Download SSG Coordinators will be at the Cronan Ranch observing site at 6

SIERRA STAR GAZERS
Observations for the March 12th Star Party
SSG Coordinators will be at the Cronan Ranch observing site at 6:00 pm to assist
observers with basic telescope setup procedures, Newtonian mirror collimation, and
polar alignment questions. Cronan Ranch is an excellent low altitude venue for quality
observing while staying relatively warm, AND there is a porta-potty on site!
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.
March brings cool, dew-filled evenings that can put a damper on observing.
Experienced observers dress in layers and ALWAYS wear a warm hat, preferably one
that can cover the ears. A thermos of a hot beverage is guaranteed to make your
innards toasty and your time at the eyepiece more memorable.
The evenings observing program will begin by observing some open star clusters, then
a planetary nebula, a very challenging galaxy, and winding up the evening with Saturn
and Mars. 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 – Cindy Terpe
Constellations
Tonight we’ll be observing objects in the constellations Auriga, Taurus, Ursa Major, and
a very challenging object in Draco, plus two planets.
Auriga
(S&T Pocket Sky Atlas – pg 12)
The prominent pentagon of Auriga (awe-RYE-guh), the Charioteer, visible nearly
overhead in March, is home to three beautiful open clusters that lend themselves well to
low-magnification observing. Once the pentagon is identified, all three clusters are easy
to find. However, since all of the Auriga clusters are imbedded in the gauzy background
of the Milky Way, determining the outer limits of any of them is difficult.
Messier 36 is an open cluster in the truest sense, with about 15 brighter stars
standing out amongst a hazy glow of hundreds of dimmer stars at the limit of
visibility. About 4100 light years away, this cluster of young stars is about 12 light
years across. Look for it within the pentagon and just to the inside, and midway,
of an imaginary line between Beta () and Theta () Aurigae. At your lowest
magnification, you may be able to fit M36 and your next quarry, M38, in the same
field of view.
Messier 38 is our second open cluster of about 120 visible stars, residing about
4200 light years away. This is a much larger (15 minutes of arc) and older cluster
than M36 but the density of the cluster is much lower.
Messier 37 is our third open cluster, and this is my personal favorite. To find it,
jump across that imaginary line between Beta and Theta Aurigae to a spot about
midway along the line but just outside the pentagon. There you will encounter a
much more compressed cluster about 4400 light years away. In fact, its
appearance is similar to that of some loose globular clusters, although the
similarity ends there. The best feature of M37, however, is a 9th magnitude topaz
star that seems to reside at the heart of the cluster. As deep sky objects go, this
one is a definite keeper.
Taurus
(S&T Pocket Sky Atlas – pg 14 - 15)
Thee constellation of Taurus (TAW-rus) the bull, is marked by the prominent V asterism
capped at one point by the red giant Aldebaran. To locate our next quarry, begin at the
apex of the V, the star Gamma () Tauri, and extend an imaginary line to and through
Aldebaran. Continue outward about three lengths to the 3rd magnitude star Zeta ()
Tauri. Using a low magnification eyepiece, move slightly up in the direction of Auriga
and look for a small (6’ x 4’) faint nebulous patch, the famous Crab Nebula.
Messier 1, the Crab Nebula is a supernova remnant located about 6500 light
years away. The Crab is the tattered remains of a supernova that exploded in
1054 A.D. The explosion was so bright that Chinese astronomers observed and
recorded it in the daytime sky for over three weeks. Once found, use averted
vision to eke out as much of an impression as you can. Try nebula filters if you
have them, or check it out in a neighbors scope so equipped. Depending on sky
conditions, M1 can be a tough quarry.
Ursa Major
(S&T Pocket Sky Atlas – pg 32)
The Big Dipper asterism within the constellation Ursa Major is one of the most wellknown patterns in the sky. But the Big Bear boasts more delights than those within the
dipper. Lets go Owl hunting.
Messier 97 is a faint (mag. 9.9) planetary nebula found just below the bowl of the
dipper. At a distance of 1630 light years, this has a reputation as a difficult object
for smaller scopes, with some even claiming that at least 150mm of aperture is
required to spot it. However I have glimpsed it through a 60mm refractor one
dark night. In order to see the owl’s eyes, though, a 12” scope seems to be the
bare minimum aperture. If Ken has his 18” Dob at the session, try to sneak a
peek. Locating the spot where the Owl nests is simple enough. Draw an
imaginary line connecting the two stars, Merak () and Phecda (), forming the
bottom of the bowl. Beginning at Merak, move 1/5th the distance toward Phecda,
then drop down a bit. If you spot a long, uneven streak of light you have found
the galaxy M 108! But that isn’t our target for the evening. Move a bit further
along the line and a bit more downward to see the Owl
Draco
(S&T Pocket Sky Atlas – pg 31)
The constellation Draco (DRAY-co) the dragon is not an easy field to play in. The area
around the dragon’s tail, however, does have an interesting galaxy that rewards the
star-hopper. The brightest star due east of M81-82 is the very tip of the dragons tail.
Known as Glausar, Lamda () Draconis is our first way-point. Now draw an imaginary
line from Glausar to the next tail star, Kappa () Draconis. From Kappa, move ¼ the
distance back toward Lamda., then drop down a bit to a faint smear of light.
NGC 4236 is a barred spiral galaxy about 11.7 million light years away with a
listed magnitude of 9.6. This seems bright enough to be an easy target to spot,
but there is a problem. With an apparent size of over 18 arc minutes (The Moon
is about 30 arc minutes across) the light is spread over a fairly large patch of sky.
This means that NGC 4236 is a very tough fuzzie to spot. Featured in Sue
French’s Deep-Sky Wonders article in the April 2010 issue of Sky and Telescope
magazine, this galaxy is supposed to be a likely (albeit iffey) target for scopes of
100mm aperture and larger. One plus for us is that NGC 4236 is a so-called
starburst galaxy, so the light is unevenly spread along the major axis. I’ve never
hunted for this galaxy, and am a bit anxious about finding it. But I’m going to try.
How about you?
Planetary Observing
Mars was at planetary opposition on January 29th, however, this opposition was not
favorable for observers. While, due to the elliptical orbit of our neighboring planet, Mars
can close to less than 35 million miles on some occasions, the 2010 opposition saw
Mars approaching to a distant 61.7 million miles from earth. At that distance Mars
appeared only 14.7 seconds of arc in diameter. Factor in the bad weather this year and
Mars has been a bit of a bust. But let’s take a parting glimpse anyway.
Saturn has returned to the eastern sky, currently drifting through the constellation Virgo.
Approaching opposition on March 21st, Saturn has opened its rings a bit compared to
last year, although at opposition they will have tilted to a paltry 3. This week, however,
the rings will be tilted to a whopping (?) 4. No matter what the ring tilt is, Saturn is
always an attention-getter and is worth some quality eyepiece time.
Forrest Lockhart
SSG Coordinator