Saguaro Skies Oct 2011 - Saguaro Astronomy Club 2011.pdf · September, 2011 Volume 35, Issue 7 ... also has Telrad, two 1.25 eyepieces ,and owners manual. ... The C-8 on a GEM Mount

September, 2011

Volume 35, Issue 7

Saguaro Astronomy

Club, Phoenix, AZ

The President’s Corner O.k., I'm not trying to jinx us or

anything but it's September. And we all know what happens in September - the monsoon ends. Theoretically any-way. Bring on the clear skies and cooler temperatures! I'm keeping my fingers crossed.

As warm as this summer has been it doesn't seem to be dragging on and on like some summers are prone to do. Is it just me? Probably.

I'm certain a successful mid-summer excursion to the Antennas site helped me ease those "summertime blues." Yes, it was crazy - and if the weather conditions coop-erate I'd do it all over again. When you're starved for photons you'll do almost anything to scratch that itch. We came prepared to do battle with the heat, but just before the crack of dawn we contemplated the need for a light jacket. What a night. Hey, some-times you have to think outside the proverbial air-conditioned box to get what you crave.

Kudos to everyone who partici-pated in last month's Annual All-Member Show-and-Tell. I have to ad-mit I look forward to that meeting every year. It's yet another reason the Saguaro Astronomy Club is a top notch organization.

The September 9th meeting is right around the corner. We are very fortunate to have as our guest speaker Dr. Jeffrey Hall, the acting Director of Lowell Observatory. Hopefully we can get caught up on all the latest projects at Lowell. Hope to see you there!

See you under the stars…

Chris

Special points of inter-

est:

Officers and Contacts:

page 22

Meetings: page 22

Star Dates: page 22

Membership form: 23

Inside this issue:

Editor’s Drool

(Richard Harshaw)

2

Decisions, Decisions

(Darrell Spencer)

3

Das Gegenschein

(Tom Polakis)

5

She Blinded Me With

Science

(Mike Wiles)

7

Book Review

(Dave Hofland)

11

Nininger’s Museum

(Marjorie Williams)

13

Last Call

(A J Crayon)

15

Call for Observations

(A J Crayon)

19

Double Minded

(Richard Harshaw)

20

Saguaro Skies

From the Editor’s Cluttered Desk By Richard Harshaw

Sorry that this issue is a bit late in getting out. I normally like to have these out the week before the monthly meeting, but this late summer/early fall has been a whirlwind in our household and I have only just now been able to get to this issue.

I think this month’s is of the usual high caliber you star crazies send me, and I appreciate it! I am sure your fellow SACers do too.

I’d still like to do an issue this fall on imaging, if I can talk some of you imaging folks to add a few words to your awesome images and send them in. (I won’t mention any names, but I will drop a few initials— Lori P., Al S., Paul L., Steve M., Mike W. (ok, Mike has a great article in this issue already), Gene L., etc.) Okay, so I dropped MORE than the initials.

Fall is upon us and that means a drop in temps and a general clearing of the skies and the return to our prime desert sites. Here’s to a great season of awesome observing with good friends, good skies, and finely figured glass!

Page 2 Saguaro Skies

For Sale:

Orion Premium DSE 10" F5.6, purchased new in 2001 for $900. Upgraded the JMI Crayford with a new draw tube with single set screw and brass compression ring, also has Telrad, two 1.25 eyepieces ,and owners manual. This is a quality dob by Orion before they went to those metal tubes. The price is a steal at $450, so it is firm. Call Doug Allen at 623.856.5027.

Astrivia

(Astronomy Trivia)

The next Mars rover, named Curiosity, has had its landing site selected: at the foot of the layered crater Gale (named for Australian astronomer Walter Gale). The cra-ter is 96 miles across and holds a mountain rising about 3 miles. Curiosity is scheduled to land next August and will look for signs of microbial life.

Decisions, Decisions! By Darrell Spencer

We sure are faced with some decisions and forced into some compromises as it relates to our choice(s) on tools for pursuing objectives (checking out the sky, in case you were wondering). Without being too trite in this discussion, it’s probably best to review just a bit before splashing the cash. This is true any-time one is seeking a new telescope, whether it’s a first instrument or a fifth. And here’s the trite part, “No single scope does everything well. So, your selec-tion should be based on a careful analysis of your ex-pected uses.” Hopefully, an equitable compromise can be made – unless your, uh, focus is very narrow in, uh, scope.

