SIERRA COLLEGE OBSERVATIONAL ASTRONOMY

LABORATORY EXERCISE

NUMBER I.C. TITLE: Celestial Roadmaps (Fall)

DATE- PRINT NAME/S AND INITIAL BELOW: GROUP

DAY-

LOCATION

OBJECTIVE:

· To Identify Constellations in a Selected Area of Sky using the SC001 & SC002 Constellation/Star Charts

· To Make a Sketch of a Region of Sky

· To Identify Stars Using a Star Atlas (Sky Atlas 2000) or Computer (TheSKY)

· To Understand the magnitudes, spectral classes, and colors of stars

· If Needed, Review and Perform the Proper Set up of the Meade Telescope and/or prepare and observing session.

DESCRIPTION:

There exists a variety of maps and atlases of the heavens for identification of constellations, stars, and other deep sky objects listed in the ‘Blue Book’. This exercise provides an opportunity for the observer to spot stars in a given area of the sky, plot them on a small chart, and by utilizing a star atlas (such as the Sky Atlas 2000), and/or computer program known as TheSKY, positively identify these stars and distinguish them from non stellar objects such as planets or comets.

PROCEDURE/OBSERVATIONS:

1. Examine Chart ‘A’ and identify five (5) constellations. Clearly print the name of the constellations, and using a HIGHLIGHTER trace the constellation boundaries on the chart.

2. Chart ‘A’ represents constellations in regions surrounding the area indicated on Chart ‘B’. Take Chart ‘B’ outdoors and allow your eyes 10-15 minutes to dark adapt. Locate the stars already plotted on Chart ‘B’ and then carefully mark ten (10) stars you can observe onto the same chart. (These can be stars already marked on Chart B or different stars). Be careful to position them properly relative to the stars already printed on the chart.

3. After you have finished, return to the lab and locate the marked stars on your SC001 chart and read the RA and DEC coordinates. If the marked star is not on the SC001 chart, estimate its location and coordinates. Enter the results in Table 1 in the columns marked “(From Chart B’)”. Label the stars you plotted from 1 through 10.

4. Using TheSKY, positively identify the 10 stars you marked on Chart “B” and enter the RA, DEC, apparent magnitude (m) and spectral class (SC) in Table 1. Determine the color of the star based on the spectral class (SC).

TABLE 1

Plot (From SC001)

#	RA	DEC	Bayer and/or Flamsteed desig.	RA	DEC	m	SC	color
1
2
3
4
5
6
7
8
9
10

Use TheSKY or ‘SkyAtlas 2000’ to identify your plotted star’s Bayer / Flamsteed designation and RA & DEC.

Use the computer program ‘TheSky’ to find the m and SC. Use the chart below to determine the color.

SPECTRAL CLASS	COLOR
O	Blue
B	Blue
A	Blue-White
F	White
G	Yellow
K	Orange
M	Red

5. Set up Meade telescope and make ‘Blue Book’ observations as time and conditions permit. Daytime class: Create observing plan and star chart for visual and/or telescopic observations as directed by instructor.

QUESTIONS AND ANALYSIS:

1. What is the apparent magnitude of the dimmest star you observed?

2. What is the apparent magnitude of the dimmest star the eye can see?

3. What is the difference between Bayer and Flamsteed Designation?

4. What is the difference between the absolute magnitude (M) and the apparent magnitude (m)?

5. Explain any discrepancies between Chart RA/DEC and The Sky RA/DEC

6. How can a planet, asteroid, or comet be distinguished from a star or other star chart object?

7. Summarize your activities tonight in the Bluebook. Include any telescope observations you may have been able to make.

Chart “A”

Chart “B”