Functions: DE Ephemeris

Optional high-precision function variants that use JPL DE440/441 ephemeris files when configured via the pg_orrery.ephemeris_path GUC. Each function mirrors an existing VSOP87/ELP2000-82B counterpart with identical parameters and return types.

All DE functions are STABLE STRICT PARALLEL SAFE (except pg_orrery_ephemeris_info which is STABLE PARALLEL SAFE, not STRICT). When DE is unavailable, they fall back to their VSOP87/ELP2000-82B equivalents.

See the DE Ephemeris guide for setup and configuration.

---

planet_heliocentric_de

Computes the heliocentric ecliptic J2000 position of a planet using DE positions when available, falling back to VSOP87.

Signature

planet_heliocentric_de(body_id int4, t timestamptz) → heliocentric

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier: 0 (Sun), 1-8 (Mercury through Neptune)
t	timestamptz	Evaluation time

Returns

A heliocentric position in AU (ecliptic J2000 frame). Identical return type to planet_heliocentric().

Example

-- Compare DE vs VSOP87 heliocentric distances
SELECT body_id,
       round(helio_distance(planet_heliocentric(body_id, '2024-06-21 12:00:00+00'))::numeric, 10) AS vsop87,
       round(helio_distance(planet_heliocentric_de(body_id, '2024-06-21 12:00:00+00'))::numeric, 10) AS de
FROM generate_series(1, 8) AS body_id;

---

planet_observe_de

Computes the topocentric position of a planet using DE ephemeris for both the target and Earth positions.

Signature

planet_observe_de(body_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, excluding 3/Earth)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Caution

Body IDs 0 (Sun) and 3 (Earth) are not valid. Use sun_observe_de() for the Sun. Observing Earth from Earth raises an error.

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

Example

-- Mars position from Boulder using DE
SELECT round(topo_azimuth(t)::numeric, 4) AS az,
       round(topo_elevation(t)::numeric, 4) AS el,
       round(topo_range(t)::numeric, 0) AS range_km
FROM planet_observe_de(4, '40.0N 105.3W 1655m'::observer, now()) AS t;

---

sun_observe_de

Computes the topocentric position of the Sun using DE positions.

Signature

sun_observe_de(obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

Example

SELECT round(topo_azimuth(t)::numeric, 2) AS az,
       round(topo_elevation(t)::numeric, 2) AS el
FROM sun_observe_de('40.0N 105.3W 1655m'::observer, now()) AS t;

---

moon_observe_de

Computes the topocentric position of the Moon using DE positions. Falls back to ELP2000-82B when DE is unavailable.

Signature

moon_observe_de(obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

Example

SELECT round(topo_azimuth(t)::numeric, 2) AS az,
       round(topo_elevation(t)::numeric, 2) AS el,
       round(topo_range(t)::numeric, 0) AS range_km
FROM moon_observe_de('40.0N 105.3W 1655m'::observer, now()) AS t;

---

lambert_transfer_de

Computes a Lambert transfer orbit using DE-precision planet positions.

Signature

lambert_transfer_de(
    dep_body_id int4,
    arr_body_id int4,
    dep_time timestamptz,
    arr_time timestamptz
) → RECORD(c3_departure float8, c3_arrival float8, v_inf_dep float8, v_inf_arr float8, tof_days float8)

Parameters

Parameter	Type	Description
dep_body_id	int4	Departure planet (1-8)
arr_body_id	int4	Arrival planet (1-8, different from departure)
dep_time	timestamptz	Departure epoch
arr_time	timestamptz	Arrival epoch (must be after departure)

Returns

Transfer orbit parameters including departure and arrival C3 (km^2/s^2), v-infinity magnitudes, and time of flight.

Example

-- Earth-Mars transfer window with DE positions
SELECT round(c3_departure::numeric, 2) AS c3_dep,
       round(c3_arrival::numeric, 2) AS c3_arr,
       round(tof_days::numeric, 1) AS tof
FROM lambert_transfer_de(3, 4, '2026-05-01 00:00:00+00', '2027-01-15 00:00:00+00');

---

lambert_c3_de

Returns only the departure C3 (km^2/s^2) from a Lambert transfer computation using DE positions. A convenience wrapper around lambert_transfer_de().

