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MAY 2008 VIEWING LIST
Object
Type
14” Scopes
Saturn
M101*
M108**
M65**
M66**
NGC3628**
NGC4565*
NGC4656
M64**
M53*
M3
M5
(See Notes)
Gal
Gal
Gal
Gal
Gal
Gal
Gal
Gal
GC
GC
GC
Size
22’
9’
8’
8’
14’
16’
19
9’
13’
18’
12’
4” Refractor
Iota Cancri
DS
Cor Caroli
DS
Y Canum Venaticorum Carbon Star
Distance
Coordinates
LY
LY
LY
LY
LY
LY
LY
LY
LY
LY
LY
14h 03’
11h 12’
11h 19’
11h 20’
11h 20’
12h 36’
12h 44’
12h 57’
13h 13’
13h 42’
15h 19’
+54 21’
+55 40’
+13 05’
+12 59’
+13 36’
+25 59’
+32 10’
+21 41’
+18 10’
+28 23’
+02 06’
300 LY
110 LY
711 LY
08h 47’
12h 56’
12h 45’
+28 46’
+38 19’
+4526’
27,000,000
45,000,000
35,000,000
35,000,000
35,000,000
32,000,000
23,500,000
19,000,000
58,000
34,000
25,000
Abbreviations:
MS = Multiple Star, EN = Emission Nebula, RN = Reflection Nebula, Gal = Galaxy, GC = Globular
Cluster, LY = Light Year, OC = Open cluster, PN = Planetary Nebula, SR = Supernova Remnant,
CS = Carbon Star, * = Video imaging optional, ** = Video imaging recommended
MAY 2008 OBJECT DESCRIPTIONS
Saturn is guaranteed to be the most exciting object in the late spring and early summer sky. It is important to have some
interesting stats for the public as they observe this planet. See the last page of the Object Descriptions for relevant facts.
We are currently moving apart from our closest point in February.
M101 is an 8th magnitude type Sc Grand Design spiral galaxy in the constellation Ursa Major (URR-suh MAY-jer). Seen
in plan view, M101 is one of the most prominent spirals. Discovered by Pierre Mechain in 1781, M101 has an estimated
diameter of over 170,000 light years. While nearly the apparent diameter of the moon, this galaxy is fairly faint, requiring
dark skies for a quality view.
M108 is an 11th magnitude type Sc spiral galaxy in the constellation Ursa Major (URR-suh-MAY-jer). Seen at an angle,
the cigar-shaped object displays a disorderly collection of light and dark patches and the apparent absence of a defined
galactic core. This is more apparent when viewed at higher magnification.
M65 is a type Sa spiral galaxy in the constellation Leo (LEE-oh). Seen nearly edge-on, it displays a bright central core
and a faint oval corona that provides a hint of spiral arms. First listed by Charles Messier in 1780, M65 forms a fairly close
grouping with M66 and NGC 3628, described below.
M66 is a type Sb spiral galaxy in the constellation Leo that displays a more open aspect to the viewer. The Sb designation
indicates a prominent central bulge. Due to a probable close encounter with M65 in the past, M66 offers hints of a spiral
arm extending away from the core, suggesting a faint tail.
NGC 3628 is yet another spiral galaxy in Leo. Discovered by William Herschel in 1784, this type Sc edge-on spiral
exhibits a prominent dark dust band intersecting the bright core.
NGC4565 , also known as Caldwell 38, is a large type Sb spiral galaxy found in the constellation Coma Berenices
(KOH-mah bera-NEE-seez), Berenices Hair. At a relatively bright 9.6 magnitude, this is a truly outstanding example of a
spiral galaxy seen edge-on. The narrow disk and bright central core are bisected by a prominent dark lane of dust. This
galaxy is about 150,000 light years in diameter and has a total mass of 200 billion suns.
NGC4656 is a type SBm barred spiral galaxy in the constellation Canes Venatici (KAY-neez- vë-NAT-ih-si). Popularly
known as the Hockey Stick Galaxy, the key features are the angled tilt of the disk and the apparent offset of the core.
If observing at low magnification look in the same field of view for NGC4631, a more distant galaxy also seen edge-on.
