Chabot College

Scott Hildreth

Astronomy Worksheet

Star & Planet Locator Explorations: Winter

"One could not pluck a flower without troubling a star." - Loren Eiselely (Anthropologist)

Set your star locator so that January 31 on the moveable wheel is opposite 8 PM on the clock. (Be certain that it is 8 PM, and not 8 AM! Look for 6 p.m. and 11 p.m. nearby.)

the zentith and polaris on the star wheela) The zenith is the point on the sky directly over your head. On the locator, it is in the exact middle of the oval blue star field, NOT at the axle of the locator. Identify the constellation that should be seen directly over your head at this time on this date. If there are more than one constellations near but not exactly at the zenith, choose the one with the brightest named star.

The constellation at the zenith tonight (8pm):

The brightest named star in this constellation, which will be close to the zenith at 8pm, is:

b) Stars on the locator are ranked by brightness according to the size of their "dot". Examine the star field for winter and identify:

- The brightest star in the sky: in the constellation .

Find and identify 5 additional bright named stars in the same area of the sky:


 Star Name

 2nd brightest star    
 3rd "    
 4th "    
 5th "    
 6th "    


Note that some of the above stars may appear "equally" bright on the star wheel, based solely on the size of their dot. Do the best you can to rank them by brightness.


c) At 8pm, where in the sky do you see the brightest star? Look at the cardinal points (NESW) at the corners of the locator, and identify the direction along the horizon this star appears:

- The brightest star will be seen in the sky at 8 pm in Winter.

d) How high in the sky is this brightest star? The zenith is 90° above your head, and the horizon is considered to extend flat away from you, at 0° (ignoring local mountains or nearby buildings). So the star you found in (b) above is at some angle between 0° (at the horizon), and 90° (straight up).

the meridian, zenith, and horizon on the star wheel

So, where will you see this brightest star at 8 PM? Estimate the angle, called altitude above the horizon (between 0° and 90°).

At 8 PM in winter, the brightest star will be about degrees above the horizon.

e) How will the winter sky change during the night? Rotate your star wheel so that the date, January 31, now appears next to midnight. Look for the same bright star found in part (b). Where is the brightest star at midnight (include compass direction along the horizon as well as an estimate of its altitude in degrees).

The star is seen in the sky, at about degrees.

f) Look at the zenith now, and identify the closest constellation:

g) Look toward the east, and identify another bright star that wasn't visible at 8 PM. This will be the brightest star you'll be seeing in Spring around 8 PM! Name the star, its constellation, and estimate its altitude:

Star Name: Constellation: Altitude: °



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