An object seen halfway between the horizon and the zenith has an altitude of 45 degrees.
An object seen due east of the observer has an azimuth of 90 degrees.
The point on the horizon that is due west has an altitude of zero and an azimuth of 270 degrees.
There are a number of ways to describe locations or positions. One of these is to describe the direction toward an object in degrees; this is the "azimuth". For objects in the sky, we must also know the angular elevation above the horizon, or "altitude angle". This is usually shortened to "altitude". By specifying the azimuth angle and altitude angle, we can describe precisely the direction of any object in the sky.
In Toronto, the azimuth of the Big Dipper varies throughout the year but is generally between 300 to 340 degrees, which means it is northwest to north-northwest. The altitude of the Big Dipper in Toronto is typically around 40 to 50 degrees above the horizon.
A star with an azimuth of 180 degrees would be due south, and an altitude of 20 degrees would place it 20 degrees above the horizon. So, the star would be in the southern part of the sky, 20 degrees above the horizon.
This is probably about the "horizon coordinate system". Or, it's sometimes called the horizontal coordinate system. The system uses "altitude" and "azimuth" as coordinates. The azimuth is normally measured from due North as zero. So, that's the "three reference points", probably. Altitude is the angular height of a star above the horizon. Azimuth is the angle of a star measured along the horizon, from the pole.
If a star's azimuth is 90 degrees, it is located directly east on the horizon. An altitude of 45 degrees means that the star is positioned halfway up in the sky, forming a right angle with the horizon. Therefore, this star would be visible in the eastern sky at an angle that is halfway between the horizon and the zenith.
The point on the horizon that is due west has an altitude of zero and an azimuth of 270 degrees.
There are a number of ways to describe locations or positions. One of these is to describe the direction toward an object in degrees; this is the "azimuth". For objects in the sky, we must also know the angular elevation above the horizon, or "altitude angle". This is usually shortened to "altitude". By specifying the azimuth angle and altitude angle, we can describe precisely the direction of any object in the sky.
In Toronto, the azimuth of the Big Dipper varies throughout the year but is generally between 300 to 340 degrees, which means it is northwest to north-northwest. The altitude of the Big Dipper in Toronto is typically around 40 to 50 degrees above the horizon.
A star with an azimuth of 180 degrees would be due south, and an altitude of 20 degrees would place it 20 degrees above the horizon. So, the star would be in the southern part of the sky, 20 degrees above the horizon.
Azimuth is the horizontal angular distance measured clockwise from true north, while altitude is the vertical angular distance above the horizon. Together, these coordinates help locate a star's position in the sky.
This is probably about the "horizon coordinate system". Or, it's sometimes called the horizontal coordinate system. The system uses "altitude" and "azimuth" as coordinates. The azimuth is normally measured from due North as zero. So, that's the "three reference points", probably. Altitude is the angular height of a star above the horizon. Azimuth is the angle of a star measured along the horizon, from the pole.
This is probably about the "horizon coordinate system". Or, it's sometimes called the horizontal coordinate system. The system uses "altitude" and "azimuth" as coordinates. The azimuth is normally measured from due North as zero. So, that's the "three reference points", probably. Altitude is the angular height of a star above the horizon. Azimuth is the angle of a star measured along the horizon, from the pole.
This is probably about the "horizon coordinate system". Or, it's sometimes called the horizontal coordinate system. The system uses "altitude" and "azimuth" as coordinates. The azimuth is normally measured from due North as zero. So, that's the "three reference points", probably. Altitude is the angular height of a star above the horizon. Azimuth is the angle of a star measured along the horizon, from the pole.
This is probably about the "horizon coordinate system". Or, it's sometimes called the horizontal coordinate system. The system uses "altitude" and "azimuth" as coordinates. The azimuth is normally measured from due North as zero. So, that's the "three reference points", probably. Altitude is the angular height of a star above the horizon. Azimuth is the angle of a star measured along the horizon, from the pole.
due south and slightly above the horizon
The azimuthal grid is a coordinate system that stays still while the stars move across it on the sky (the celestial sphere). It measures the altitude above the horizon and the azimuth (position along the horizon) of the celestial object at a particular time, for a particular place.