For the purposes of this article, I won’t delve into the world of refractors as my assumption here will be that visually chasing often faint DSO’s is the primary goal of most new observers. A refractor has many advantages over other designs. Light grasp is not one of them – unless they’re quite large and prohibitively expensive. So, they’ll be excluded from the discussion. (Sorry).

Most importantly for me, and since truly reward-ing observing requires traveling out of town, portabil-ity is paramount. Of course, there are a few hardy souls who routinely transport impressive instruments and are rewarded for that dedication. But it takes a lot of effort – and a capable vehicle and back. So, an in-strument that combines ease of portability and gener-ous aperture is attractive. Again, this assumes that at some point, your intended targets lean toward the faint, fuzzy variety. Truss Dobsonians have solved much of the burden of transporting large mirrored solid tube Newtonians. But, at the same time, these have become “premium” telescopes, effectively negat-ing the original intent of the Dobsonian. Setup and teardown is not trivial.

Some time ago, after careful deliberation, I began a serious survey of the sky with a 10” Orion Dob-sonian. I travelled far with that scope and found it to be easily transportable and of capable light-gathering ability. But, I worked a “trade” whereby I “upgraded” to a similar 12” Dobsonian for essentially zero addi-

Page 3 Volume 35, Issue 7

capital. Boy, was that a mistake. For me, the bulk of a 12” solid tube (even an f5) steps over the threshold for simple transportability. It wasn’t particularly heavy, but it was a handful. I can’t even imagine the task of lug-ging a solid tubed 17.5” Dobsonian around.

But, I really enjoyed the capabilities of that 12” Newtonian. Did I (or do I) want a bigger one? Sure. But, I really couldn’t justify the capital outlay for what I really wanted. I’m thinking 18” or bigger here. But there were other factors coming into play.

You see, I had begun to dabble in photographing things through (and on) the telescope. Tough to do with a Dob. And who wants a large GEM-mounted newt these days? Oh yeah, I tried a 10” EQ Meade Starfinder for a while and found it viable but not-so-transportable. And the mount left much to be desired. (I got some great lunar shots with that rig, though.)

It didn’t take long to realize what many others have long since discovered. Need decent aperture, portability, solid mount and tracking capability, versatil-ity, cost effectiveness, and scalability? The SCT fills the bill nicely. I have found an effective compromise with the compact form factor, long focal length and decent aperture. In fact, I’ve come to enjoy the design enough that I now have two, a GEM-mounted C8 and an older Nexstar 11 GPS. They’ve allowed me to easily and quickly pack up and go, set up when I get there, and reverse the process when I’m finished. Sufficient aper-ture still allows me to probe into the cosmos, even visu-ally. (I’m well into the Herschel 2 list). Accessorizing is all too easy. I’ve begun to realize I now have a decent platform to really get going with astrophotography – although I’m still trembling at the gate. And, best of all, I purchased on the used market and saved a bundle of cash.

In spite of the benefits, did I make some compro-mises? Perhaps. Diminished contrast, mirror shift, a not-so-flat-field and a reliance on electronics are part of the deal. But, if the lights happened to go on at one of our dark site gatherings, you’d catch me with a big, sat-isfied grin.

(continued next page)

Decisions, Decisions (Cont’d)

But that’s just me. What matters at the end of the day (when the stars come out) is not so much the equipment and/or optical configuration you’re using, but that there’s a tool available and in use.


The C-8 on a GEM Mount

The ubiquitous C-11 on the

NexStar mount. The Editor’s C-11 on a CI-700 mount is in the back-ground.

Scene from Cherry Road site.

Astrivia

Astronomers using the Hubble Space Tele-scope have discovered a fourth moon orbiting Pluto and have designated it P4 (to go along with Charon, Nix and Hydra, the last two discovered by Hubble in 2005). It is a dinky thing, only 8-21 miles across (the variability depending on its true al-bedo). Compare that to Charon’s 700 mile diame-ter. The sizes of Nix and Hydra are not well estab-lished yet.

The moon system is thought to be the result of a collision between a dwarf planet and a normal planet early in the formation of the Solar System.


