Download Constellations - Sierra Star Gazers

SIERRA STAR GAZERS
Observations for the July 22nd & 29th, 2011 Star Party
SSG Coordinators will be at the Ice House Observing Park observing site on July 22nd
and Magnolia Trailhead on the 29th at 8:00 pm to assist observers with basic
telescope setup procedures, Newtonian mirror collimation, and polar alignment
questions. IHOP is an excellent high altitude venue for quality observing, however,
dress warmly even in July, and walk carefully. The surface is a bit rough. Why go there?
Because it normally has a very dark and stable sky.
For directions to the Ice House Observing Park, just refer to page 4 of this list.
Please turn off your headlights, park your vehicle and set up your instruments as
directed.
Over the years the SSG Coordinators have made (and survived) just about every setup
and observing error possible, so don’t be afraid to ask questions.
Remember, if you are fortunate to have more than one eyepiece, always begin
observing each object with the least magnification possible.
If you don’t have a telescope at this time, come join us anyway. We enjoy sharing.
July brings warm (and hopefully DRY) days with frequently cool evenings that can result
in great observing. Even so, experienced observers dress in layers and ALWAYS wear
a warm hat, preferably one that can cover the ears. A thermos of a hot beverage and
some munchies are guaranteed to make your innards toasty and your time at the
eyepiece more memorable. A bottle of DEET is always welcome for combatting flying
vermin.
July 22nd will be our first high altitude observing session for the season. Even if you
are new to astronomy, don’t let worries about the trip to IHOP scare you off. You will be
less than an hour from Placerville, & Starbucks is open late. 
The observing program for both evenings will begin by making some of our last SSG
Group observations of Saturn. Then we will move on for a survey of some of the great
deep sky objects found in the southern summer sky. The descriptions of some objects
may include apparent size in minutes of arc (‘). For comparison, the full Moon is 30
minutes of arc, or 1/2.
SSG Lead Host – Forrest Lockhart
Constellations
Tonight we’ll be observing objects in the southern constellations of Scorpius,
Sagittarius, Scutum, and Serpens Cauda. While the emission nebulae we have targeted
benefit from the use of OIII or dark sky filters, these objects are also quite nice without
them. So go for it!
For the adventurous this evening, turn to our new Challenge Object on the last page
of this list. If you find the object, you will have earned bragging rights. 
Scorpius
(S&T Pocket Sky Atlas – pgs 56 & 58 )
This constellation is best located by looking southward to the familiar scorpion shape,
then locating the bright red star, Antares. This red supergiant represents the heart of the
easy-to-recognize scorpion.
Messier 4 is a 5th magnitude globular cluster that may be seen in the same FoV
with Antares at low magnification. M4 is 6800 light years distant, and has an
apparent diameter of 35’ in photos. The actual diameter of M4 is 70 light years.
This globular takes magnification well, so increase power and look for indications
of a bright central bar extending across the disk, which accounts for the oft
mentioned moniker, the Cat’s Eye.
Messier 80 is another globular cluster, shining at magnitude 7.3. M80 is located
27,000 light years away, which accounts for it’s small apparent diameter of only
9’. What it lacks in apparent size, it certainly makes up in stellar density. Find
M80 by moving about 4.5° northwest of Antares. Star-hoppers can draw an
imaginary line from Antares to the star Graffias, Beta (β) Scorpii. M80 is nearly
halfway between the two stars.
Sagittarius
(S&T Pocket Sky Atlas – pg 67)
This constellation is easily found just east of the scorpion’s stinger. While Mythology
identifies it as an archer, we see it as an obvious teapot with steam (the Milky Way)
drifting upward from the spout.
Messier 22 is yet another 5th magnitude globular cluster, but what a cluster! Over
500,000 stars make up this teeming conglomeration of lights that extends across
about 33’ of sky. Situated only 10,000 light years away, M22 is one of the nearest
globulars to us. Look just to the left of the top star in the teapot lid (Kaus
Borealis) and there it is. In his work, The Hobbit, J.R.R. Tolkien described M22
as, “if a globe had been filled with moonlight and hung before them in a net
woven of the glint of frosty stars.” ‘nough said, say I. Find it and enjoy!
Messier 28 is another globular cluster, glowing at magnitude 7, about 20,000
light years away, which accounts for its apparent diameter of only 10’. You will
find it just above, and slightly to the right of, Kaus Borealis. Use about 70x to
obtain an overall picture of M28, then increase magnification to 120x or more to
inspect the inner region. Some observers have reported a faint peach hue to the
core at high powers. What do you see?
Messier 8 is a combination of an open star cluster and a bright, magnitude 4.6,
emission nebula located about 5,200 light years away. Visible to the unaided
eye, M8 resides in the vapor seen rising from the Teapot’s spout. Commonly
known as the Lagoon Nebula, M8 displays apparent dark channels that weave
throughout the glowing gas. Since the nebula extends over one degree in
apparent size, use the lowest magnification you have available for the best view
of this fascinating object. OIII and Deep Sky filters work well on the Lagoon.
Messier 20 is another bright cluster/nebula combination, and is very near to M8
in the sky. In fact it is somewhat nearer to us, at a distance of 5,000 light years.
M20 is considerably smaller than the Lagoon. Look for an object about 20’ in
extent. In my 4” scope at 23x, I can view both M8 and M20 in the same field of
view. Commonly known as the Trifid Nebula, close inspection will reveal several
dark lanes that roughly split the glowing cloud into three major (some say four)
portions. As with M8, OIII and Deep Sky filters work well here.
Messier 17 is my favorite emission nebula in Sagittarius. Commonly known
variously as the Omega, Swan, or Horseshoe Nebula, resides about 4,900 light
years away. M17 is a relatively large object at 40’, with a combined magnitude of
6, and is generally found by trolling up the Milky Way steam cloud from M20 until
you find it. M17 is my favorite because new observers tend to see it differently.