M64 is a type Sb spiral galaxy in the constellation Coma Berenices (KOH-mah bera-NEE-seez,). Popularly known as the
Black Eye Galaxy, this object has a diameter of about 51,000 LY. Steady seeing will offer viewers a bright irregular shape
with uneven brightness and texture. This is as a result of an unusual characteristic: the central portion of the galaxy is
thought to rotate in one direction out to approximately 3,000 light years, while the outer portion of the galaxy rotates in the
opposite direction! Where the two countra-rotating sections meet, the interacting dust and gas creates large areas of new
star formation, seen as brighter areas. How did this happen? It is probably the odd outcome of the collision of two galaxies
in the distant past.
M53 is a globular cluster in the constellation Coma Berenices )KOH-mah-bera-NEE=seez). It is about 220 light years in
diameter. With a combined magnitude of 7.6, it is a very compressed cluster with a slightly oval shape. While M53 orbits
the Milky Way galaxy at about 60,000 light years from the galactic core, it is currently about 58,000 light years from Earth
and is approaching us at 112 kilometers per second.
M3 is an impressive globular cluster in the constellation Canes Venatici (KAY-neez vě-NAT-ih-si). Spanning 180 – 200
light years in diameter, this outstanding globular contains nearly 500,000 stars. Globular clusters are home to some of the
oldest stars in the universe. Unlike most globulars, M3 contains a large population of variable stars. At low magnification,
look for a hint of color in both the inner core and outer perimeter.
M5 is a globular cluster in the constellation Serpens (SIR-penz, the serpent). Discovered by Gottfried Kirch in 1702, this
5.6 magnitude conglomeration of stars is about 13 billion years old and is approximately 165 light years in diameter.
Observers may detect a distinct elliptical elongation to the main body of stars. Of interest is that red shift studies indicate
that M5 is currently receding from us at about 30 miles per second in its path around the Milky Way.
Iota () Cancri is a beautiful double star in the constellation Cancer (CAN-sir). Rivalling Albireo with it’s striking pair of
orange and blue stars, this pair gleams at 4.1 & 6.0 magnitudes. With a separation of 31” of arc, this pair is best seen
using the 4” refractor at low magnification. Observe Iota Cancri before it sets too low in the west.
Cor Caroli, or  Canum Venaticorum, is the brightest star in the constellation Canes Venatici (KAY-neez vě-NAT-ih-si). It
is also an attractive double star for small scopes. With stellar magnitudes of 2.9 & 5.6, look for a blue-white primary and a
dimmer yellow-white secondary. Try the 22mm eyepiece on the 4” refractor for the best view.
Y Canum Venaticorum is a J class variable carbon star in the constellation Canes Venatici (KAY-neez vě-NAT-ih-si)
that displays an unusual abundance of the carbon-13 isotope. The red color is caused by large amounts of carbon
molecules such as carbon monoxide and cyanogen, in the star's outer layers. Absorption of shorter wavelengths of light
by these molecules results in its intense reddish hue.
SATURN FACTS
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Sixth planet from the Sun.
Second largest planet in the solar system.
Average distance from the Sun – 900 million miles
Current distance from Earth – 800+ million miles
Diameter is approximately 65,000 miles at the poles, and 72,000 miles at the equator. Why the difference?
Average rotation period is 10 – 11 hours.
Orbital period around the Sun is 29.5 years.
Saturn has had observed wind speeds as high as 1100 miles per hour. Four times faster than wind speeds on
Jupiter.
The density of Saturn is only 0.7 grams/cubic centimeter. Less than water. The planet would float in water.
An interesting fact is that Saturn radiates more heat than it receives from the Sun. Scientists speculate on why.
Edge-to-edge diameter of the main ring system is over 180,000 miles
Average ring thickness is only about 1 kilometer (3,000 feet). Range is from roughly 200 meters to 3000 meters.
Number of major rings – 5. Thousands of minor rings
Dark ring visible is the Cassini Division, a gap in the rings caused by the gravitational influence of small moons
within the ring structure.
34 named moons. Largest is Titan, second largest moon in the solar system. At 3200 miles in diameter, Titan is
larger than Mercury.
F. Lockhart