Final answer:
To find the latitude of the place, we subtract the co-declination of the star from 90°, resulting in a latitude of 10° south. However, we cannot calculate the hour angle of the star without additional information such as the time of observation or the star's right ascension.
Step-by-step explanation:
The question asked is to find the hour angle of a star and the latitude of the place given the following data: azimuth of the star==140°, parallax angle of the star==25°, co-declination of the star==100°. The hour angle of a star tells us how far in celestial time a star is from the local meridian, and it can be expressed as an angle or in units of time. The latitude of the place is the position north or south as measured from the Earth's equator.
To find the latitude, we use the relationship that the angle of the pole star above the horizon equals the local latitude. Since the co-declination of the star is given as 100°, the complement of this value, i.e., 90° - co-declination, provides the latitude. In this case, the latitude would be 90° - 100° = -10°, meaning it is 10° south latitude.
To calculate the hour angle, we would normally consider several astronomical relationships, including the time of observation relative to the local meridian and the right ascension of the star. However, without the time of observation or the star's right ascension, we cannot determine the hour angle from the provided data.