What are the three accomplishments of Hipparchus?
A Greek mathematician and astronomer, he measured the earth-moon distance accurately, founded the mathematical discipline of trigonometry, and his combinatorics work was unequalled until 1870. Hipparchus discovered the precession of the equinoxes and observed the appearance of a new star – a nova.
What was Hipparchus known for?
Hipparchus, also spelled Hipparchos, (born, Nicaea, Bithynia [now Iznik, Turkey]—died after 127 bce, Rhodes?), Greek astronomer and mathematician who made fundamental contributions to the advancement of astronomy as a mathematical science and to the foundations of trigonometry.
Which of the following did Hipparchus discover?
precession of the equinoxes
Hipparchus, (b. Nicaea, Bithynia–d. after 127 BC, Rhodes?), Greek astronomer and mathematician who discovered the precession of the equinoxes, calculated the length of the year to within 6 1/2 minutes, compiled the first known star catalog, and made an early formulation of trigonometry.
What books did Hipparchus write?
The geographical fragments of Hipparchus1869
On Sizes and Distances
Hipparchus/Books
What is the great contribution of Hipparchus in astronomy?
Hipparchus is considered the greatest ancient astronomical observer and, by some, the greatest overall astronomer of antiquity. He was the first whose quantitative and accurate models for the motion of the Sun and Moon survive.
Who discovered the precession of equinoxes?
Hipparchus
The present paper is concerned with the latter aspect, in the case of the more and more frequently quoted statement that the Babylonian astronomer Kidinnu was the discoverer of the precession of the equinoxes and that this event can be dated in 379 b. c., thus antedating Hipparchus by about two and one-half centuries.
Why did Hipparchus abandon his work?
The value for the eccentricity attributed to Hipparchus by Ptolemy is that the offset is 1⁄24 of the radius of the orbit (which is a little too large), and the direction of the apogee would be at longitude 65.5° from the vernal equinox.
How did Hipparchus measure the distance to the moon?
Hipparchus used observations from a total eclipse of the Sun to estimate the distance of the Moon from the Earth. A fraction x of the diameter of the Sun covers an angle of 0.5x in the sky (since the angular size of the Sun as viewed from the Earth is approximately 0.5 degrees, the same as that of the Moon).
Which of the following was not done by Hipparchus the great ancient astronomer?
Chapter One
| Question | Answer |
|---|---|
| Which of the following was NOT done by Hipparchus, the great ancient astronomer? | created the system of star magnitudes that we still (alas) use today |
| From horizon to opposite horizon, the sky takes up how much angular distance? | 180 degrees |
Why is the precession of the equinoxes important?
The precession of the equinoxes (sometimes simply called precession), is a movement of the celestial equator, the projection of the earth’s equator into space , with respect to the fixed stars and the ecliptic, the path of the Sun’s motion in space as viewed from the earth .
What did Hipparchus do that was so important?
Hipparchus Biography. Hipparchus was a Greek astronomer and mathematician. He is known for discovering the change in the orientation of the Earth’s axis and the axis of other planets with respect to the center of the Sun. He was also the inventor of trigonometry. He had immense in geography and was one of the most famous astronomers in ancient…
When was the first observation made by Hipparchus?
According to Ptolemy, three observations were made from 162 to 158 BC and about twenty or more of these observations were made on specific dates ranging from 147 to 127 BC. Out of these twenty or so observations made by Hipparchus, the first one was made on September 26 or 27, 147 BC on the autumnal equinox.
Why did Hipparchus believe that the Sun is a great circle?
Solar and lunar theory. Hipparchus had good reasons for believing that the Sun’s path, known as the ecliptic, is a great circle, i.e., that the plane of the ecliptic passes through the Earth’s centre. The two points at which the ecliptic and the equatorial plane intersect, known as the vernal and autumnal equinoxes,…
What kind of star catalog did Hipparchus create?
Hipparchus is also said to have created a star catalog that had names and positions assigned to each star. But the number of stars in this catalog could not be ascertained as there is very little direct evidence on it. Ptolemy’s catalog consisting of 1,022 stars is presumed to be derived from Hipparchus’s original catalog.