My first impression was of a glowing checkmark, while others may see an
obvious swan. Much depends on the size of scope you are using, so take time to
wander about for peeks through your neighbor’s scopes. Most deep sky filters
work well on M17.
For an extra challenge in Sagittarius, look closely at the lower portion of page 67 in your
atlas. The bottom of the teapot holds three faint globular clusters, Messier 54, 70, and
69. If you find them, let us know.
Scutum
(S&T Pocket Sky Atlas – pg 67)
This constellation is in a relatively bright star-poor region, but holds one of the finest
open clusters in the heavens. While some observers consider open clusters as a bit hohum, I guarantee that this one will get your attention.
Messier 11 , commonly known as the Wild Duck Cluster, is a magnificent
collection of about 400 stars shining above 14th magnitude. Found at the
northernmost border of Scutum and Aquila, M11, with a magnitude of 5.8, is
frequently visible to the unaided eye. Situated 5,460 light years from the Sun,
M11 is about 13’ in diameter. At low power, the cluster stars take on an apparent
fan shape seemingly radiating from a warm yellow star. While this star seems to
be a true member of the cluster, in fact it is not.
Serpens Cauda
(S&T Pocket Sky Atlas – pg 67)
This constellation resides directly above the teapot and holds one of the finest emission
nebulae in the sky.
Messier 16 is yet another open cluster/emission nebula which glows at 6th
magnitude. Commonly known as the Eagle Nebula, it is located about 9,000 light
years away. Viewed with my scope at low magnification, M16 appears in the
shape of a flying bird as seen from above. Diligent observing may reward you
with the sight of dark columns and stygian wedges on the perimeter of the
nebula. At the observatory you can view the famous Pillars of Creation in the
central area, but alas, unless you possess a very large scope……
Planetary Observing
Saturn is still found in the constellation Virgo, currently drifting toward the western
horizon. Saturn’s rings are now tilted to highlight the famous Cassini Division. A close
look may disclose one of the white storm clouds that have been observed lately. Saturn
is always an attention-getter and is worth some quality eyepiece time. Observe it before
it drifts into the twilight
Ice House Observing Park Dark Sky Site
The IHOP observing site is in a remote region above Highway 50. Most observers agree
that this mountain ridge is generally blessed with excellent seeing, but is best done in a
group. At both of the most used IHOP sites, things are frequently heard to slither, creep,
and go bump in the night. 
Things to bring: Cold weather gear even during the summer months, and a stout lawn
rake to clear a smooth pad for your scope and chairs.
Directions to IHOP2: Drive east on Highway 50 into the mountains. Exit Highway 50
onto Icehouse Road. Travel about 6.3 miles to Peavine Road at the crest of the ridge.
Turn left and drive about 0.5 miles to an open lot on the left. There is an old abandoned
road department shed at the east end of the lot. Carefully drive to the south side of the
lot and park in an area most free of rocks.
Magnolia Ranch Trailhead
This site is on Highway 49, between the towns of Lotus and Pilot Hill. If coming from
Highway 80, just drive 1.7 miles past Pedro Hill Road and look for the turnoff on the
right.
If coming from Highway 50, look for the trailhead sign 3.6 miles west of the Tintersection of Hwy 49 and Lotus Road.
Forrest Lockhart
SSG Coordinator
Challenge Object
This month’s challenge object is the Bridal Veil Nebula in Cygnus. This extended object
is also known as the Cygnus Loop. Composed of NGC 6960, 6992 and 6995, this large
collection of nebulosity is the result of a supernova explosion about 2,500 light years
distant that occurred some 15,000 years ago.
This type II supernova marked the final chapter in the life of a supergiant star with an
original mass at least eight times that of our Sun. As the fusion process eventually
progressed to the element, Iron, all fusion stopped, gravity took over, and in seconds,
the star collapsed into a sphere approximately 10 km across. The blast destroyed the
star and spewed its remains outward into deep space at a velocity of several thousand
kilometers per second. The long streamers of nebulosity we see today are remnants of
the still-expanding shell that are now colliding with clouds of interstellar gas, The
resulting shock wave is primarily responsible for the emission nebulae we see today.
Some observers have never seen the Cygnus Loop and feel that it is too difficult for
their scope, but if you have an 80mm refractor, a 4.5” reflector, or anything larger, you
can capture the Loop. The primary requirement for a quality look is a wide field of view,
which actually favors the smaller scopes. Page 62 of Sky and Telescope’s Pocket Atlas,
will be a great asset in reaching your targets.
Begin your search by inserting your lowest magnification eyepiece, then locate the star
Sadr, Gamma (γ) Cygni, which is the heart star of the swan. Now move eastward to the
first star in the wing, Epsilon (ε) Cygni. Now move slightly southward to 52 Cygni. This
star seems to be immersed in the beautiful swath of glowing gas known as NGC 6960.
I’ve found that the easiest method for finding the other remnants is to imagine the
arched shape of NGC 6960 as a partial ring of water resulting from a pebble tossed into
a pool, then imagine the direction to the center of the ring. Now move your scope in that
direction until you encounter the more extensive, intertwined arcs of NGC 6992 and
6995. Along the way, slightly to the north, you will no doubt encounter a triangular gas
cloud known as Pickering’s Wedge.
My first encounter with this amazing group of nebulae was through an unfiltered 85mm
refractor under a dark sky, and I was immediately hooked. If you have access to a Deep
Sky or OIII filter, use it, but no filter is required to enjoy the magnificent remnants of that
stellar death so long ago. When you find it, call out so we can share the view.
Forrest Lockhart