sky.objects {skyscapeR}

Creates a skyscapeR.object for plotting of celestial objects at given epoch

Description

This function creates an object containing all the necessary information to plot celestial objects/events unto the many plotting functions of skyscapeR package.

Usage

sky.objects(names, epoch, loc = FALSE, col = "red", lty = 1, lwd = 1)

Arguments

names

The name(s) of the celestial object(s) or event(s) of interest. These can be one of the following soli-lunar events: jS, dS, eq, nmnLX, nMjLX, smnLX, sMjLX, or the name of any star in the database. As shorthand, the names sun and moon can be used to represent all the above solar and lunar events, respectively. Alternatively, custom declination values can also be used.

epoch

The year or year range (as an array) one is interested in.

loc

(Optional) This can be either a vector with the latitude and longitude of the location, or a skyscapeR.horizon object.

col

(Optional) The color for plotting, and differentiating these objects. Defaults to red for all objects.

lty

(Optional) Line type (see par) used for differentiation. Only activated for single year epochs.

lwd

(Optional) Line width (see par) used for differentiation. Only activated for single year epochs.

Examples

# Create a object with solar targets for epoch range 4000-2000 BC:
tt <- sky.objects('solar extremes', c(-4000,-2000))

# Create an object with a few stars for same epoch:
tt <- sky.objects(c('Sirius', 'Betelgeuse', 'Antares'), c(-4000,-2000),
col=c('white', 'red', 'orange'))

# Create an object with solstices and a custom declination value:
tt <- sky.objects(c('December Solstice','June Solstice', -13), c(-4000,-2000))