org.hermit.astro
Interface AstroConstants

All Known Implementing Classes:
Body, Instant, Moon, Observation, Planet, Sun, Util

public interface AstroConstants

Definitions of useful global constants related to astronomical calculations.


Field Summary
static double ABERRATION
          The constant of aberration, κ.
static double AU
          One AU, in km.
static double HALFPI
          Half pi; a quarter circle in radians; same as 90 degrees.
static double J1900
          The Julian date of the 1900 Jan 0.5 epoch (which is actually noon, 31 Dec 1989) relative to the astronomical epoch of 4713 BC.
static double J1990
          The Julian date of the 1990 Jan 0.0 epoch (which is actually 31 Dec 1989) relative to the astronomical epoch of 4713 BC.
static double J2000
          The Julian date of the 2000 Jan 1.5 epoch (which is actually 1 Jan 2000 at noon) relative to the astronomical epoch of 4713 BC.
static double JD_UNIX
          The Julian date of the Unix/Java 1970 Jan 1.0 epoch relative to the astronomical epoch of 4713 BC.
static double REFRACTION
          The vertical displacement of an object due to atmospheric refraction -- 24 arcmins.
static double SECS_PER_DAY
          The number of seconds in a day.
static double SIDEREAL_RATIO
          The length of the sidereal year in mean solar days.
static double SIDEREAL_YEAR
          The length of the sidereal year in mean solar days.
static double TROPICAL_YEAR
          The length of the tropical year in mean solar days.
static double TWILIGHT
          The angle of the Sun below the horizon at the start / end of twilight, in radians.
static double TWOPI
          Two times pi; a circle in radians; same as 360 degrees.
static double ε_2000
          The obliquity of the ecliptic (angle between the ecliptic and the equator) at epoch 2000 Jan 1.5, in radians.
 

Field Detail

HALFPI

static final double HALFPI
Half pi; a quarter circle in radians; same as 90 degrees.

See Also:
Constant Field Values

TWOPI

static final double TWOPI
Two times pi; a circle in radians; same as 360 degrees.

See Also:
Constant Field Values

SECS_PER_DAY

static final double SECS_PER_DAY
The number of seconds in a day.

See Also:
Constant Field Values

JD_UNIX

static final double JD_UNIX
The Julian date of the Unix/Java 1970 Jan 1.0 epoch relative to the astronomical epoch of 4713 BC.

See Also:
Constant Field Values

J1900

static final double J1900
The Julian date of the 1900 Jan 0.5 epoch (which is actually noon, 31 Dec 1989) relative to the astronomical epoch of 4713 BC.

See Also:
Constant Field Values

J1990

static final double J1990
The Julian date of the 1990 Jan 0.0 epoch (which is actually 31 Dec 1989) relative to the astronomical epoch of 4713 BC.

See Also:
Constant Field Values

J2000

static final double J2000
The Julian date of the 2000 Jan 1.5 epoch (which is actually 1 Jan 2000 at noon) relative to the astronomical epoch of 4713 BC.

See Also:
Constant Field Values

ε_2000

static final double ε_2000
The obliquity of the ecliptic (angle between the ecliptic and the equator) at epoch 2000 Jan 1.5, in radians.


SIDEREAL_RATIO

static final double SIDEREAL_RATIO
The length of the sidereal year in mean solar days.

See Also:
Constant Field Values

SIDEREAL_YEAR

static final double SIDEREAL_YEAR
The length of the sidereal year in mean solar days.

See Also:
Constant Field Values

TROPICAL_YEAR

static final double TROPICAL_YEAR
The length of the tropical year in mean solar days.

See Also:
Constant Field Values

REFRACTION

static final double REFRACTION
The vertical displacement of an object due to atmospheric refraction -- 24 arcmins.


ABERRATION

static final double ABERRATION
The constant of aberration, κ.


TWILIGHT

static final double TWILIGHT
The angle of the Sun below the horizon at the start / end of twilight, in radians.


AU

static final double AU
One AU, in km.

See Also:
Constant Field Values