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Astronomy Today, Chaisson & McMillan, 6th Ed.
1. When was this text published? 2008
2. Where did the authors earn their degrees? Harvard & Cambridge
3. What constellation is depicted at the bottom of page 1, and what EM band is it
photographed in? Pleiades, optical (visible)
4. What pages are the Star Charts found on? S-1 through S-9
5. What are the three common temperature scales? Fahrenheit, Celsius, Kelvin
6. Which scale is used most in astronomy? Kelvin
7. There are two asteroids shown on p 362. How can you tell which one is bigger?
By referring to the length scale at the bottom left of each image. Which
one is bigger? Ida
8. Almost every photo in the book has a small strip under it that has a wavy line
and the letters
R I V U X G. What do these letters stand for, and what is
this strip used for? Radio, infrared, visible, ultraviolet, x-ray, gamma.
Tells you what band of the EM spectrum the image was created with.
What letters could you add to the strip – and where -- if you wanted to be
thorough? You could add “M” for microwaves between the I and the R.
9. What is the Geocentric Theory of the universe and who come up with it? How
does it differ from the Heliocentric Theory? Ptolemy came up with
Geocentrism, which says the earth is at the center of the solar system.
Heliocentrism says the sun is the center.
10.
Which planets show retrograde motion, and why? Any planet that is
farther away from the sun than the earth will, from the earth, appear to
move backwards as the faster-orbiting earth “passes it on the inside.”
11.
What does a Hertzsprung-Russell diagram show? Who is it named after?
H-R diagrams show the ratio of a star’s luminosity to its temperature,
and was created by Ejnar Hertzsprung and Henry N Russell.
12.
What do the letters O B A F G K M on an H-R diagram stand for?
This is the Harvard system for spectral classification (i.e. temp & color,
The modern Morgan-Keegan system adds L, T & Y after M). The letters are
ordered strangely because they are relics from a late-1800s system that sorted
stars by number of spectral lines. That system was alphabetical, A-Q. In 1901
stars were re-sorted by color/temp (they are connected) scrambling the letters.
The Sun is a G2v (“2” indicates a 1-10 rank within a letter – an A4 is slightly
hotter than an A5 star -- and “v” refers to whether a star is a white dwarf, red
giant, main sequence, etc.)
13.
What are the two main types of planets in our Solar System? Terrestrial
(rocky, solid surface, you could stand on them) and Jovian gas giants
(spherical clouds with liquid – and occasionally solid--cores)
14.
Name the planets that belong to each type.
T = Mercury, Venus, Earth & Mars
J = Jupiter Saturn, Uranus & Neptune
15.
What is the more important dimension of a telescope, its length or its
diameter? Why? Diameter determines how much light enters the telescope.
16.
How many chapters are in this textbook? How many Appendices? 28, 3
17.
Use an appendix to find the length of a light year. White this length with
regular numerals.
9.46 x 1015m.
9,460,000,000,000,000m
18.
Use an appendix to find what the letters A.U. stand for. Astronomical
Unit (sun – earth distance) 150 million km
19.
How many moons does Mars have, and what are their names? 2. Phobos
& Deimos
20.
What are Jupiter’s four largest moons? Are they larger or smaller than
our Moon?
Ganymede, Io, and Callisto are lager. Europa is slightly smaller.
21.
What is the difference between perigee and apogee? Apogee is when
the moon is farthest away from the earth in its elliptical orbit. Perigee is
when it is nearest.
22.
How does a sidereal day differ from a solar day. Sidereal day is longer
by 4 minutes, because a sidereal day is one rotation in relation to the
STARS. [Since we go around the sun, the sun appears to move a little against
the star background every day.
23.
What is Right Ascension/Declination? Angular distance away from
the celestial prime meridian.
24.
Sirius is the brightest star in the sky after the Sun, but it’s not the closest
to the sun. Use an Appendix to list the stars that are closer to the Earth than
Sirius. There are six, seven if you count the Sun….
- Sol (8.3 light minutes)
- Proxima Centauri (4.2 LY)
- Alpha Centauri (4.4 LY)
- Barnard’s Star (5.9 LY)
- Wolf 359 (7.8 LY)
- Lalande 21185 (8.2 LY)
- UV Ceti (8.4 LY)
- Sirius (8.6 LY)
25.
Compare the following: asteroid belt, Oort cloud, Kuiper belt.
Asteroid belt and Kuiper belt are VERY similar. The two “belts”
generally have predominantly rocky objects, The Oort Comet Cloud (as it
is sometimes called, to reduce confusion) has icy objects.
The Asteroid Belt is between the orbits of Jupiter and Mars;
The Kuiper Belt exists beyond Neptune’s orbit, and the Oort cloud
(hypothetically) exists WELL beyond that, out to about ¼ the distance to
Proxima Centauri [it represents the practical boundary of both the solar
system and the sun’s influence.]
26.
How can you use the Big Dipper to find the North Star? (What is this
star’s name?)
Pointers….
27.
How many arc minutes are in a degree?
60 arc minutes in 1 degree, 60 arc sec in 1 arc minute = 3600 arc seconds
in a degree (REMEMBER: sun & moon are half a degree in diameter)
28.
Why do the sun and stars rise in the east and set in the west?
East is the direction the earth rotates so diurnal motion (fancy name for
stuff moving across the sky as earth turns) is: rising in east, setting in
west. (NOTE: East is the defining direction on any rotating body, NOT north!
East is the direction of sunrise, all other directions are relative to that.)
29.
Using the chart on p. 152, would you say the Earth is Terrestrial or
Jovian?
You’d better say terrestrial! Earth is (relatively) close to the sun, is
relatively close to mars & Venus, has (relatively) small mass and small radius,
has a predominantly solid, rocky surface crust, has high density (at 5g/cm3, 5x
density of water, earth is the densest planet), has weak magnetosphere, few
moons and no rings.
30.
Using the graph on p. 243, at what altitude above the surface of Venus
(km) is Venus’s atmosphere the most “earthlike?” Room temp in Kelvins is
295, so somewhere around 50 km up. (Hey! Could we build floating space
stations an colonize Venus’s atmosphere? Never say never, but with H2SO4
as prevalent in Venus’s atmosphere as H2O is in earth’s, it’s not likely!)
31.
At which Lagrangian point would be the best place to park an infrared
telescope? (Hint, it would need to be as cold as possible since infrared is
essentially heat, and any heat thrown off by the scope itself would mess up
what you were observing. Putting an infrared scope in sunlight would be as
unthinkable as building a visible light scope and molding its tube out of glowin-the-dark plastic!) Which Lagrange point is forever in the sun’s shadow?
Earth-Sun L2. The other 5 points are bathed in direct sunlight!
32.
What materials make up most of the sun, Jupiter and Saturn?
H , He
33.
What is the difference between a meteor, a meteoroid, and a meteorite?
ALL ARE SPACE ROCKS:
Meteoroids hurtle through empty space
Meteors have encountered earth’s atmosphere and are glowing (i.e. they’re
shooting stars)
Meteorites have landed.
34.
The moon has a synchronous orbit around the earth. What does that
mean?
It rotates once per orbit SO the same side of the moon faces earth
constantly. Almost all moons in the solar system have synchronous orbits
around their primaries. (NOTE: Do not confuse synchronous with
GEOsynchronous (aka geostationary) orbits! This is an orbit where a
satellite’s orbit is over its primary’s equator AND matches the primary’s
rotation period! Only man-made satellites do this!  It’s why your TV
satellite dish only ever points to one spot in the sky, but it is trained on an
orbiting communication satellite.