Visual observers in Arizona are spoiled by dark and dry conditions at our sites. We hear about the Zodiacal Light being faintly visible to astronomers east of the Mississippi, while it can reach nuisance levels of brightness in the Southwest. Less commonly described is the Gegenschein, an oval haze along the ecliptic that resides 180º from the Sun.

Descriptions of the Gegenschein date back to the early 18th century. In 1800, it was the German ex-plorer Alexander von Humboldt who coined the name, which translates to “countershine.” The first paper on the subject appeared in the German journal “Astronomische Nachrichten” in 1855. It was au-thored by the Danish astronomer Theodor Brorsen, who is also known for his co-discovery of periodic Comet Brorsen-Metcalf. Brorsen correctly observed that “the brightest part lies exactly opposite to the sun.” Later, he deduced that the Zodiacal Light and Gegenschein are the same continuous band of Solar System dust that is favorably illuminated by the sun.

Harvard College astronomer Arthur Searle paid close attention to the Gegenschein in the late 1880’s, describing its shape and position accurately. Like Brorsen, he noticed that it is most visible around the Equinoxes. E.E. Barnard provided this description: “…20º in diameter, roundish, resembling a patch of dense haze or fog, pretty even in light, ill defined bor-ders.”

As detection and measurement methods im-proved, it was learned that the glowing region is not located exactly along the ecliptic, being shifted to the north in September and to the south in March. Alter-native explanations for the Gegenschein emerged as a result. As recently as 1962, Berkeley astronomy John Brandt proposed that the earth has a gaseous tail which is best seen at opposition. Despite the benefit of over a century of knowledge, Brorsen’s 1855 explanation remained the correct one.

Why is the Gegenschein north or south of the ecliptic? The answer lies in the fact that the ecliptic is no more than an arbitrary reference plane of the

Das Gegenschein By Tom Polakis

earth’s orbit – it has no influence on the Solar System. In fact, the concentration of meteoritic dust lies in the invariant plane, which is the weighted average of the all of the planets’ orbital planes. Accounting for this plane’s 1.5º inclination to the ecliptic, the Gegen-schein’s observed position lines up with the predic-tions.

Throughout the years, the Gegenschein has proven extremely difficult to photograph. No photo shows it better than this one from Paranal Observa-tory in Chile taken with a 10mm lens by Yuri Beletsky: http://www.eso.org/public/images/eso0812d/ .

Lining this image up with a star chart, it becomes apparent that the Gegenschein is shifted slightly to the north of the ecliptic, typical for October observa-tions. Note also the connections to the Zodiacal Band, which is at its faintest before meeting with the brighter Gegenschein.

I have found that the degree of difficulty of visu-ally sighting the Gegenschein is generally overstated. Of course dark skies help, but I see it routinely at Ve-kol Valley, a mere 45 miles from the intersection of Central and Washington. You just have to know where and when to look. Regarding when, it is only visible when it’s not immersed in the Milky Way. That eliminates the months of June and July, when the background glow of Scorpius and Sagittarius ruin the contrast. The same is true when it traverses

(continued next page)

http://www.eso.org/public/images/eso0812d/


Das Gegenschein (Continued)

Astrivia

The Native Americans have a wonderful name for astronomers: “the people with the long eyes.” And that is really true of the latest discoveries in the infra-red. Using the 4-meter VISTA IR survey telescope in Chile, astronomers have found 96 new open star clus-ters that are hidden from us who use light in the visual band because they lie behind obscuring dust clouds and gas. Most are small (10-20 stars) but a few are stunning, rivaling anything in the Messier catalog. Re-searchers expect to find many more of these hidden “opens”.

Click this link for more details:

http://www.eso.org/public/news/eso1128/

Taurus and Gemini in December and January. The best views can be had in October and November, when the Gegenschein is presented against the bland star fields of Pisces and Aries.

And what is up with the title about the stargazer’s clock? When I am in a state of mind for viewing faint galaxies, I only want to be vaguely aware of the time. If you know where south is, the Gegenschein provides a natural clock that will get you within an hour. Since it reaches the meridian at local midnight, just estimate how far to the east or west of due south it is. That will correspond with the number of hours before or after midnight. From the darkest sites, I have seen the Gegenschein on the verge of setting in the west as the first glow of morning twilight comes up on the other side of the sky.