Signature

lambert_c3_de(dep_body_id int4, arr_body_id int4, dep_time timestamptz, arr_time timestamptz) → float8

Example

-- Pork chop grid with DE accuracy
SELECT dep::date AS departure,
       arr::date AS arrival,
       round(lambert_c3_de(3, 4, dep, arr)::numeric, 2) AS c3
FROM generate_series('2026-04-01'::timestamptz, '2026-08-01'::timestamptz, '14 days') dep,
     generate_series('2026-12-01'::timestamptz, '2027-04-01'::timestamptz, '14 days') arr
WHERE arr > dep + interval '90 days';

---

galilean_observe_de

Computes the topocentric position of a Galilean moon of Jupiter. Uses DE for Jupiter’s heliocentric position and L1.2 theory for the moon’s offset.

Signature

galilean_observe_de(moon_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
moon_id	int4	0=Io, 1=Europa, 2=Ganymede, 3=Callisto
obs	observer	Observer location
t	timestamptz	Observation time

Example

-- All four Galilean moons with DE-precision Jupiter
SELECT moon_id,
       CASE moon_id WHEN 0 THEN 'Io' WHEN 1 THEN 'Europa'
                    WHEN 2 THEN 'Ganymede' WHEN 3 THEN 'Callisto' END AS moon,
       round(topo_elevation(galilean_observe_de(moon_id, '40.0N 105.3W 1655m'::observer, now()))::numeric, 2) AS el
FROM generate_series(0, 3) AS moon_id;

---

saturn_moon_observe_de

Computes the topocentric position of a Saturn moon. Uses DE for Saturn’s heliocentric position and TASS17 theory for the moon’s offset.

Signature

saturn_moon_observe_de(moon_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
moon_id	int4	0=Mimas, 1=Enceladus, 2=Tethys, 3=Dione, 4=Rhea, 5=Titan, 6=Iapetus, 7=Hyperion
obs	observer	Observer location
t	timestamptz	Observation time

---

uranus_moon_observe_de

Computes the topocentric position of a Uranus moon. Uses DE for Uranus’s heliocentric position and GUST86 theory for the moon’s offset.

Signature

uranus_moon_observe_de(moon_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
moon_id	int4	0=Miranda, 1=Ariel, 2=Umbriel, 3=Titania, 4=Oberon
obs	observer	Observer location
t	timestamptz	Observation time

---

mars_moon_observe_de

Computes the topocentric position of a Mars moon. Uses DE for Mars’s heliocentric position and MarsSat theory for the moon’s offset.

Signature

mars_moon_observe_de(moon_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
moon_id	int4	0=Phobos, 1=Deimos
obs	observer	Observer location
t	timestamptz	Observation time

---

planet_equatorial_de

Computes the geocentric apparent equatorial coordinates (RA/Dec) of a planet using JPL DE ephemeris. Falls back to VSOP87 plus the equatorial conversion when DE is unavailable.

Signature

planet_equatorial_de(body_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, excluding 0 and 3)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

-- Compare DE vs VSOP87 equatorial coordinates for Mars
SELECT round(eq_ra(planet_equatorial(4, now()))::numeric, 6)    AS ra_vsop87,
       round(eq_ra(planet_equatorial_de(4, now()))::numeric, 6) AS ra_de,
       round(eq_dec(planet_equatorial(4, now()))::numeric, 6)    AS dec_vsop87,
       round(eq_dec(planet_equatorial_de(4, now()))::numeric, 6) AS dec_de;

---

moon_equatorial_de

Computes the geocentric apparent equatorial coordinates (RA/Dec) of the Moon using JPL DE ephemeris. Falls back to ELP2000-82B plus the equatorial conversion when DE is unavailable.

Signature

moon_equatorial_de(t timestamptz) → equatorial

Parameters

Parameter	Type	Description
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

-- Moon RA/Dec via DE
SELECT round(eq_ra(e)::numeric, 4)       AS ra_hours,
       round(eq_dec(e)::numeric, 4)      AS dec_deg,
       round(eq_distance(e)::numeric, 0) AS dist_km
FROM moon_equatorial_de(now()) AS e;

---

galilean_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Galilean moon using JPL DE ephemeris for Jupiter’s position. Falls back to VSOP87 for both Jupiter and Earth when DE is unavailable. Moon offsets always come from Lieske L1.2 theory.

