Information about the Sun and tools for building and understanding sundials.

Solar Info is a app that it provides information on Sun´s diurnal motion and Sun´s position during the year, which facilitates the understanding of some phenomena which, despite being familiar to us, we sometimes do not fully understand.

It is a useful tool for installation and setting of sundials because it provides an accurate solar time, calculated using astronomical algorithms.

Besides, there are a widget that can be placed anywhere in the home and shows the solar time at all times, sunrise and sunset times and the Sun´s relative position in the sky (when the Sun is visible).

The solar time in widget is updated both automatically and manually when touching anywhere on the widget area. When pushing on the icon on the top right corner of the widget, you can access the app menu.

The start screen now shows the solar time continuously, which is updated every second, as well as the sun Azimuth and Altitude, Equation of Time and UTC.

The Ephemeris section features the following information:

Latitude

Longitude

Sun altitude

Sun azimuth

Right Ascension

Declination

Distance

Morning Astronomical Twilight

Morning Nautical Twilight

Morning Civil Twilight

Sun rise

Transit

Sun set

Evening Civil Twilight

Evening Nautical Twilight

Evening Astronomical Twilight

Day lenght

Julian Day

Equation of Time

Local sideral Time

GMST

Logitude correction

UTC

Solar Time

Cast shadow

Spring Equinox

Summer Solstice

Autumn Equinox

Winter Solstice

In the Location section, the location coordinates can either be obtained featuring several options :

• Favourites list (offline).

• Using the integrated GPS (it is required that the location is activated).

• From the map (mobile data is required).

• Manual (offline).

• From an internal database containing 20.000 cities (offline).

It is now possible to change the location in the ephemeris module, which allows you to know the ephemeris of the Sun anywhere and at any time.

The ‘Equation of Time’ section shows a plot of the Equation of Time values. By moving the cursor, it is posible to see graphically the relationship between True Sun and Mean Sun as well as the value of Equation of Time for a specific date.

Graph of Analema and its components, displaying its value for each day.

Graph of daily Sun Path and hourly analemma. Possibility to add a horizon mask and the illumination limits for a horizontal or vertical declining dial.

It is posible to change the year for which the Equation of Time is calculated.

It is posible to export the data from the Equation of Time to an Excel file for subsequent processing in a PC.

The location of the widget is automatically updated every hour.

If the device is set to adjust the Time Zone automatically, the obtained precision may be in the order of ±5 seconds.

If you want to help translate the application into other languages, contact the support email.

Bibliography:

- "Astronomical algorithms". Jean Meeus

-" La gnomonique". Denis Savoie

-"Formule e metodi per lo studio degli orologi solari piani". Gianni Ferrari