The page Star's ephemerides is designed to find all minima for a particular eclipsing binary star that occur in a specified season.
Start the program Ephemerides and click on the tab Star's ephemerides.
In the field Catalogue, choose the catalogue file that shall be researched.
In the next field Constellation, choose the constellation that the star is located in. Variables which do not include the name of the constellation in the name are enlisted in the OTHER group.
Select a star in the list of the Variable stars. The colon in the star's name indicates the secondary minimum.
Set up the interval of days that the ephemerides shall be computed for - section Date, fields from and to.
In the next section Filters, specify additional conditions for filtering minima, which shall be included in the results. Only the records which meet all conditions, will be displayed in the table.
Press the Update button to start the processing. The
results are displayed in the table. Every odd row is tinged by light gray color.
If you change the date or other settings, it is necessary to start the computation again.
Date and UT - date and time of minimum in Universal time. A date is always printed in the form year-month-day. A time is displayed in hours and it is always rounded to the nearest half-hour.
Day of week - days of week that corresponds to a local night, which the minimum occurs in. It is presented as the day of week before local midnight, slash and the day of week after midnight.
Julian date - Julian date of minimum.
Epoch - epoch (number of periods between the base minimum and the displayed minimum).
Az a Alt - apparent altitude of the object in degrees at the time of minimum. An azimuth is presented as an abbreviation of a direction, e.g. WNW is west-north-west. A value of azimuth in degrees can be found in the detailed information (see below).
Moon - Lunar disk illumination expressed in percents; an additional character denotes the trend: A plus sign means that the illuminated fraction is increasing, a minus sign means that it is decresing.
Obj-Moon - distance between the variable star and the Moon (disk center) at time of minimum in degrees. It is computed as an angle between two lines observer-object and observer-Moon.
The results displayed in the table are sorted by julian date by default. It is possible to sort
the items by other key. Click on a gray field in the table heading with field's name. You can also press the
Sort button on the toolbar. A context menu appears, select a sort key
from the menu.
It is possible to show detailed information on the selected eclipsing binary star and the selected
minimum by pressing the Info button on the toolbar. The information are displayed
in a separated floating panel. The panel consists of two tables located on separated tabs. The Catalogue tab shows
all information on the selected variable star. The Ephemeris tab includes computed results on the selected minimum -
predicted time of minimum, heliocentric correction, azimuth and altitude of the star in time of minimum and times of its
rise, transit and set. If the star do not rise/set, the stars are printed out in this fields. The values of the airmass
coefficient at the time of minimum, half an hour before and after the minimum are enlisted too.
The information panel stays on the top of the main window. By selecting another row in the table of minima, the content of the panel is automatically updated. You can hide the panel by clicking on the close button in its right top corner.
After coarse selection of the minima by means of the filters, it is possible to make fine selection
before printing or saving the table to a file. It allows you to make a final plan of an observation. To delete a particular
row or rows from the table, select them by clicking the left mouse button a press the Delete key or the Delete
button on the toolbar.
You can print the current content of the table on connected printer. Press the Print button
on the toolbar. The new window is displayed with a preview. In the window, press
Print button, check selection and settings of the printer and confirm by the OK button.
You can save the current content of the table to a file. Press the Save button
on the toolbar. The standard save dialog is displayed. You can choose between
several file formats - HTML, ASCII text or CSV.
Time of rising and setting of the Sun and Moon are also important for making observation plan,
especially for observations of eclipsing binary systems. This is why program also computes and displays this
information. Press the Sun button button to open a new dialog window.
The dialog shows the times of the sunrise, sunset and the start and the end of twilight. All times are in UT.
The next button Moon opens a similar dialog window. The
dialog shows the phase of the Moon at the date of selected minimum, times of rising and setting of the Moon. All
times are in UT.
It is possible to show a position of the selected variable star on an overview sky chart with
bright stars and constellations. Click on the Chart button . A new dialog
window appears. The dialog shows a sky chart centered on the variable star. The width of the viewfield is about
40 degrees. The cross in the middle of the chart marks the position of the variable star.