Tom Polakis is a veteran Arizona observer with many credits to his writing portfolio, including many articles and images in popular astronomy magazines.

Our President (Left) and Tom Polakis trying to prove that Newton was wrong.

Final score: Earth 1, Hanrahan/Polakis 0.

The much brighter and differently located Zodiacal light.

http://www.eso.org/public/news/eso1128/


She Blinded Me With Science By Mike Wiles

Amateur astronomy has long been a pursuit that loves to debate the controversial topics, even from its earliest days. All those hours spent studying, observ-ing and watching the sky frees the mind enough that it can form hypotheses and compare them with those of nearby observing companions. The earliest known controversy occurred one night long ago when one observant dinosaur looked to the heavens and said, "Look, a meteor! I think it's going to hit the ground!" His observing buddy looked up, pondered the scene for a moment and said, "No it isn't." History doesn't record for us the rest of that conversation. Thus was established the scientific method as it's typically prac-ticed in amateur astronomy circles. These discussions contributed to some of the most fundamental phi-losophical changes ever conceived in the early 1600's when everyone in the world said "The Earth is the center of the Universe". To which Galileo simply re-plied, "No it isn't."

A topic that seems to generate slightly less de-bate amongst modern amateurs is the subject of star party light pollution and there' s no shortage of opin-ions on the topic. With the advent of electronic go-to telescopes, CCD Cameras and modern astronomical software the laptop computer has invaded star par-ties worldwide. The encroachment of electronics onto the observing field has been one of uneasy ten-sion since the successful release of the Meade LX200 line of go-to telescopes back in 1992. The noise of the coffee grinder mount slewing across the sky for-ever changed the landscape of the star party. In the years since, more and more electronics have come to the observing field. Among them has been the ad-vent of the laptop computer and a significant amount of controversy.

Some observers swear by them and their use in the field. Some observers insist that they're a nui-sance and have a disruptive influence on productive visual observing. The modern astrophotographer has little choice but to use a laptop computer in the field for CCD imaging. The problem is that a laptop com-puter can generate an enormous amount of un-wanted light on the observing field if they're not

properly shielded. Some would maintain that it's not possible to properly shield a laptop computer in the field to preserve night vision. For someone who has a deep love of hopeless addiction to astrophotography like I do this presents a conundrum. I also enjoy vis-ual observing and the fellowship of observing with other members of the club. In the interest of full dis-closure, I was quite cranky when astrophotographers were sequestered to a separate end of the airstrip at this year's Messier Marathon. "My laptop and the way that it's shielded is less damaging to night vision than many of the red lights that I see on the observ-ing field on any given night!!". "Why do we have to go to the North end of the observing field? The visual observers should have to move to the south end if it bothers them so much!!" My own reactive hyperbole does nothing to further the discussion or find a way for all observers to co-exist peacefully. So instead of writing my own defensive but highly entertaining rant, I've opted to stage my own informal experiment to compare the effects of various observing field light sources on night adaptation.

Test Subjects My test is designed to measure the amount of

light pollution generated by five different test sub-jects:

Laptop Computer - Unshielded: Anyone not named Ray Charles knows that this will be the most obnoxious test case in the group. The test will be done using a 16.4" Sony lap-top and a SkyTools 3 generated chart of M31 with the laptop screen at full brightness. No red film or "night vision mode" is employed for this test.

Laptop Computer - Shielded: Naturally this will be a test of the laptop as I use it in the field. I have used a laptop for almost 10 years in the field, even for visual observing.

continued next page

She Blinded Me With Science (Continued)

The test will be done using the same laptop and a SkyTools 3 generated chart of M31 with the laptop screen at minimum brightness and covered with a sheet of fitted, dark red acrylic plastic. In addition, the "night vision" mode implemented by SkyTools 3 will be turned on.

Regular Star Chart/Dim Red Light: A common red LED flashlight (Celestron Item #93588) with the dial set to "minimum" and a chart from Uranometria 2000.0. The light itself will be sus-pended over the chart about 8 inches (20cm) away from the paper to approximate a typical observer's use in the field.

