Equinox

What is angular measure?

Angular measure is how we measure angles, using degrees or radians.

What is angular size?

Angular size refers to the apparent size of an object as seen from a specific point, measured in degrees or radians. It indicates how large an object appears in the sky compared to its actual size.

How is angular measure used?

Angular measure is used to describe the position of celestial objects in the sky, allowing astronomers to calculate their distances and sizes.

How is angular size used?

Angular size helps us find out how far celestial objects are and allows us to compare how big they look from Earth.

What is angular distance?

Angular distance measures the angle between two points in the sky from a specific location, expressed in degrees or radians, and indicates the separation between celestial objects.

How is angular distance used?

Angular distance helps determine the separation between celestial objects, aiding astronomers in navigation and observation.

What is altitude?

Altitude is the angle between an object in the sky and the observer's horizon, indicating its height above the horizon, measured in degrees.

What is azimuth?

the angle between North, measured clockwise around the observer's horizon, and a celestial body (sun, moon). It determines the direction of the celestial body.

Which direction do latitude lines go?

North-South

What do longitude lines go?

East-west

How many degrees is the Earth spinning?

360/hr = 15/hour

What is UTC time? And what does + and - mean?

London time and - means how many hours behind london and + means how many hours ahead of london

What comes first longitude or latitude?

Latitude comes first, followed by longitude.

What direction is - longitude and + longitude?

minus longitude is west and + longitude is east.

What is the max longitude?

0 at the Prime Meridian and 180 degrees at the poles

How can we use the celestial sphere?

Divide the sphere into 2 by extending earth’s equator, there’s a north & south celestial sphere - both have poles, use latitude to find stars or constellations, use angles to find how far a star is from the celestial equator

What is declination?

It goes north-south, south is negative & north is positive, we need to divide the sky into N and S, and measure angles from the celestial equator.

What is right ascension?

It goes east to west, goes by hours, every 15 degrees is 1 hour and can be broken up by hours or degrees

What is an 1 degree in arc mins?

60 arc mins and every arc min is 60 arc seconds

Where is 0 degrees in the sky?

0 degrees in the sky is found at the celestial equator, it’s the most visible thing in the sky (sun), it touches the equator in march & fall during equinoxes,

What is the measuring of how high a star is from the horizon?

Altitude

What will be above us at the north pole?

Polaris will be directly above our heads which is the zenith, both alt & lat is 90 degrees, and measuring of the altitude of the north star will tell the latitude

How many motions is earth constantly doing?

4: rotation, revolution, precession, and galactic.

What is precession?

The rotation of Earth’s axis itself and makes one rotation every 26,000 years causing the way we view stars to change

What is rotation?

The earth’s rotation on it’s own axis, which causes day & night and happens every 24 hours (23h 59m)

What is revolution?

The movement of Earth around the Sun in an elliptical path, completing one full orbit approximately every 365.25 days, which defines the length of a year.

What is a galactic year (4th motion)?

When the Earth completes one orbit around the center of the Milky Way galaxy, taking about 225-250 million years.

What is the flat plane connecting the earth & sun?

The ecliptic plane, which is the imaginary plane that extends out from the Earth's orbit around the Sun.

What does precession cause in terms of zodiacs?

As earth spins & wobbles, it’s changing orientation which causes the gravity of the sun & moon to pull the earth, it means that old zodiac signs aren’t true anymore because the shift in the position of the stars affects the alignment of the zodiac constellations with the seasons.

Why aren’t the days in each zodiac sign the same?

The days in each zodiac sign vary due to the Earth's axial tilt and orbital eccentricity, which affect the timing of the equinoxes and the position of the sun relative to the constellations throughout the year.

What is the next north star?

Vega in about 12,000 years.