The page Daily ephemerides is designed to find all minima which occur on a specified night.
Start the program Ephemerides and click on the tab Daily ephemerides.
Enter a date which you want to compute data for. Specify date that is valid before midnight (evening date).
In the section Catalogues, check catalogues which shall be researched.
In the next section Filters, specify additional conditions for selecting variable stars and times of minimum. Only records that meet all conditions will be displayed.
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.
Cons - constellation abbreviation, e.g. And
Name - variable star designation, e.g. RT
PS - P for primary minimum, S for secondary minimum
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.
Az and 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).
R.A. and Dec. - equatorial coordinates of the object. A right ascension is shown in hours and minutes, a declination is presented in degrees.
Type - type of variability. Most frequently used abbreviations are:
Mag - brightness in minimum and maximum in magnitudes.
Catalogue - catalog designation, source of elements that were used for this ephemeris
Pts - for BRKA catalogue this value denotes a measure of usefulness of visual observation of the variable star. In user-defined catalogues, this field can be used to express a priority.
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.
Remarks - any remarks from the catalogue.
The data displayed in the table are sorted by its order in the catalogue files. It is possible to change
the sorting order. Click on a gray field in the table heading (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.
To save space, the first column combines variable star designation, followed by a colon if it is a secondary minimum (this used to be standard in the BRNO catalogue), followed by the constellation designation. For example: 'RT:And' is indicated that the row is ephemeris for a secondary minimum of RT And.
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.