FOR A PUBLIC VIEWING SESSION
by Steve Coe
The members of the Saguaro Astronomy Club of Phoenix, Az.
have been very active in trying to educate the public concerning astronomy.
To this end we have held many public viewing sessions over the years.
What follows is a list of deep sky objects to show in your telescope and
some info on those objects. The list is arranged by season, starting with
The Water Carrier. This place in the sky has always been associated
with watery things. Ancient Babylonian art depicted a boy pouring
water from an urn, while Arabians saw a two-handled
RA 21hr 33min Dec -00 49 Mag 6.5 Size 13'
A globular cluster of at least 100,000 stars. About 50,000 light years
distant. The cluster is 150 light years across. At the tremendous
distance of this cluster, the Sun would be very dim at magnitude 20.7,
only visible in the largest professional telescopes.
RA 21hr 04min Dec -11 22 Mag 8.3 Size 28''X22''
A planetary nebula. Called the "Saturn Nebula" by Lord Rosse
because of extending arms or ansae which protrude from the nebula
when seen under a good, dark sky. About 3900 light years distant,
which means it is 0.5 light years across.
The flying horse. The winged steed, Bellerophon, that the hero Perseus
rode to save the maiden Andromeda.
RA 21hr 30min Dec +12 10 Mag 6.4 Size 12'
A globular cluster that contains at least half a million stars.
It is 42,000 light years distant and about 130 light years across.
Try high power, there are many beautiful star chains.
RA 22hr 37min Dec +34 25 Mag 10.4 Size 11'X4'
One of the brightest non-Messier galaxies. A large scope can show
the dust lane. It can be seen in the finder or binocs. About 50 million
light years distant. Several faint companions near.
||Epsilon (î) PEG
RA 22hr 43min Dec +30 18 Mags 3/9
A lovely colored double star. A wide pair at 81", they are easily
split in any telescope. Tap the telescope tube and the dim star appears
to swing around the brighter star. Fascinating!
The chained lady. She is a princess, the daughter of Cepheus and
Cassiopeia. Andromeda is rescued by Perseus before she can be eaten
by Cetus, the sea monster. All these people and animals are in the
RA 00hr 42min Dec +41 16 Mag 3.5 Size 178'X40'
The largest, brightest SPIRAL galaxy near the Milky Way. It is easily
naked eye from a dark site and was plotted on the star charts of
a Persian astronomer Al Sufi in 950 A.D. 2.2 million light years
distant. 150,000 light years across, about the size of the Milky
Way. This is approximately what the Milky Way would look like from
outside. Two companions nearby.
RA 23hr 56min Dec +42 33 Mag 8.6 Size 17"X14"
A very nice planetary nebula. I have always seen the color as blue
or aqua. It is about 5600 light years distant, which means it is 0.8
light years across.
||Almach Gamma AND
RA 02hr 04min Dec +42 18 Mags 2/5
Means "The Foot" in Arabic, because it is the foot of Andromeda.
A very nice double star, the members are 2 and 5 magnitude separated
by 10". I have always seen them as Bluish and Orange. About 80
light years away, so the Wright Bros. had just flown when the light
started toward Earth.
queen. The mother of Andromeda and mother in law of Perseus. She
was supposed to be very vain and was made to hang upside down over
the North Pole because of it.
RA 23hr 24min Dec +61 35 Mag 6.9 Size 13'
An excellent open star cluster. It is 3000 light years distant and
10 to 15 light years across. A nice orange star is involved and
there are several dark lanes among the stars.
|| NGC 457
RA 01hr 19min Dec +58 20 Mag 6.4 Size 13'
Another good star cluster. It includes Phi (í) CAS, a fifth
magnitude star. I have heard this called the Owl cluster because the
bright stars are like eyes of an owl with outstretched wings.
||Eta (ï) CAS
RA 00hr 49min Dec +57 54
A double star with color contrast. The stars are 4th and 7th magnitude
and separated by 10". I see the colors as light yellow and orange.
