annual apparent motion
jonbeš-e sâlâne-ye padidâr
Fr.: mouvement annuel apparent
General: Open to view, visible; appearing as actual to
the eye or mind.
O.Fr. aparant, from L. apparentem, pr.p. of apparere "to appear," from ad- "to" + perere "to come forth, be visible".
Padidâr "appearing, manifest," from padid "in sight, evident, clear," from Mid.Pers. patdit, from O.Pers./Av. patiy-/paiti "toward, against, back" (cp. Skt. prati- "near, toward, against, in return," Gk. proti, pros "face to face with, toward, in addition to") + O.Pers./Av. di-/dâ(y)- "to see" (Skt. dhi- "to think"), Mod.Pers. didan "to see".
tarâmun-e padidâr, qotr-e ~
Fr.: diamètre apparent
The angular diameter of a celestial body expressed in degrees, minutes, and seconds of arc, or in radians.
Fr.: distance apparente
The angular distance between two celestial bodies (e.g. the components of a binary star system), expressed in degrees, minutes and seconds of arc.
Fr.: champ apparent
The angular diameter of the circle of light that the eye sees through an eyepiece.
Fr.: horizon apparent
The circle determined by the intersection of the heavens with a → cone whose → vertex is the → eye, and whose elements are tangent to lines of the Earth's surface. Same as → visible horizon. Assuming that there is no → atmospheric refraction, apparent horizon coincides with → geometric horizon. See also → sea horizon.
Fr.: magnitude apparente
A measure of a star's observed brightness (opposed to → absolute magnitude); symbol m. It depends on the star's → intrinsic brightness, its distance from the observer, and the amount of → interstellar absorption. The brightest star → Sirius has an apparent magnitude of -1.46, while the weakest stars visible with the naked eye in the most favorable observation conditions have magnitudes of about +6.5. The stars of magnitudes less than +23 are measured by professional observatories, whereas those of magnitudes less than +30 by a telescope such as the → Hubble Space Telescope (M.S.: SDE).
Fr.: midi vrai
The moment when the center of the Sun crosses the meridian. Same as true noon.
Fr.: position apparente
Same as → apparent position.
naheš-e padidâr, jâ-ye ~
Fr.: position apparente
1) The position on the celestial sphere at which a heavenly body
would be seen from the Earth at a particular time.
Fr.: lever apparent
The instant of time when the object is in the East and the geometric → zenith distance is equal to 90° plus the → horizontal refraction plus the semidiameter minus the → parallax.
Fr.: coucher apparent
The instant of time when the object is in the West and the geometric → zenith distance is equal to 90° plus the → horizontal refraction plus the semidiameter minus the → parallax.
apparent sidereal day
ruz-e axtari-ye padidâr
Fr.: jour sidéral apparent
The time interval between two successive → upper transits of the → true equinox of date.
apparent sidereal time
zamân-e axtari-ye padidâr
Fr.: temps sidéral apparent
The → mean sidereal time corrected for the → nutation and shift in the obliquity of the ecliptic that occurs as a result of the Moon's gravitational effect. Apparent sidereal time differs from mean sidereal time in that the → true vernal equinox point is used.
apparent solar day
ruz-e xoršidi-ye padidâr
Fr.: jour solaire vrai
The duration of one rotation of the Earth on its axis (→ Earth's rotation), with respect to the → apparent Sun. It is measured by successive transits of the apparent Sun over the lower branch of a → meridian.
apparent solar time
zamân-e xoršidi-ye padidâr
Fr.: temps solaire apparent
The time based on the motion of the → apparent Sun and kept by dividing the day into 24 equal hours.
Fr.: Soleil apparent
The → true Sun as seen by an observer on Earth. The term "apparent Sun" is used in contrast to → mean Sun, which refers to an average of the Sun's position). See also: → apparent solar time and → mean solar time.
apparent visual magnitude
borz-e didegâni-ye padidâr
Fr.: magnitude visuelle apparente
→ Apparent magnitude in the visual wavelengths, around 5600 Å. → visual magnitude.
Judging from what is apparent. As far as one knows or can see.
Greenwich Apparent Sidereal Time (GAST)
zamân-e axtari-ye padidâr-e Greenwich
Fr.: temps sidéral apparent de Greenwich
The → Greenwich Mean Sidereal Time corrected for → nutation. Therefore, it is measured with respect to the → true vernal equinox. GAST and GMST differ by the → equation of the equinoxes.
→ Greenwich Meridian; → apparent; → sidereal; → time.