PH 109 Astronomy Test 1

How does the altitude of the north celestial pole relate to the observer's geographic latitude on the surface of the Earth?

The altitude of the NCP is equal to the observer's geographic latitude.

The Sun is the brightest object in the sky visible from Earth. What is the apparent magnitude of the Sun?

-26.9

What is the declination of an object that lies equidistant between the celestial equator and the south celestial pole?

-45 degrees

What is the absolute magnitude of the star Deneb?

-8.75

What is the declination of an object that lies directly on the celestial equator?

0 degrees

What is the right ascension of an object exactly on the vernal equinox?

00h 00m 00s 1st choice 14 h 24 m 24 s 2nd choice

How much brighter is the planet Venus than the planet Mars on January 24, 2015?

109 times brighter

What is the rate of the Sun's diurnal motion across the sky?

15 degrees per hour

Zoom in on the star Regulus. What are the approximate coordinates of Regulus as shown in the Main Window for this specific date and at this specific time?

Altitude = 17° Azimuth = 90°

At what time of the day is the Sun most likely to be at its highest altitude, on the local meridian?

At noon

Over what time period is the Sun actually in the constellation of Sagittarius?

December 19 to January 20

The Sun, Moon, planets and stars rise in the ____ and set in the ____.

East, West

Is the following statement true or false? "Astrology has kept pace with our present knowledge of the changing sky".

False

What is the second brightest object in the sky?

Full moon

Which of the following statements is NOT true?

Gemini crosses the meridian in December and Virgo crosses the meridian in March. b. The constellations shift west slowly and return to the same position a year later. c. Aquarius appears on the meridian at midnight in late August. d. The constellations show no motion over the course of one year. CORRECT

After this time has been advanced by two hours, which of these statements is correct?

a. Regulus and the coordinate grid have both shifted westward. b. The altitude and azimuth of Regulus have changed because the local coordinate grid has shifted westward. c. The altitude and azimuth of Regulus have changed while the local coordinate grid has remained fixed. CORRECT d. The constellations have shifted westward but the local coordinates (that is, altitude and azimuth) of Regulus have not changed.

Select the statement that correctly describes how Minkar's altitude changes over time.

a. The altitude of Minkar increases continuously right across the sky as time advances. b. Minkar reaches its maximum altitude as it crosses the meridian. CORRECT c. The altitude of Minkar is greater to the west of the meridian than it is to the east of the meridian. d. The altitude of Minkar is negative to the east of the meridian, and positive to the west of the meridian.

Change the time flow rate to 1 day (solar day). Note the position of the Moon and the background stars and click the Step Time Forward button to advance time by 1 solar day. Then change the time flow rate to 1 sidereal d. (sidereal day) and watch the Moon and stars in the view when you click the Step Time Forward button again, this time to advance time by 1 sidereal day. Repeat these steps to decide which of the following statements is NOT correct.

in 1 day, the stars and the moon both appear to move in the same direction

Virgo is considered to be a spring constellation in the northern hemisphere because:

it is highest in the southern sky at midnight in springtime

Where would the celestial equator appear to be located for an observer standing directly on one of the Earth's poles? Hint: Change your location on the Earth to the North Pole.

It would be parallel to and coincident with the horizon.

Which of the following four stars from the constellation Orion is the faintest?

Mintaka

What is the distance between Antares and Han?

205.7 light years

Change the date to July 5, 2009. What is the approximate angular separation between the star Antares and the Moon?

21 degrees

An observer notices that the Sun is directly overhead at midday during the Summer Solstice. What is this observer's latitude upon the Earth?

23.5 degrees North

Right-click (Ctrl-click on a Macintosh) over the Moon in the view and select Magnify from the contextual menu that appears. Then use the Zoom buttons in the toolbar to magnify the Moon until it fills the entire main window. Read the zoom display. Roughly, what is the angular diameter of the Moon?

30 arc minutes (30')

The Moon's diameter is approximately:

30'

What is the maximum angular measure that a star at this latitude could possess in order to be considered a circumpolar star?

45 degrees

From this location in Toronto, Ontario, Canada, the angular distance between Polaris and the zenith is approximately:

47°

The angular distance between Merak and Dubhe is:

5° 22' 25"

A magnitude 2 star is ____ times brighter than a magnitude 4 star.

6.31

Place the adaptive hand cursor over the star Antares. How far away from you (the observer) is Antares?

604 Light years

The calculated diameter of mars is:

6510 km

What fraction of a circle does the difference in the Sun's altitude as measured from the two cities represent?

7/360

What is the approximate angular separation between the star Antares and the Moon?

9 degrees

What is the circumference of the Earth using Eratosthenes' method?