The two suns are 18 light years distant and about 68 Astronomical
Units apart (an AU is the distance from the Sun to the Earth, about
93 million miles). They take about 480 years to complete one revolution
about their center of gravity.
hero. The rescuer of Andromeda and eventually her husband. He is
pictured in the sky as holding the head of the Gorgon, the snake-haired
woman, in his hand. This place is the location of Algol, the famous
and NGC 869
RA 02hr 22min Dec +57 07 Mag 4.4 Size 60'
The Double Cluster is a unique and lovely pair of excellent star
clusters that are so close together that they will fit in one wide
field of view. The ancient Greek observer Hipparchus included it
in a scroll he wrote in 150 BC. The clusters are about 8000 light
years distant. That means that the ten brightest stars are about
60,000 times more luminous than our Sun. The Sun would be a magnitude
18 star and only visible in the very largest amateur telescopes.
RA 02hr 42min Dec +42 47 Mag 5.2 Size 35'
A nice open star cluster. It is 1500 light years distant and about
18 light years across. Easy to see in binoculars.
||Eta (ï) PER
RA 02hr 51min Dec +55 52
A color contrast double star. The stars are 4th and 8th magnitude
and separated by 28 arc seconds. They are easily split at 100X. I
have always seen them as gold and royal blue.
Charioteer. Honors Erechthonius, King of Athens, who invented the
four horse chariot.
RA 05hr 52min Dec +32 33 Mag 5.6 Size 24'
One of the best winter open clusters. Any telescope will show hundreds
of members with several bright stars and beautiful dark lanes winding
among the stars. About 4600 light years distant. There is a lovely
orange (or yellow) star near center that is NOT
a cluster member, it has a different motion than the cluster.
|| M 38
RA 05hr 29min Dec +35 50 Mag 6.4 Size 21'
A nice open cluster. Has a cruciform shape at 100X. Look for NGC 1907,
a cluster nearby in the Milky Way to the south.
Hunter. He was fatally stung by Scorpius and put in the sky in a
location opposite Scorpius, so that they are never above the horizon
at the same time.
RA 05hr 35min Dec -05 23 Mag 4 Size 66'X60'
The Great Orion Nebula was discovered only two years after Galileo
invented the telescope. About 1900 light years away. Cleopatra was
Queen of Egypt when light started its way here. Density of the gas
in this glowing nebula is a vacuum by laboratory standards, but
enough material to make 10,000 Suns. 30 light years across the nebula,
which is 20,000 Solar Systems. Stars are being born within the nebulosity
right now, our Sun hatched in such a cloud of material. Trapezium
of four stars in the center. Over 50 variable stars involved within
RA 05hr 13min Dec +02 55
Nice double star. Yellow and pale orange pair are 5th and 9th mag,
separated by 7".
RA 05hr 35min Dec -05 57
One of the best triple stars in the sky. It is about 2000 light years
away, all three stars are giants in size and luminosity. One companion
is at 11", the other is 50" away from the primary star.
I have seen this triple as white, light green and purple. Honest.
RA 05hr 55min Dec +07 24 Mag 0.7 variable
This red star usually has its' name translated "Arm of the Giant."
It varies its size over a period of about 5.7 years from 550 times
the size of the Sun to 920 times Sol. This red super giant star is
about 520 light years distant. It is one of the largest and most luminous
stars visible to the naked eye. The luminosity varies from 14,000
times the Sun to 76000 times our Sun.
Bull that Jupiter transformed into when he wished to carry off Europa,
daughter of the king of Crete. The constellation consists of two
of the best open clusters in the sky, the Hyades and the Pleiades.
