# vStar 1.01 Beta User's Guide

| Introduction
| GPL Application
HowTo
| Load Records Search Records Save as CSV Save as Text
Glossary

| ## Introduction
| ### GPL top vStar - Searches & reports variable star records in AAVSO data file Copyright (C) 2005-2007 Frederick (Rick) Burton This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. ### Application top vStar performs a selection of searches for variable stars based on American Association of Variable Star Observers (AAVSO) records. These records are found in a public domain file available for download at http://www.aavso.org/observing/aids/vallongtype.txt . A supporting file explaining fields and layout of vallongtype.txt is found at http://www.aavso.org/observing/aids/valsampl.txt.

| ## HowTo
| ### Load Records top From the File menu, choose Load File. The standard data file is named vallongtype.txt. Multiple versions of this data file may be kept and loaded one at a time. Record format is validated on the fly while loading data. Only valid records are loaded while invalid records are disregarded. If a new data load is initiated, the previously loaded data is replaced by the newly loaded data. Linux: The title bar and status bar display info about loaded records. When a file load completes, the name of the data file is displayed in the title bar while the number of records loaded is displayed in the status bar. Windows: The upper left portion of the vStar screen captioned "Data" displays info about loaded records. When a file load completes, the name of the data file and the number of records loaded is displayed in this area. ### Search Records top Enter criteria values in the text boxes in the lower left portion of the vStar screen captioned "Search Criteria", then click either the Search Ascending button or the Search Descending button. The ascending search sorts records in their natural order as loaded from the data file while the descending search produces records in the reverse order. Search criteria text boxes are disabled when there are no records loaded. Right Ascension and Declination criteria specify an area of the sky to search. Magnitude and Period criteria set limits on variability behaviors of the stars to include in the search. Linux: The title bar displays info about searched records. When a search is performed, the number of records included in the search is displayed in the status bar. Windows: The upper left portion of the vStar screen captioned "Data" displays info about searched records. When a search is performed, the number of records included in the search result is displayed in this area. Check boxes When the "Mag:" check box is checked, these values are used in the current search. When unchecked, magnitude values are disregarded. When the "Period:" check box is checked, the minimum and maximum values are used in the current search. When unchecked, period length is disregarded. When the "No Lt. Curve" check box is checked, only stars with no magnitude or period values are included in the search. When unchecked, magnitude and period are used as specified. * TIP: With all three check boxes unchecked, every star in the designated region of the sky is displayed.
| #### Right Ascension top Hours are entered with values ranging from 0 to 23. The "West" value represents the western-most hour to search while the "East" value represents the eastern-most hour to search. When the same value is entered for West and East, only that hour is searched. Any values within the given range may be entered for either criteria. The hour 0 will be spanned when it is contained by the series of hours to be searched. #### Declination Degrees are entered with values ranging from -90 to 90. Negative values represent southern degrees and positive values represent northern degrees. The "South" value represents the southern-most declination to search while the "North" value represents the northern-most declination to search. Any values within the given range may be entered, but South must be less than North. #### Magnitude Maximum magnitude is entered as a positive floating-point value. This "Max >" value represents the lower limit of brightness (or upper limit of numeric value) for the maximum magnitude of the star´s brightness range. Minimum magnitude is entered as a positive floating-point value. This "Min <" value represents the upper limit of brightness (or lower limit of numeric value) for the minimum magnitude of the star´s brightness range. * TIP: The values 99 and 0 respectively for Max and Min will include any records with magnitude data. #### Period Days are entered as positive floating-point values. The "Least" and "Greatest" values represent the lower and upper limits of the period of time during which the star's brightness change cycles. * TIP: The values 0 and 99999 respectively for Min and Max will include any records with period length data.
### Save As CSV top From the File menu, choose Save CSV. The current search results will be saved in comma-separated format including column headers. This file may be loaded into most spreadsheet programs for any further formatting or analysis. ### Save As Text top From the File menu, choose Save Text. The current search results will be saved as a plain text file in the same native format as the original data file. The resulting file may be loaded into the program as a subset of the larger data file in order to perform a search within fewer records.

| ## Glossary top
| Right Ascension: Astronomical Longitude. Each hour equals 15 degrees and is divided into minutes and seconds of arc. Declination: Astronomical Latitude. Degrees mirror terrestrial latitude with negative numbers representing southern locations. Magnitude: Brightness Scale. Each whole number represents a change in brightness by a factor of 2.512 (5th root of 100) so that every five whole numbers represents a change in brightness by a factor of 100. Smaller values indicate greater brightness. A magnitude of 6.0 is naked-eye threshold. Period: Length of Brightness Variation Cycle. The duration of the entire brightness variation pattern expressed in decimal days. Light Curve: Variable star's changes in brightness over time represented as a graph - typically a somewhat wave-like curve.