an integer from 1 to 4 characters. This search will only return one result.

Star Name: Search by name of the star. The search will automatically truncate. For example, a search on andr will return a list of all Andromedae stars. Do not use abbreviations for star name. Use the virtual keyboard to enter Greek characters that precede an alphanumeric star name. (Note: some older Web browsers might not display the Greek characters correctly; please consider upgrading to the latest version of your browser.) For example, to search for α Andromedae, enter α andr (be sure to place a space after the Greek character). To search for a star name represented by superscripts and/or subscripts, you will have to enter the proper HTML code. For example, to search for star name W2 18h 979, enter W<sub>2</sub> 18<sup>h</sup> 979.

Right Ascension (RA1900): Search by the approximate right ascension of a star (1900 equinox). You must enter the entire position: hours, minutes and seconds. For example: 0:3:12 or 00:03:12 for α Andromedae. Please note that where RA values in the volumes included fractions of minutes, those fractions were converted into seconds for the purposes of consistency in the database.

Declination: Search by the approximate declination of a star. You must enter the entire position: degrees, minutes and seconds. For example: 28:32:00 or 28:32:0 for α Andromedae.

Parallax: Search for the parallax value for a star(s). Enter the arcsecond (include the decimal point). For example, a search on 0.0260 or .0260 or 0.026 or .026 will retrieve the same results. By default, a search is performed on a specific parallax value (e.g., equals). Use the pull-down menu to perform a search on a parallax value that is greater than or is less than the arc second entered in the search box.

Parallax Error: Search for the probable error of the parallax determined for a star(s). Enter the arcsecond (include the decimal point). For example, a search on 0.0073 or .0073 will retrieve the same results. By default, a search is performed on a specific parallax error value (e.g., equals). Use the pull-down menu to perform a search on a parallax error value that is greater than or is less than the arcsecond entered in the search box.

Click Submit Query to search or Reset to clear the search fields.


Search Results

The Search Results page displays the following information in column format:

  • Star Name
  • RA1900
  • Declination
  • AO No.
  • Parallax
  • Parallax Error
  • Page Images Available

During the data entry process, stars were assigned a study type depending on the context of their description within each volume: Light curve, Orbit, Radial velocity, Relative parallax, Spectroscopic binary, or Other. This information of "instance" is displayed in the Page Images Available column.

The AO Number, Parallax and Parallax Error values are only displayed for the star type: Relative parallax.

To view the specific page image for the individual star, click on the link containing the volume and page number. Please refer to the help section on Navigating and Viewing the Page Images for more information.

To determine the context of the page image within the volume, note the page number and select the Table of Contents link. Then scroll down the page to locate the appropriate section based on the page number.


Helpful Search Tip

Volume 10 is the only volume that published the relative parallax values apart from the individudal plate recordings. When following the link to a page image in Volume 10 from the Search Results page, you will be taken to the individual plate measurements for that star. The relative parallax values for each star in Volume 10 are located on pages 5-16 in AO number order.


Printing Page Images

  • To print a page from a volume, activate the image (page) screen by clicking in it and then select the print button on your navigation toolbar. For Mac users, select File > Print Frame... at 75% viewing size.
  • You may not be able to print at 75% (the default viewing size). At this size, some text will not fit on regular 8.5 x 11-inch paper. Change the viewing size to 50% instead, and then try printing. The text will not be as easy to read, but it should still be legible. It is unproductive to print at 25%, since you will not be able to read the text.
  • To change the viewing size, choose between settings of 100%, 75%, 50% and 25%. The percentages are in a pull-down menu, and the size you choose will stay in effect until you change it or end your session. (Note: The View As button must be clicked to activate a size change.)
  • Texts can only be printed page by page.
  • If needed, there are a series of steps to print a clean, non-distorted image:
    • For PC users, right click the page/image window and select "Save Image As..." on the pop-up menu. For Mac users, click on the page/image window; then under File, select "Save Image As..."
    • Save the image on your hard drive; it will save the file as a GIF by default.
    • Open up the GIF file in a graphics program (such as PhotoShop, Corel Photo House, or Microsoft Imaging application under Accessories).
    • Print the image from your graphics program (Note: the image file might take a long time to load and print).

The Digital Research Library realizes that printing capabilities are limited at the moment. We appreciate your patience until we can provide printing options that will better facilitate your research.


Citations

The University Library System, the Digital Research Library, and the Allegheny Observatory at the University of Pittsburgh welcome the citation of the online version of the Publications of the Allegheny Observatory of the University of Pittsburgh in scholarly writings. Relevant information should include the author's name, article title, and publication information of the original work; the title of the project and electronic publication information; and the date of access and the electronic address (URL).

Example: Baker, Robert H. (1910). The Orbits of the Spectroscopic Components of 2 Lacertae, Publications of the Allegheny Observatory of the University of Pittsburgh, 1 (13). Parallax Project, Digital Research Library, University of Pittsburgh. July 17, 2002 (http://digital.library.pitt.edu/parallax/01acr9511s/)