Signature

galilean_equatorial_de(moon_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
moon_id	int4	0=Io, 1=Europa, 2=Ganymede, 3=Callisto
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

-- All 4 Galilean moons via DE
SELECT moon_id,
       round(eq_ra(galilean_equatorial_de(moon_id, now()))::numeric, 4) AS ra,
       round(eq_dec(galilean_equatorial_de(moon_id, now()))::numeric, 4) AS dec
FROM generate_series(0, 3) AS moon_id;

---

saturn_moon_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Saturn moon using JPL DE ephemeris for Saturn’s position. Falls back to VSOP87 when DE is unavailable. Moon offsets come from TASS 1.7 theory.

Signature

saturn_moon_equatorial_de(moon_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
moon_id	int4	0=Mimas, 1=Enceladus, 2=Tethys, 3=Dione, 4=Rhea, 5=Titan, 6=Iapetus, 7=Hyperion
t	timestamptz	Evaluation time

Example

-- Titan's position via DE
SELECT round(eq_ra(saturn_moon_equatorial_de(5, now()))::numeric, 4) AS ra,
       round(eq_dec(saturn_moon_equatorial_de(5, now()))::numeric, 4) AS dec;

---

uranus_moon_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Uranus moon using JPL DE ephemeris for Uranus’s position. Falls back to VSOP87 when DE is unavailable. Moon offsets come from GUST86 theory.

Signature

uranus_moon_equatorial_de(moon_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
moon_id	int4	0=Miranda, 1=Ariel, 2=Umbriel, 3=Titania, 4=Oberon
t	timestamptz	Evaluation time

Example

-- Titania's position via DE
SELECT round(eq_ra(uranus_moon_equatorial_de(3, now()))::numeric, 4) AS ra,
       round(eq_dec(uranus_moon_equatorial_de(3, now()))::numeric, 4) AS dec;

---

mars_moon_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Mars moon using JPL DE ephemeris for Mars’s position. Falls back to VSOP87 when DE is unavailable. Moon offsets come from MarsSat analytical theory.

Signature

mars_moon_equatorial_de(moon_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
moon_id	int4	0=Phobos, 1=Deimos
t	timestamptz	Evaluation time

Example

-- Both Mars moons via DE
SELECT moon_id,
       round(eq_ra(mars_moon_equatorial_de(moon_id, now()))::numeric, 4) AS ra,
       round(eq_dec(mars_moon_equatorial_de(moon_id, now()))::numeric, 4) AS dec
FROM generate_series(0, 1) AS moon_id;

---

pg_orrery_ephemeris_info

Returns diagnostic information about the current ephemeris provider.

Signature

pg_orrery_ephemeris_info() → RECORD(provider text, file_path text, start_jd float8, end_jd float8, version int4, au_km float8)

Note

This function is STABLE PARALLEL SAFE but not STRICT --- it takes no arguments and always returns a row.

Returns

Column	Type	Description
provider	text	'VSOP87' or 'JPL_DE'
file_path	text	Path to the DE file (empty string if no DE)
start_jd	float8	First Julian Date covered by the DE file
end_jd	float8	Last Julian Date covered by the DE file
version	int4	DE version number (440, 441, etc.)
au_km	float8	Astronomical Unit in km from the DE header

Example

-- Check current provider
SELECT (pg_orrery_ephemeris_info()).provider;

-- Full diagnostic
SELECT * FROM pg_orrery_ephemeris_info();

---

lagrange_heliocentric_de

Computes the heliocentric ecliptic J2000 position of a Sun-planet Lagrange point using DE planet positions. Falls back to VSOP87 if DE is unavailable.

Signature

lagrange_heliocentric_de(body_id int4, point_id int4, t timestamptz) → heliocentric

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

A heliocentric position in AU (ecliptic J2000 frame). Identical return type to lagrange_heliocentric().

Example

-- Compare DE vs VSOP87 for Sun-Earth L1
SELECT round(helio_distance(lagrange_heliocentric(3, 1, now()))::numeric, 6) AS vsop87,
       round(helio_distance(lagrange_heliocentric_de(3, 1, now()))::numeric, 6) AS de;

---

lagrange_observe_de

Computes the topocentric position of a Sun-planet Lagrange point using DE planet positions. Falls back to VSOP87 if DE is unavailable.