Regular Star Chart/Medium Red Light: The same LED flashlight with the dial set to its halfway point and a chart from Uranometria 2000.0. The pur-pose of the medium light test is to establish a re-sult for a standard red light that is typical of an average observer's use.

Regular Star Chart/Bright Red Light: The same red LED flashlight and Uranometria chart, this time with the brightness dial set to "maximum".

Test Conditions The Eye: To provide an objective means of meas-

uring the results I employed a Canon 60D DSLR camera operating at ISO 800 with an 18mm f/3.5 lens. This is in an attempt to approximate the optical specifications of the average human eye without a negative impact on the financial specifi-cations of this particular observer's bank account.

The Measurement: Each test subject will be pho-tographed in a darkened room in aperture priority mode. By using aperture priority mode, the

camera will adjust the length of the exposure based on the amount of light hitting the light me-ter (center weighted average metering). A shorter exposure indicates a more destructive light source. A longer exposure indicates a more night vision friendly light source.

The Observing Conditions: Measurements will be taken from two distances. The first will be from 30 inches (76 cm) to approximate the effect of the light source on the observer that might be using it. The second will be from a distance of 10 feet (3 m) to approximate the effect of the light source on a nearby observer.

Test Results I conducted all of the photography in my state

of the art darkened laboratory which also doubles as the storage room for my astronomy and camping gear in its spare time. I conducted all of the tests as de-scribed before learning that there wasn't a memory card in the camera. I put a memory card in the camera and conducted the tests again. The table (next page) lists the results of each test scenario. As would be ex-pected an unshielded laptop computer will instantly turn you into one of the fabled three blind mice. The main point of the experiment though was the compari-son of a shielded laptop with that of a standard red LED flashlight. Results show that a properly shielded laptop computer is no more damaging to an observers night vision than the ubiquitous red LED torch that we all use - placing 2nd overall of the five test cases.

In the table are the test results listed in order from the dimmest to the brightest. The 2nd and 3rd columns show the results of the tests from a distance of 30 inches. My patent pending and proprietary "Fried Retina" Factor measures the additional light output of each additional test when compared

(Continued next page)



Bright Red Light: This light was really, really bright. I can say that I've never seen an observer use a red light to look at a star chart at this setting. I have used a light at this setting when crossing the observing field to keep an eye out for tripping hazards like dark colored dogs sleeping on the ground or random satel-lite dishes. Don't laugh. I've found myself face first in the ground because of both.

She Blinded Me With Science (Continued)

to the dim red light test. For instance, an unshielded laptop is 250 times brighter than a dim red light. The 4th column shows the test results as measured from a dis-tance of 10 feet - designed to measure the effect of the light source on nearby observers. The magnitude col-umn attempts to express the results in the form of star magnitudes as another basis of comparison. For in-stance, if an unshielded laptop is equivalent to Vega (0.0 magnitude), then a dim red light shines with the magni-tude of a 6th magnitude star.

*FR Factor - Fried Retina Factor

My own subjective thoughts on the experiment:

Dim Red Light: The output created by the light source at this setting would have been unusable for me. Ten years ago I would have been able to use this light with a chart, but there's no way that I could do it now with my aging peepers. I believe that very few observers would be able to use the light at this dim setting.

Shielded Laptop: The laptop with all of the shield-ing methods in place is a about 1/2 f stop brighter than a dim red light. This is right in line with a typical observers red flashlight that I typically see on the observing field. I did find it interesting that at a distance of 10 feet the laptop appears to be marginally brighter than a red light at medium setting. This is almost certainly due to the fact that it's still a backlit light source.

Medium Red Light: This light setting is a touch brighter than what I see from most observers at a star party and would be too bright for me to use without damaging night vision unnecessarily. I actually added this test after completing the other four in an effort to provide a fairer comparison of real world conditions.

Test Case 30 in. Exposure FR Factor* Magnitude 10 ft Exposure

Dim Red Light 5 seconds 1 6.0 8 seconds

Shielded Laptop 3.2 seconds 1.56 5.6 6 seconds

Medium Red Light 2 seconds 2.5 5.0 8 seconds

Bright Red Light 1/3 second 15 3.4 4 seconds

Unshielded Laptop 1/50 second 250 0.0 .6 seconds

Comparison photo showing a 3.2 second exposure of a shielded laptop (top), and a medium brightness red LED flash-

light.