RA 03hr 47min Dec +24 07 Mag 1.2 Size 100'
One of the best star clusters in the sky, M45 is named for the half
sisters of the HYADES. All had Atlas for a father. 410 light years
distant. 10 light years across. 500 member stars. 3 full moons fit
across. Many lovely chains of stars. Our Sun would be a pretty insignificant
star of 10th magnitude if at the distance of this group, so the
brightest stars all giant stars. The Japanese name of this star
cluster is Subaru and there is a representation of the cluster on
the back of every Subaru automobile.
RA 04hr 27min Dec +16 00 Mag 0.5 Size 330'
The closest star cluster to Earth is about 130 light years distant.
Aldebaran is NOT a member, just happened to be in front in the same
line of sight.
RA 05hr 35min Dec +22 01 Mag 8.4 Size 6'X4'
One of the few supernova remnants that can be viewed in a small telescope,
the Crab Nebula is one of the most studied objects in the sky. Lord
Rosse gave this object its' name when he saw filaments within the
nebula that reminded him of the claws of a crab. Chinese astronomers
saw a bright star flare up in this location in 1054 AD. That was the
light from a supernova explosion, a large star ripping itself to pieces
in an extremely violet explosion. The Crab is 6300 light years distant.
There is a white dwarf star in the center that excites the gas to
glow, just like in a neon bulb.
Twins are Castor and Pollux, represented by the two brightest stars
at the "head of the twins".
RA 06hr 08min Dec +24 20 Mag 5.1 Size 28'
A very nice open cluster. 2700 light years distant. 30 light years
across. About 300 member stars. NGC 2158 is a compact cluster 30'
SW in the Milky Way. Nice orange star near the center of the cluster.
RA 07hr 29min Dec +20 55 Mag 8.6 Size 47"X43"
One of the best planetary nebulae in the sky. It is large and bright
for this type of object. 3000 light years distant and 0.6 light
years across. Search for it at about 100X or so, you are looking
for a grey-green dot. Then switch to high power (about 200X) to
look for detail. Called the Clown Face or Eskimo nebula because
of dark features that can be glimpsed in the telescope at high power.
There is a conspicuous central star on a night with even fair seeing.
Crab. Juno sent the crab to help the Hydra while in battle with
Hercules. The muscular brute stepped on Cancer and the sea-crab
was transported to the heavens for trying his best.
RA 08hr 40min Dec +19 59 Mag 3.1 Size 95'
A large, scattered star cluster. It is named Praesepe or the Beehive.
The cluster is 525 light years distant and about 13 light years
across. So, the Black Death was getting a good grip on Europe about
the time the light began its journey to your eyes. Several nice
pairs and triples within the cluster at 100X or so.
Iota (è) CNC
RA 08hr 47min Dec +28 48
A nicely colored double star. The stars are 4th and 6th magnitude
and separated by 31". I have always seen them as gold and light
Monster. The largest constellation in the sky has represented a
variety of monsters. The most popular association is with the hundred-headed
snake that lived in the Lernaen Swamp until it was killed by Hercules.
RA 08hr 13.8min Dec -05 48 Mag 5.8 Size 42'
A large and bright open cluster. This Messier cluster was 'lost'
for many years until it was discovered that Charles Messier made
a mistake in the declination of its position when he discovered
it in 1771. The cluster is about 1600 light years distant and 20
light years across.
RA 10hr 51.6min Dec -21.3
This star varies in magnitude from 6.5 to 12 in a 533 day period.
It is amazing in the telescope because it among is the reddest stars
known. It is a carbon star, one of the rare class that shows strong
bands of carbon molecules in its' spectrum. An estimate of the distance
to this star is about 1300 light years.
Lion. This constellation represents the Nemaen Lion, who was killed
by Hercules. He then wore his skin as a symbol of his prowess in
combat. In ancient China, this represented the Yellow Dragon.
RA 10hr 19.9min Dec +19.8
This is one of the most beautiful and best observed double stars
within reach of a telescope. It is a 2.1 and 3.5 magnitude pair
that is separated by 4 arc seconds. The name of this star is Al
Geiba in Arabic, which means the Mane, its' position in the body
of the Lion. It is about 90 light years distant, which means the
stars are 90 and 30 times the brightness of our Sun.
