Overview
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Position Criteria
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Select criteria values from the droplists in the upper left portion of the
vStar screen, then click the "Search" button.
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Right Ascension and Declination criteria specify an area of the sky to search.
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Alternately select a constellation from the drop-list just below Right
Ascension and Declination.
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TIP: The values 00 and 23 respectively for Right Ascension ,
then -90 and +90 respectively for Declination will include the entire sky.
Light Curve Criteria
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Magnitude and Period criteria set limits on variability behaviors of the stars
to include in the search.
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When the "Mag:" check box is checked, magnitude values are used in the current
search. When unchecked, magnitude values are disregarded.
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When the "Period:" check box is checked, the minimum and maximum values are
used in the current search. When unchecked, period length is disregarded.
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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.
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TIP: With all three check boxes unchecked, every star in the designated
region of the sky is displayed.
Refining Search Results
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Right Ascension
Hours are selected with values ranging from 00 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 selected for either criteria. The hour 00 will be spanned when it is
contained by the series of hours to be searched.
Declination
Degrees are selected 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.
Constellation
Constellations are selected from the "Constellation" drop-list. When any constellation
is selected, Right Ascension and Declination are disabled as coordinates will be
determined by constellation boundaries.
Magnitude
Maximum magnitude is selected as a positive 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.
Delta magnitude is selected as a positive value.
This "Delta" value represents the least amount of brightness
change for the star's complete period (See below).
TIP: The values 99 and 0 respectively for Max and Delta will include any
records with magnitude data.
Period
Days are selected as positive values. The "Least" and "Greatest"
values represent the lower and upper limits of the period of time, in days,
during which the star's brightness change completes one cycle.
TIP: The values 0 and 99999 respectively for Min and Max will include any
records with period length data.
No Light Curve
This option is selected to retrieve records for which there are no values for
either magnitude or period.
TIP: When this criteria is selected, both Magnitude and
Period criteria are disabled. With all three check boxes unchecked, Magnitude,
Period and No Light Curve, every star in the designated region of the sky is
displayed.
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