Continued next page

She Blinded Me With Science (Conclusion)

Conclusion In a case of astronomy imitating life, everything

old eventually becomes new again. The laptop com-puter, go-to hand controller and Smartphone are sim-ply new expressions of an old issue: proper light con-trol. A properly shielded laptop is no more damaging to night vision than a properly shielded flashlight. Even with the influx of technological advances to the observing field the age old task of maintaining proper dark adaptation is still the same, just in a different form. Without question, there are additional precau-tions necessary with many laptops. In my case I gener-ally take four steps with my laptop on the observing field to properly shield it for myself and my fellow ob-servers:

1. Red Fitted Acrylic Cover: I cover the laptop screen with a dark red fitted cover and tape it down to prevent any unfiltered light from leaking out of the screen. These can be cus-t o m o r d e r e d f r o m h t t p : / /www.tapplastics.com/shop/product.php?pid=519 . I also cover every indicator light on the laptop with electrical tape.

2. Red Light Mode: Most charting/observing programs have a night mode that will turn everything on the screen to a red light type of color scheme in an effort to help. I use Sky-Tools 3. The red light mode in Sky Tools 3 turns everything on the screen black and all of the relevant text to a deep red. In conjunc-tion with a red plastic cover, the screen is very readable.

3. Adjust Screen Brightness: I adjust the screen brightness to be as dim as possible. These three steps were taken to create the results in these tests on a 16.4" laptop screen.

4. Point the screen to the North: I try to setup so that the laptop screen itself is always pointed to the north on the observing field.


Few observers are ever trying to observe an object that is low in the north, so this setup puts my screen out of the line of fire of almost every observer on the field.

I don't expect that this will be the final word on the subject. Astronomers love a lively debate and this will continue to be debated long into the future. I simply hope that my admittedly unscientific experiment has added to the discussion in a positive manner.

A relative newcomer to SAC, Mike has already dazzled us with his stunning astronomy images and his great sense of humor and wit. His rules for astrophotogra-phers are destined to become part of amateur astron-omy lore as famous as Thraxendall’s Postulate (which governs how much bad weather the purchase of a new astro toys generates) and Gumperson’s Corollary (a spinoff of Thraxendall’s Postulate that describes the geographic area affected by the weather induced by a new astro toy.)

"Have fun, keep your dark adaption, and Remember, Raccoons like Oreos!"

—Jay Reynolds Freeman


Deep Sky Companions: The Secret Deep

Steven James O’Meara

Cambridge University Press 2011

Like many of you, if I can’t get outside at night to observe for whatever reason I still have a desire to be doing something . . . well, for lack of a better word “astronomical”. If there isn’t anything about astron-omy on TV then I like to read about astronomy. I’ve got a lot of books about astronomy and among my favorites are O’Meara’s Deep Sky Companions series of books.

Steven James O’Meara is well known within the astronomy community. Steven began observing the night sky at the age of 6 in the suburbs of Boston Mas-sachusetts and by the age of 14 he was able to impress the Astronomy faculty at Harvard with his knowledge such that they gave him access to the university’s ob-servatory. He’s been a contributor for some time with his column “The Secret Sky” in Astronomy magazine. Steven is a well-known speaker at several popular star parties across the US, and earned the Omega Centari Award from the Texas Star Party for his "efforts in ad-vancing astronomy through observation, writing and promotion, and for sharing his love of the sky." He was also featured in the Tim Ferris PBS documentary “Seeing in the Dark”. In addition to his pursuit of as-tronomy, Steven is also well known for his work with his wife Donna in the field of volcano research and together the pair has traveled the world documenting and photographing active eruptions.

The Secret Deep, published by Cambridge Univer-sity Press (www.cambridge.org) is the 4th volume in Steven James O’Meara’s Deep Sky Companions book series. The three prior Deep Sky Companion books are The Messier Objects, Hidden Treasures, and The Cald-well Objects. Following the format of the prior three, The Secret Deep features an in-depth look at each of 109 astronomical objects from the perspective of the visual astronomer. Here is what the publisher has to say about the new book.