RA 11hr 20.2min Dec +13 00 Mag 8.9 Size 9'X4'
This galaxy is the brightest in the Leo subgroup. M-66 and M-65
are both fine spiral galaxies and are about 38 million light years
distant. Another galaxy, NGC 3628 is also in a wide field of view.
Large Bear. The most famous of northern constellations, this group
represents Callisto, who was transformed into a bear by the jealous
Juno, wife of Jupiter. In Britain, it outlines Charles' Wain, the
wagon used to transport King Charles I to heaven. The Big Dipper
is the outline most easily recognized here and many of the stars
in the Big Dipper have the same path through the Milky Way that
Our Sun has. That means that the Big Dipper, Our Sun and a few other
stars scattered around the sky, form an open cluster that is gravitationally
RA 13hr 23.9min Dec +54.9
This famous double star is named Mizar, which means Girdle or Loins,
its position in the Big Bear. The first double star to be discovered,
it consists of a 2nd and 4th magnitude pair separated by 15".
It is about 88 light years distant. There is a naked eye companion,
called Alcor. Mizar and Alcor form the "Horse and Rider"
they were used as a test of vision in ancient times.
RA 9hr 55.6min Dec +69 04 Mag 8.1 Size 26'x14'
This beautiful spiral galaxy is 38 arc minutes from M-82, a bizarre
eruptive galaxy. They are about 7 million light years distant.
Hunting Dogs. The names of the two hunting dogs are Asterion (Starry)
and Chara (Dear).
Alpha Canes Venatici
RA 12hr 56.1min Dec +38.3
Cor Caroli is the name of this star and it is named for King Charles
II of England, the name means "Heart of Charles". The
components of this double system are 3rd and 5th magnitude and separated
by 20 arc seconds. At their distance of 120 light years the separation
equals 770 A.U. A.U. means Astronomical Unit, the distance between
Earth and Sun, about 93 million miles or 150 million kilometers.
Therefore, the Solar System would fit 5 times between these stars.
This has always been a lovely tinted pair in any telescope I have
owned, the colors usually seen as blue-white and green.
RA 13hr 30min Dec +47 11 Mag 8.8 Size 9'x8'
The Whirlpool Galaxy is the standard example of a spiral galaxy.
Its' picture has graced the cover of many astronomical books over
the years. Spiral structure was first thought to be examples of
other planetary systems in formation. However, in the 1920's they
were recognized as huge systems of stars like Our Milky Way.
RA 13hr 42.2min Dec +28 23 Mag 6.4 Size 6'
One of the very best globular clusters in the sky. It is about 40,000
light years distant and 220 light years across. Someone at Mt. Palomar
observatory COUNTED 45,000 stars on a plate taken there. The actual
total number of members is about one million stars.
Hair in honor of Bernice II of Egypt. She cut her "golden tresses"
as a sacrifice to Aphrodite when her king, Ptolemy III, returned
safely from battle. The court astrologer told the royal couple that
the golden locks had been transformed into a constellation and it
has been included on star maps since the incident. Ptolemy III was
king of Egypt from 246 to 221 B.C.
Coma Star Cluster
RA 12hr 25min Dec +26 00 Mag 1.8 Size 6 deg
This large scattered star grouping is best studied in a pair of
binoculars or a finderscope. The Coma star cluster is about 250
light years distant. So the British were just starting to overtax
the settlers in the colonies when the light started from the cluster
to your eye. The brightest members are 50 times as luminous as the
Sun, Old Sol would be a 9.3 magnitude star at this distance, just
visible in binoculars. There are about 80 members to the cluster.
RA 12hr 36.3min Dec +26 00 Mag 10.3 Size 15'x2'
This is the classic edge-on spiral galaxy. It's "flying saucer"
shape and dark lane make it a lovely sight, it has also yielded many
beautiful photographs. It is about 20 million light years distant
and about 90,000 light years across.
