/// <summary>
/// Calculates equatorial geocentric coordinates of Pluto for current epoch
/// </summary>
private CrdsEquatorial Pluto_Equatorial0(SkyContext c)
{
PrecessionalElements pe = Precession.ElementsFK5(Date.EPOCH_J2000, c.JulianDay);
CrdsEquatorial eq2000 = c.Get(Pluto_EclipticalJ2000).ToEquatorial(epsilonJ2000);
return(Precession.GetEquatorialCoordinates(eq2000, pe));
}
/// <summary>
/// Gets equatorial coordinates of a star for current epoch
/// </summary>
public CrdsEquatorial Equatorial(SkyContext c, ushort hrNumber)
{
Star star = Stars.ElementAt(hrNumber - 1);
PrecessionalElements p = c.Get(GetPrecessionalElements);
double years = c.Get(YearsSince2000);
// Initial coodinates for J2000 epoch
CrdsEquatorial eq0 = new CrdsEquatorial(star.Equatorial0);
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
eq0.Alpha += star.PmAlpha * years / 3600.0;
eq0.Delta += star.PmDelta * years / 3600.0;
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the star
eq += eq1 + eq2;
return(eq);
}
public override void Render(IMapContext map)
{
Graphics g = map.Graphics;
bool isGround = settings.Get <bool>("Ground");
bool isLabels = settings.Get <bool>("StarsLabels");
Brush brushNames = new SolidBrush(map.GetColor("ColorStarsLabels"));
if (map.MagLimit > 8 && settings.Get <bool>("Stars") && settings.Get <bool>("Tycho2"))
{
Brush brushStar = GetColor(map);
PrecessionalElements pe = Precession.ElementsFK5(map.JulianDay, Date.EPOCH_J2000);
var eq0 = map.Center.ToEquatorial(map.GeoLocation, map.SiderealTime);
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, pe);
SkyContext context = new SkyContext(map.JulianDay, map.GeoLocation);
tycho2.LockedStar = map.LockedObject as Tycho2Star;
tycho2.SelectedStar = map.SelectedObject as Tycho2Star;
var stars = tycho2.GetStars(context, eq, map.ViewAngle, m => MagFilter(map, m));
foreach (var star in stars)
{
if (!isGround || star.Horizontal.Altitude > 0)
{
PointF p = map.Project(star.Horizontal);
if (!map.IsOutOfScreen(p))
{
float size = map.GetPointSize(star.Magnitude);
if (map.Schema == ColorSchema.White)
{
g.FillEllipse(Brushes.White, p.X - size / 2 - 1, p.Y - size / 2 - 1, size + 2, size + 2);
}
g.FillEllipse(brushStar, p.X - size / 2, p.Y - size / 2, size, size);
if (isLabels && map.ViewAngle < 1 && size > 3)
{
map.DrawObjectCaption(fontNames, brushNames, star.ToString(), p, size);
}
map.AddDrawnObject(star);
}
}
}
}
}
/// <summary>
/// Gets equatorial coordinates of deep sky object for current epoch
/// </summary>
private CrdsEquatorial Equatorial(SkyContext c, DeepSky ds)
{
PrecessionalElements p = c.Get(GetPrecessionalElements);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(ds.Equatorial0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the object
eq += eq1 + eq2;
return(eq);
}
public override void Render(IMapContext map)
{
peFrom1950 = Precession.ElementsFK5(Date.EPOCH_B1950, map.JulianDay);
peTo1950 = Precession.ElementsFK5(map.JulianDay, Date.EPOCH_B1950);
Color colorGridEquatorial = map.GetColor("ColorEquatorialGrid");
Color colorGridHorizontal = map.GetColor("ColorHorizontalGrid");
Color colorLineEcliptic = map.GetColor("ColorEcliptic");
Color colorLineGalactic = map.GetColor("ColorGalacticEquator");
Color colorLineMeridian = map.GetColor("ColorMeridian");
penGridEquatorial.Color = colorGridEquatorial;
penGridHorizontal.Color = colorGridHorizontal;
penLineEcliptic.Color = colorLineEcliptic;
penLineGalactic.Color = colorLineGalactic;
penLineMeridian.Color = colorLineMeridian;
if (settings.Get <bool>("GalacticEquator"))
{
DrawGrid(map, penLineGalactic, LineGalactic);
}
if (settings.Get <bool>("EquatorialGrid"))
{
DrawGrid(map, penGridEquatorial, GridEquatorial);
DrawEquatorialPoles(map);
}
if (settings.Get <bool>("HorizontalGrid"))
{
DrawGrid(map, penGridHorizontal, GridHorizontal);
DrawHorizontalPoles(map);
}
if (settings.Get <bool>("EclipticLine"))
{
DrawGrid(map, penLineEcliptic, LineEcliptic);
DrawEquinoxLabels(map);
DrawLunarNodes(map);
}
if (settings.Get <bool>("MeridianLine"))
{
DrawGrid(map, penLineMeridian, LineMeridian);
}
}
private CrdsEquatorial StarEquatorial(SkyContext c, ConjunctedStar star)
{
PrecessionalElements p = c.Get(PrecessionalElements);
// Number of years, with fractions, since J2000 epoch
double years = (c.JulianDay - Date.EPOCH_J2000) / 365.25;
// Initial coodinates for J2000 epoch
CrdsEquatorial eq0 = new CrdsEquatorial(star.Equatorial0);
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
eq0.Alpha += star.PmAlpha * years / 3600.0;
eq0.Delta += star.PmDelta * years / 3600.0;
// Equatorial coordinates for the mean equinox and epoch of the target date
// without aberration and nutation corrections
return(Precession.GetEquatorialCoordinates(eq0, p));
}
/// <summary>
/// Gets equatorial coordinates of a star for current epoch
/// </summary>
public CrdsEquatorial Equatorial(SkyContext c, Nova n)
{
PrecessionalElements p = c.Get(GetPrecessionalElements);
double years = c.Get(YearsSince2000);
// Initial coodinates for J2000 epoch
CrdsEquatorial eq0 = new CrdsEquatorial(n.Equatorial0);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the star
eq += eq1 + eq2;
return(eq);
}
/// <summary>
/// Gets equatorial coordinates of a star for current epoch
/// </summary>
private CrdsEquatorial Equatorial(SkyContext context, Tycho2Star star)
{
PrecessionalElements p = context.Get(PrecessionalElements);
double years = context.Get(YearsSince2000);
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
var eq0 = star.Equatorial0 + new CrdsEquatorial(star.PmRA * years / 3600000, star.PmDec * years / 3600000);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eqN = Nutation.NutationEffect(eq, context.NutationElements, context.Epsilon);
// Aberration effect
var eqA = Aberration.AberrationEffect(eq, context.AberrationElements, context.Epsilon);
// Apparent coordinates of the star
eq += eqN + eqA;
return(eq);
}