“In this fresh list, Stephen James O'Meara presents

109 new objects for stargazers to observe. The Secret

Deep list contains many exceptional objects, including

a planetary nebula whose last thermal pulse produced

a circumstellar shell similar to the one expected in the

final days of our Sun's life; a piece of the only super-

nova remnant known visible to the unaided eye; the

flattest galaxy known; the largest edge-on galaxy in

the heavens; the brightest quasar; and the companion

star to one of the first black hole candidates ever dis-

covered. Each object is accompanied by beautiful pho-

tographs and sketches, original finder charts, visual

histories and up-to-date astrophysical information to

enrich the observing experience. Featuring galaxies,

clusters and nebulae not covered in other Deep-Sky

Companions books, this is a wonderful addition to the

series and an essential guide for any deep-sky ob-

server.”

I own all three of the prior Deep Sky Companion books and I can attest that it lives up well to the pub-lisher’s description although to say it is an “essential guide for any deep-sky observer” is a bit of hyperbole. A very good book, yes. A “wonderful addition to the se-ries”, certainly. An entertaining read with interesting information, unquestionably. “Essential….” that might be a little strong. But let’s not let a little puffery in ad-vertising detract here— it really is a good book and while perhaps not an “essential guide”, it is without a doubt a very useful reference. This book, along with the three prior books in the Deep Sky Companion se-ries, is one that any deep sky observer will appreciate having in his or personal reference library.

Steven has a writing style that engages and enter-tains as much as it informs and this makes his books a lot of fun to read. I also find that observing is a lot more interesting if I know something about the objects prior to targeting them and in this book, as in the prior three, each object is covered by several pages of infor-mation along with nice photos, a sketch, and a star chart to aid in finding and identifying the selected ob-ject.

continued next page

Book Review: Deep Sky Companions: The Secret Deep By David Hofland, SAC Member from Alabama

So is there anything I didn’t like? No good review is complete unless it points out a few drawbacks so here goes. Perhaps a bit of a misnomer, the title “The Secret Deep” should not be taken too seriously to sug-gest these 109 objects are all obscure, little known and/or difficult objects. Many of these objects are anything but “secret”, and most are brighter than Vmag 11. Most of the objects in this book are included on AL and SAC awards program lists such as the Globu-lar Cluster Club, Planetary Nebulae Club Herschel 400, SAC 110 Best, and Herschel II and SAC 110 Best Be-yond the NGC. And beware that you may find small errors. For example, the sketch for NGC 654 “Secret Deep #4” has a scale mark labeled as 30’ which is a clear error. The object is 6’ in diameter and the object sketched is drawn as more than twice as large as the little line labeled as 30’ size. I checked several of the other sketches and didn’t find any more obvious errors but if there is one there may be more. Finally, to me the “Additional 20 Objects” are of little value to the book. All that is included for these is a list with the object ID, coordinates, Vmag., constellation, etc. (There are 21 actually listed though two are a closely located pair so I guess that’s why the list is titled “20 additional objects,” but there are 21 objects on the list!). Nothing anywhere in the book explains why those particular objects are included or describe any relationship to the featured 109. Maybe it’s just me, but unless there is some relationship to the 109 fea-tured, or some small write-up, why bother? Why stop at 20? Why not another 30, 50, or 100? It would only take another page or two . . . I don’t get it.

Overall though I still give this book a thumbs-up. It’s fun reading on those cloudy nights when I have a craving for something astronomical and I can’t go out-side with a telescope. And it’s a valuable resource of information for observing these targets when the skies are clear and welcoming.

Dave Hofland observes the skies from steamy Alabama and often dreams of observing in Arizona.


Book Review (Continued)

Astrivia

Astronomers using the Keck II telescope in Hawaii have confirmed that the dwarf galaxy Segue 1 is the richest in dark matter of any galaxy yet measured. The total dark matter was calculated from the meas-ured distribution of star velocities; then the visible matter was subtracted to yield the mass of the dark matter. The measurements also showed that the stars in this dwarf are unusually low in heavy ele-ments. Detailed spectra of the iron lines were made of 7 stars and 3 were found to be exceptionally low in iron (2,500 times less than in the Sun), making them some of the most primitive stars known. Only 30 stars in the Milky Way have iron abundances that low.

Segue 1 contains only about 1,000 stars!