950 km x (360/7)

what is the orientation of the Big Dipper asterism in winter?

It sits with its handle downwards

What happens to the position of Polaris in your sky as time advances over a period of a year?

It revolves in a very small circle around the north celestial pole.

Which statement regarding celestial objects seen at the poles is false?

All stars are visible over the course of a year from the poles.

How do the coordinates of Vega in 2009 and 3009 change?

Both the RA and DEC are different

What was the best time for viewing Jupiter from Toronto, Canada on the night of July 4/5, 2009?

July 5, 2009 at about 4am daylight saving time

On what date does the Sun reach the most northerly point (the summer solstice) along the ecliptic? On what date does the Sun reach the most southerly point (the winter solstice) along the ecliptic?

June 21 and December 21

On what date of the year does the Vernal Equinox occur? On what date of the year does the Autumnal Equinox occur? [Hint: Run time forward to find the two dates when the Sun is on the celestial equator.]

March 20 and September 22

The compass direction points (N, NW, W, SW, S, SE, E, NE) are marked along the horizon in Starry Night. Change the direction you are facing until the gaze display shows an Azimuth (Az) of 315 degrees. Towards what compass direction are you facing?

NW

An observer in Earth's northern hemisphere is looking directly towards Polaris. In what direction is this observer facing?

North

What is the additional constellation through which the Sun now moves?

Ophiuchus

Which of the following is not a constellation of the zodiac?

Orion

Which of the following celestial objects is NOT always found near the constellations of the zodiac?

Pluto

The relatively bright star near the north celestial pole is:

Polaris

Locate the star Altair in the sky. What are its approximate celestial coordinates?

RA =19 h 52 m Dec = + 9° 40'

What is the nearest star to the south celestial pole, as shown in the Main Window? (Hint: Use the Search facility to locate these stars and zoom in towards the SCP. Then use the Angular Separation Tool to measure their angular distance from the SCP.)

Sigma Octantis

From your observations of the position of Vega, what can you conclude about the rising of stars from night to night?

Stars rise 4 minutes earlier each night.

The vernal equinox is presently in the constellation Pisces. In what constellation was the vernal equinox located in the year 2500 BCE?

Taurus

Why do we observe diurnal motion from the surface of the Earth?

The Earth rotates on its spin axis carrying an observer in a complete rotation from west to east once every 24 hours

What causes the slow shift of the stars and constellations from one night to the next?

The Earth's revolution around the Sun once a tear.

What effect does changing an observer's latitude have on the altitude of Antares?

The altitude of Antares increased as the observer's latitude decreased.

What is the relationship between the altitude of Polaris and the latitude of the observer?

The altitude of Polaris is almost the same as the latitude of the observer.

Consider both of your sunrise observations. What appears to be the relationship between the angle that the track of the rising Sun makes with the horizon and the latitude of the observer?

The lower the latitude, the greater the angle that the track of the rising Sun makes with the horizon.

How closely do the dates of the Sun's actual passage through Capricorn in the year 2000 BCE match with astrologers' Sun sign dates?

The two date ranges disagree by about twelve days.

When was the last time that the Sun sign positions from astrology accurately reflected the true location of the Sun in the celestial sphere?

They were accurate 2000 years ago

Which of the following constellations does the celestial equator not pass through? Hint: Click anywhere in the Main Window and press "k" on your keyboard to toggle the constellations on and off.

Ursa Major

Polaris is part of which constellation? (Hint: Select Constellations from the Settings view to display IAU Boundaries and Show Names).

Ursa Minor

Which star has the following celestial coordinates: RA = 3 h 59' Dec = -13° 28'

Zaurak

Which of the following statements is correct:

a. A star's right ascension is constant but its declination changes because of the change in latitude of the observer's location. b. Both the right ascension and declination of a star's celestial coordinates change with the observer's geographical location. c. A star's declination is constant but its right ascension changes because of the change in longitude of the observer's location. d. The celestial coordinates of a star do not change when an observer's location on the Earth changes. CORRECT

Which of the following statements is correct?

a. The nighttime side of the Earth always faces the same constellation. b. The nighttime side of the Earth faces a more westerly constellation as time progresses. c. The nighttime side of the Earth faces different parts of the sky during the year. CORRECT d. The sky rotates around the Earth.

The ecliptic is inclined at 23.5 degrees to the celestial equator. This is the result of:

the tilt of Earth's rotational axis with respect to the orbital plane of the Earth.

How closely do the dates of the Sun's passage through Leo in the year 1 CE match the dates assigned by astrologers to the Leo horoscope sign?

the two date ranges agree closely

How well do astrologer's dates agree with Starry Night's dates for the passage of the Sun through Sagittarius?

the two dates ranges disagree by about one month