RA 12hr 35.1min Dec +18.4
A double star that I have always seen as blue and gold. It consists
of a 5th and 6th mag pair separated by 20 arc seconds.
Hero. This boisterous adventurer is the stuff of many Greek and
Roman legends, including the voyage of the Argonauts and his Twelve
Labors. He is placed in the heavens by Jupiter at his death.
RA 16hr 41.7min Dec +36 28 Mag 6 Size 16'
One of the finest objects in the heavens, M-13 is a large and bright
globular cluster. This globular was discovered by Edmond Halley
(yes, that Halley) in 1714. Messier adds it to his catalog with
the note "round nebula, contains no star". Charles Messier
could have done with a better telescope. Best estimates of the number
of cluster members are about one million. Theoretical inhabitants
of the center of the cluster would see 1000 stars with a brightness
between Venus and the Full Moon!! M-13 is about 24,000 light years
away and 160 light years across.
Scorpion that stung and killed Orion. So, Jupiter put them into
the sky 180 degrees apart, that way Orion does not see the creature
who slew him. Hawaiians see the Fish Hook of the god Maui at this
point in the sky, placed there after he used it to fish the Hawaiian
Islands up from the sea. The Chinese mark this celestial location
as the Azure Dragon.
RA 16hr 30min Dec -26.4
Antares means "Rival of Mars" because this red super giant
star is near the average brightness of Mars and because it is the
same ruddy color to the naked eye. Antares is about 10 the mass
of the Sun and at least 500 times the size of the Sun. Using 520
light years as its distance, it is 9000 times the brightness of
Old Sol. A true super giant star by any standard. The outer layers
of the star are very tenuous and would qualify as a laboratory vacuum.
There is a 7th magnitude companion that is 3" from Antares,
making it a difficult split on nights of poor seeing.
RA 16hr 23.6min Dec -26 32 Mag 5 Size 25'
A very loose globular cluster that is easily resolved in most any
telescope. Look for the curious "bar" feature of stars across
the center of the cluster. It is about 6200 light years distant. So,
the very earliest of Egyptian dynasties were being started along the
Nile when the light started its journey.
RA 17hr 40.1min Dec -32 13 Mag 4.2 Size 15'
An open cluster that is bright enough to be naked eye under fairly
dark skies. It is about 1500 light years distant and 20 light years
across. There are about 80 cluster members. Look for the delicate
chains of stars that form the "Butterfly" figure.
RA 18hr 48.2min Dec -5 51 Mag 8 Size 9'
One of the richest open clusters in the Milky Way, M-11 consists of
about 500 stars down to 14th magnitude. The Sun would be a dim 16th
magnitude star at the 5500 light year distance of this cluster. It
is about 15 light years across. R.J. Trumpler calculated that an observer
at the center would see several hundred first magnitude stars, the
brightest 40 or so would equal or exceed Venus!
LYRA--the Lyre. This stringed musical
instrument was made from a turtle shell. When played by Orpheus
it would cast a spell that charmed all the creatures of the earth.
RA 18hr 44.4min Dec +39.7
This is the famous Double-Double. A pair of binoculars or a finder
will split the wide pair. Then each of those pairs will split in the
main telescope at about 150X. The wide separation is 208", then
each tight pair is between 2 and 3 arc seconds. All four stars are
about 6th magnitude. The distance between the narrow pairs is about
165 AU, the size of the Solar System. The pairs are about 0.2 light
years from each other.
RA 18hr 53.6min Dec +33 02 Mag 9 Size 80"x60"
The Ring Nebula is one of the most studied objects in the sky. It
is certainly the best example of a planetary nebula. It is about 1500
light years away and 1/2 a light year across. The central star is
very difficult to see in amateur telescopes. It is the nucleus of
the star which ejected the material that formed the Ring itself. This
dwarf star has a surface temperature of about 100,000 degrees Kelvin,
much hotter than any normal star.
