explain Astronomical codes, and what they stand for?

Question

TAI: TCB: TCG: TDB: also, please let me know the other degress possible the Sun can be, on the eliptic, to the Earth other than 90 or 270 degress twice a year?

seen as referanced from earth

first of all the Sun, has a polar axis as seen from Earth, and a rotation around said axis~~question asked was other degress as seen from Earth Polar Axis, would be.

Reference, forgive my typo~~ plus terminator: please explain the meaning
please also give leap seconds?

I am not asking for 360 dgress or 90 degress, I am asking for a visual from Earth what degree the polar axis looks to be in the course of one yr... on the Solstice, it looks to be 90degrees or 270 degress..

Answer 1

TAI, TCB, TCG, and TDB are various time reference frames used in astronomy for specific purposes.

The Sun moves through the entire ecliptic over the course of one year, from zero degrees (at the March equinox) at a rate of a little less than 1 degree per day. So every degree of the ecliptic between 0 and 360 will be occupied by the Sun once per year.

A terminator is the line between sunlight and shadow on the surface of a planet or moon.

The rotation rate of Earth is very slightly irregular, due to the action of tides pushing against the continents. This causes the Earth's rotation to slow down. Leap seconds are added occasionally to keep the ultra-precise atomic clocks synchronized with the Earth's rotation.

Answer 2

You have not given any context, but it appears you are talking about various astronomical time scales. TAI is Atomic International Time and is the number of seconds since midnight, January 1, 1958, as measured by atomic clocks. TDB is TAI corrected for reletavistic effects, such that it measures the number of seconds since January 1, 1958 as observed by an observer in the center of mass of the solar system (the solar core). The corrections turned out to be wrong and it was repaced with TCB (Coordinate Barycentric Time). TCG (Coordinate Geocentric Time) is TAI corrected for relativistic effects to the extent that it measures the number of seconds since January 1, 1958 as observed by an observer in the center of mass of the Earth.

The Sun can be anywhere on the ecliptic you like. It progresses continuously around it once every year.

Answer 3

TAI is International Atomic Time
TCB: Barycentric Coordinate Time
TCG: Geocentric Coordinate Time
TDB: Barycentric Dynamic Time

The Sun appears to cycle around from 0 to 360 degrees elliptic longitude every year. It does not stay *exactly* on the elliptic, it also moves north & south of it by a tiny bit, over a 18.6 year cycle. (Actually, it is the Earth that moves, not the Sun.)

Answer 4

Hi. Interesting question. This should help. http://tycho.usno.navy.mil/systime.html
TAI is International Atomic Time
TCB is Barycentric Coordinate Time
TCG is Geocentric Coordinate Time
TBD is Barycentric Dynamical Time

I would LOVE to say I knew this but its from the web...