Signature

lagrange_observe_de(body_id int4, point_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
point_id	int4	Lagrange point (1-5, L1 through L5)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

Example

SELECT round(topo_elevation(lagrange_observe_de(3, 2, '40.0N 105.3W 1655m'::observer, now()))::numeric, 2) AS el;

---

lagrange_equatorial_de

Computes the geocentric apparent equatorial coordinates (RA/Dec) of a Sun-planet Lagrange point using DE planet positions. Falls back to VSOP87 if DE is unavailable.

Signature

lagrange_equatorial_de(body_id int4, point_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

SELECT round(eq_ra(lagrange_equatorial_de(3, 2, now()))::numeric, 4) AS ra,
       round(eq_dec(lagrange_equatorial_de(3, 2, now()))::numeric, 4) AS dec;

---

lagrange_distance_de

Computes the distance in AU between a given heliocentric position and a Sun-planet Lagrange point, using DE planet positions. Falls back to VSOP87 if DE is unavailable.

Signature

lagrange_distance_de(body_id int4, point_id int4, pos heliocentric, t timestamptz) → float8

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
point_id	int4	Lagrange point (1-5, L1 through L5)
pos	heliocentric	Position to measure distance from
t	timestamptz	Evaluation time

Returns

Distance in AU between the given position and the Lagrange point.

Example

SELECT round(lagrange_distance_de(
    5, 4,
    lagrange_heliocentric_de(5, 4, now()),
    now()
)::numeric, 10) AS self_distance;

---

lagrange_distance_oe_de

Computes the distance in AU between an object described by orbital elements and a Sun-planet Lagrange point, using DE planet positions. Falls back to VSOP87 if DE is unavailable.

Signature

lagrange_distance_oe_de(body_id int4, point_id int4, oe orbital_elements, t timestamptz) → float8

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
point_id	int4	Lagrange point (1-5, L1 through L5)
oe	orbital_elements	Orbital elements of the object
t	timestamptz	Evaluation time

Returns

Distance in AU between the object and the Lagrange point.

Example

-- Trojan proximity with DE accuracy
SELECT round(lagrange_distance_oe_de(5, 4, oe, now())::numeric, 4) AS dist_au
FROM mpc_asteroids WHERE name = '(588) Achilles';

---

lunar_lagrange_observe_de

Computes the topocentric position of an Earth-Moon Lagrange point using DE positions. Falls back to ELP2000-82B if DE is unavailable.

Signature

lunar_lagrange_observe_de(point_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
point_id	int4	Lagrange point (1-5, L1 through L5)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

Example

SELECT round(topo_elevation(lunar_lagrange_observe_de(1, '40.0N 105.3W 1655m'::observer, now()))::numeric, 2) AS el;

---

lunar_lagrange_equatorial_de

Computes the geocentric apparent equatorial coordinates (RA/Dec) of an Earth-Moon Lagrange point using DE positions. Falls back to ELP2000-82B if DE is unavailable.

Signature

lunar_lagrange_equatorial_de(point_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

SELECT round(eq_distance(lunar_lagrange_equatorial_de(1, now()))::numeric, 0) AS dist_km;

---

galilean_lagrange_observe_de

Computes the topocentric position of a Galilean moon Lagrange point. Uses DE for Jupiter’s heliocentric position and L1.2 theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

galilean_lagrange_observe_de(body_id int4, point_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
body_id	int4	0=Io, 1=Europa, 2=Ganymede, 3=Callisto
point_id	int4	Lagrange point (1-5, L1 through L5)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

Example

SELECT round(topo_elevation(galilean_lagrange_observe_de(0, 4, '40.0N 105.3W 1655m'::observer, now()))::numeric, 2) AS el;

---

galilean_lagrange_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Galilean moon Lagrange point. Uses DE for Jupiter’s heliocentric position and L1.2 theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

galilean_lagrange_equatorial_de(body_id int4, point_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
body_id	int4	0=Io, 1=Europa, 2=Ganymede, 3=Callisto
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

SELECT round(eq_ra(galilean_lagrange_equatorial_de(0, 4, now()))::numeric, 4) AS ra;