VULPECULA--The Fox. Originally
Vulpecula et Anser, the Fox and Goose, maybe the Fox ate the Goose.
RA 19hr 59.6min Dec +22 43 Mag 7.3 Size 8'x5'
The Dumbbell Nebula get its' name from the shape of this planetary
nebula. It is 900 light years distant and about 2.5 light years across.
The central star probably released the gas which glows in the Dumbbell
shape starting about 48,000 years ago. Lord Rosse used his 72"
telescope to draw 18 stars involved within the nebulosity.
399 RA 19 hr 25.4min Dec +20 11 Mag 4 Size 60'
The Coathanger is an open cluster that is large and bright. It is
easily seen in a pair of binoculars or a finderscope. There is a curved
line of stars that forms the hook of the Coathanger.
Archer. Chiron placed an archer at this location in the sky to guide
the Argonauts home after they had found the Golden Fleece.
RA 18hr 03.1min Dec -24 23 Mag 5 Size 80'x40'
The Lagoon Nebula is a famous example of a diffuse nebula. There is
a star cluster involved within the nebulosity. The name Lagoon comes
from the dark lane that protrudes into the nebula. This object is
about 4000 light years distant and 60 light years across.
RA 18hr 02.3min Dec -23 02 Mag 6.3 Size 28'
The Trifid Nebula is also named for the shape of the dark lanes that
cut in front of the nebulosity. The Lagoon and Trifid may be sections
of a vast nebulous cloud in that portion of Our Galaxy. So it is also
at about 4000 light years, it is about 20 light years across.
RA 18hr 20.8min Dec -16 11 Mag 6 Size 45'x35'
The Omega Nebula, The Swan Nebula, The Checkmark, this object has
been given several common names. It is about 5000 light years distant
and 40 light years across. The bright "Checkmark" feature
can be seen in any telescope, but use a UHC filter for the faint outer
RA 18hr 36.4min Dec-29 54 Mag 5.1 Size 24'
This is an excellent globular cluster which is about 22,000 light
years distant and at least 50 light years across. It is distinctly
oblate in shape.
RA 18hr 17min Dec -18 35 Mag 2 Size 120'x90'
The Small Sagittarius Star Cloud is an easily naked eye bright portion
of the Milky Way. It is excellent in binoculars or an RFT. There are
several dark nebulae that stand out on the North side.
Swan. Jupiter flew to visit the Queen of Sparta as a swan and then
placed the swan in the heavens to commemorate the event. This is
also the Northern Cross.
RA 21hr 32.2min Dec +48 26 Mag 5 Size 32'
A bright, scattered open cluster that is best in binoculars or an
RFT. There are about 30 members in the cluster. It is 800 light years
away and 7 light years across.
RA 19hr 44.8min Dec +50 31 Mag 8.8 Size 27"x24"
The Blinking Planetary is a striking sight. This planetary has a relatively
bright central star and that makes for a unique show. As you look
at the nebula directly the star overwhelms the nebulosity and it looks
like a fairly bright star. Move your eye and look away from this planetary
and the nebula is brightest, so the object grows in size. Looking
back and forth will produce a "blinking" effect.
RA 20hr 45.6min Dec +30 43 Mag 7 Size 70'x6'
The Veil Nebula is a supernova remnant from a stellar explosion at
least 30,000 years ago. It is about 1500 light years away and 70 light
years across. This is the western part, it involves 52 Cygni. The
UHC or O III filter works very well with this object.
RA 19hr 30.7min Dec +28.0
Alberio is one of the most famous double stars in the sky. It is easily
split in most any telescope and has beautiful blue and gold color
in most instruments. The 3rd and 5th magnitude stars are split by
a wide 34". Alberio means "The Beak" because it is
pictured as the beak of a South-flying Swan (Cygnus).