Hour angle - Wikipedia
The sidereal hour angle (SHA) of a body on the celestial sphere is its angular distance west of the March equinox generally measured in degrees. The SHA of a star varies by less than a minute of arc per year, due to precession , while the SHA of a planet varies significantly from night to night.
Sidereal Time - United States Navy
Sidereal time is the hour angle of the equinox. If the mean equinox is used, the result is mean sidereal time; if the true equinox is used, the result is apparent sidereal time. The hour angle...
Astronomical Times - Harvard University
The Greenwich sidereal day begins when the vernal equinox is on the Greenwich Meridian. Greenwich Mean Sidereal Time (GMST) is the hour angle of the average position of the vernal equinox, neglecting short term motions of the equinox due to nutation.
Siderial (Celestial) Time
Siderial Time equals the Hour Angle of the Vernal Equinox. If you know your siderial time, it will be equal to the right ascension of the stars on your local celestial meridian. As you can see that is very useful, since as long as you know the siderial time it tells you what stars are most visible.
Celestial Sphere - University of Illinois Urbana-Champaign
Star time, properly called sidereal time, is the hour angle of the Vernal Equinox. Because the Sun moves to the east along the ecliptic, the Sun takes longer to make a circuit of the sky on its daily path than does a star or the equinox, so the solar day is 4 minutes longer than the sidereal day.
Lecture 1: Introduction to Astronomy 250
The zero-point for right ascension is the Vernal Equinox (also called the Aries Point in the text), location on the celestial equator of sunrise on the first day of spring. The total range of right ascension is 24 hrs = 360 deg / 15 deg/hr.
Hour angle | Sidereal Time, Celestial Coordinates & Celestial ...
This angle, when expressed in hours and minutes, is the time elapsed since the celestial body’s last transit of the observer’s meridian. The hour angle can also be expressed in degrees, 15° of arc being equal to one hour.
Sidereal Time - Navipedia - European Space Agency
Figure 1: Mean and True equinox. According to the previous definitions, four classes of sidereal times are introduced: Local "Apparent" Sidereal Time (LAST)( [math]\displaystyle{ \Theta }[/math] ): is the hour angle of the "true" Aries point (from local meridian) [footnotes 5] .
Sidereal Time - sce.uhcl.edu
the local Hour Angle (LHA) of the equinox is +1h (by the definition of Hour Angle), and the Local Sidereal Time is 1h. So at any instant, Local Sidereal Time = Local Hour Angle of the vernal equinox.
safe_3_2_Hour_Angle - Faculty of Science
The vernal equinox is the point on the celestial sphere where the Sun crosses the celestial equator from south to north. The vernal equinox is currently in Pisces, but used to be in Airies. Which is why it is also known as the first point of Airies.