---

saturn_moon_lagrange_observe_de

Computes the topocentric position of a Saturn moon Lagrange point. Uses DE for Saturn’s heliocentric position and TASS17 theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

saturn_moon_lagrange_observe_de(body_id int4, point_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
body_id	int4	0=Mimas, 1=Enceladus, 2=Tethys, 3=Dione, 4=Rhea, 5=Titan, 6=Iapetus, 7=Hyperion
point_id	int4	Lagrange point (1-5, L1 through L5)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

---

saturn_moon_lagrange_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Saturn moon Lagrange point. Uses DE for Saturn’s heliocentric position and TASS17 theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

saturn_moon_lagrange_equatorial_de(body_id int4, point_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
body_id	int4	0=Mimas, 1=Enceladus, 2=Tethys, 3=Dione, 4=Rhea, 5=Titan, 6=Iapetus, 7=Hyperion
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

SELECT round(eq_ra(saturn_moon_lagrange_equatorial_de(5, 1, now()))::numeric, 4) AS titan_l1_ra;

---

uranus_moon_lagrange_observe_de

Computes the topocentric position of a Uranus moon Lagrange point. Uses DE for Uranus’s heliocentric position and GUST86 theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

uranus_moon_lagrange_observe_de(body_id int4, point_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
body_id	int4	0=Miranda, 1=Ariel, 2=Umbriel, 3=Titania, 4=Oberon
point_id	int4	Lagrange point (1-5, L1 through L5)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

---

uranus_moon_lagrange_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Uranus moon Lagrange point. Uses DE for Uranus’s heliocentric position and GUST86 theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

uranus_moon_lagrange_equatorial_de(body_id int4, point_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
body_id	int4	0=Miranda, 1=Ariel, 2=Umbriel, 3=Titania, 4=Oberon
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

---

mars_moon_lagrange_observe_de

Computes the topocentric position of a Mars moon Lagrange point. Uses DE for Mars’s heliocentric position and MarsSat theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

mars_moon_lagrange_observe_de(body_id int4, point_id int4, obs observer, t timestamptz) → topocentric

Parameters

Parameter	Type	Description
body_id	int4	0=Phobos, 1=Deimos
point_id	int4	Lagrange point (1-5, L1 through L5)
obs	observer	Observer location on Earth
t	timestamptz	Observation time

Returns

A topocentric with azimuth, elevation, range (km), and range rate (km/s).

---

mars_moon_lagrange_equatorial_de

Computes the geocentric equatorial coordinates (RA/Dec) of a Mars moon Lagrange point. Uses DE for Mars’s heliocentric position and MarsSat theory for the moon’s offset. Falls back to VSOP87 if DE is unavailable.

Signature

mars_moon_lagrange_equatorial_de(body_id int4, point_id int4, t timestamptz) → equatorial

Parameters

Parameter	Type	Description
body_id	int4	0=Phobos, 1=Deimos
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

An equatorial with RA (hours), Dec (degrees), and distance (km) from Earth’s center.

Example

SELECT round(eq_ra(mars_moon_lagrange_equatorial_de(0, 4, now()))::numeric, 4) AS phobos_l4_ra;

---

hill_radius_de

Computes the Hill sphere radius in AU for a planet using DE ephemeris for the instantaneous heliocentric distance. Falls back to VSOP87 if DE is unavailable.

Signature

hill_radius_de(body_id int4, t timestamptz) → float8

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
t	timestamptz	Evaluation time

Returns

Hill sphere radius in AU.

Example

SELECT round(hill_radius_de(5, now())::numeric, 4) AS jupiter_hill_de;

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lagrange_zone_radius_de

Computes the effective zone radius around a Lagrange point using DE ephemeris for the planet’s instantaneous heliocentric distance. Falls back to VSOP87 if DE is unavailable.

Signature

lagrange_zone_radius_de(body_id int4, point_id int4, t timestamptz) → float8

Parameters

Parameter	Type	Description
body_id	int4	Planet identifier (1-8, Mercury through Neptune)
point_id	int4	Lagrange point (1-5, L1 through L5)
t	timestamptz	Evaluation time

Returns

Zone radius in AU.

Example

SELECT round(lagrange_zone_radius_de(5, 4, now())::numeric, 4) AS jup_l4_zone_de;