What is a celestial equator in astronomy?
celestial equator is the great circle in which the plane of the terrestrial Equator intersects the celestial sphere; it consequently is equidistant from the celestial poles. When the Sun lies in its plane, day and night are everywhere of equal length, a twice-per-year occurrence known…
What star is on the celestial equator?
The celestial equator intercepts the horizon at the points directly east and west anywhere on the Earth. If you joined Santa last Christmas at the north pole (90 degrees latitude), you would have seen Polaris straight overhead and the celestial equator on your horizon.
Where is the celestial equator on a star chart?
The bold, horizontal line across the center of the chart represents the celestial equator (0°). The celestial equator divides the sky into north (+) and south (-) in the same respect the equator divides the Earth into north and south. The numbers marked in degrees represent declination (DEC).
Are circumpolar stars?
Circumpolar is Latin for “around the pole”. Circumpolar stars are any stars that appear to circle around the Earth’s north or south poles. Circumpolar stars always appear in the night sky. Circumpolar stars never rise or set and are always above the horizon.
Which star is currently closest to the north celestial pole?
Presently, Polaris, the brightest star in Ursa Minor, appears close to the North Celestial Pole and therefore serves as our North Star. The North Celestial Pole (NCP) is restless and over the course of 26,000 years will describe a 47 degree arc through the sky.
How do you read a star degree?
Hold your planisphere above your head so that south is at the bottom, north is at the top, east is on the left and west is on the right. You’ll notice that east and west are reversed on the planisphere to match the view you’ll see when facing south, and the stars you see should match those on the chart.
Where can you not see the celestial equator?
The stars simply rotate in a circle around our observer. The celestial equator is on the horizon- he can only see stars in the celestial Northern Hemisphere. The celestial poles are at opposite ends of the horizon and the stars arc over head, directly East-West.
Do stars set?
Stars appear to be rising and setting, as well as the planets, Moon and the Sun. Stars that are close to the Earth’s axis of rotation—what we call the north and the south pole—rotate around the poles. If the pole’s location is far enough above the horizon, some stars never set. They just keep spinning.
Why do we always see the North Star?
Polaris, the North Star, appears stationary in the sky because it is positioned close to the line of Earth’s axis projected into space. As such, it is the only bright star whose position relative to a rotating Earth does not change. All other stars appear to move opposite to the Earth’s rotation beneath them.
What is the celestial equator?
celestial equator. n. ( Astronomy ) the great circle lying on the celestial sphere, the plane of which is perpendicular to the line joining the north and south celestial poles.
When does the sun cross the celestial equator?
The sun crosses the equator travelling northward around March 21 and going southward on Sept. 21, in celestial events known as “equinoxes” (from the Latin for “equal night,” as day and night are of roughly equivalent length on these dates.) The exact dates vary a little bit from year to year because of leap years.
What is another word for celestial equator?
Synonyms for Celestial equator: n. •celestial equator (noun) equinoctial circle, equinoctial line, equinoctial. Other synonyms: •n. astronomy, great circle.
What are the celestial equator and celestial poles?
The celestial sphere is a large sphere surrounding the earth and with it we can keep references to where celestial bodies lie in the sky. North Celestial Pole (NCP) and the South Celestial Pole (SCP) – these are just the north and south poles extended into space. Celestial Equator – The earth’s equator, but at a much greater radius.