Segue 1, at the center of this frame (expand image to start to see it)


believe there was no great mass of iron at the crater, because he found too much heavy metal in the dirt. He suggested diamonds could have been created in the fall process because he found many samples of carbonados, or black diamonds.

Nininger Ruins

The highway was rerouted in 1949 causing Nin-inger near physical, mental and financial collapse. Deep in debt, finding no buyers for his 5,000-piece meteorite collection, and discovering he was tied into his lease of the rock building for another three years, Nininger and his family were at the nadir of their exis-tence. “Bitterness had been growing, and fear - some-thing I had hardly known before.”

The Niningers survived somehow and when friends loaned them money, they built the American Meteorite Museum in Sedona. At that time Harvey Nininger could claim the discovery of more than half the meteorites in the United States. Then the Sedona business failed to work. Finally, in 1958, Nininger sold 21% of his collection to the British Museum of Natu-ral History for $140,000. He had gallantly tried to keep the collection intact and in Arizona but could no longer protect it. Two years later Arizona State Uni-versity achieved the funds of $275,000 and bought the remainder of the collection at a price far below the listed value.

continued next page

Nininger’s First Meteorite Museum By Marjorie Vin Williams

As you turn south from Interstate 40 to visit the Bar-ringer Crater (Meteor Crater, Canyon Diablo Crater), a short distance from the interstate and to the left, you will notice a strange tower with rubble below it. The structure seems lonely on a rise of high desert. It looks like the ruins of Canyon Diablo, but it also looks like ruins of the Anasazi peoples of centuries ago. There are the remnants of a beautiful stone structure. You are com-pelled to ask at the nearby gas station, “What is that?” The store clerk will drag out a picture or point to one on the wall of an imposing and large building, the first Ari-zona meteorite business of Dr. Harvey Harlow Nininger, meteorite hunter, meteorite collector and meteorite his-torian.

In 1923 Harvey Nininger (1887-1986), a Kansas col-lege biology teacher, saw a bright meteor, called a fire-ball, and became enchanted with meteorites. After World War II, Nininger moved his wife and two children into a trailer behind a flagstone-towered building north of Meteor Crater. This move began a business in meteor-ites and established a meteorite museum on Route 66. The world looked good.

Within a short time, the friendly atmosphere with the Barringer family of the crater and Tremaine family of the surrounding ranch faltered. In 1948 “exclusive rights” were granted to the University of Mexico to recover me-teorites and conduct meteorite surveys. The 1949 press announcement about this also mentioned that Otto Struve, president of the American Astronomical Society, compared Meteor Crater with the 1947 site of a fall in Siberia. Struve reported it should have been made a na-tional monument. Nininger also stated, “The Arizona cra-ter is a great part of our national heritage and should have been so treated from the first; since it was not, cer-tainly now it should be acquired and given to the public as part of the national parks system.”

Nininger had attached a suggestion to his Arizona’s Meteor Crater book that one should look for coesite, quartz that occurs from a tremendous heat and pressure (shocked quartz) near the crater. Unable to collect mete-orites near him because of the friction between the two families, he continued his study of the soil and began to


Read Find a Falling Star by Nininger to understand with pathos the lifelong struggles and devotion of Nin-inger and his family to this specialized science. Seeing the ruins of his first business will imprint even more thought about his dedication.

Marjorie Williams is known to SACers as the astro-archeology lady! Here she is atop Shaw Butte at the old observatory used by people who far pre-dated us. The geek next to her is Jimmy Ray.

Nininger’s First Meteorite Museum (Concluded)

A petroglyph on Shaw Butte

Astrivia

The LMC is a thief! It has stolen stars from the SMC.

By analyzing the spectra of 5,900 giants and super-giants in the LMC, astronomers found that over 5% of the stars observed are rotating counter to the direction of the majority of the LMC stars. These peculiar orbits indi-cate that these stars probably did not form from the ro-tating and collapsing cloud of gas that formed the LMC.

Further examination of these counter-rotating stars revealed another anomaly: their chemical compositions are different. They have fewer heavy elements than typi-cal LMC stars, but their composition closely matches those in the SMC.

The theft hypothesis might also help explain why there is an unusually large amount of star formation in the LMC nebula called The Tarantula. (If the Tarantula were placed where the Orion Nebula is, it would fill all of Orion and its light would cast shadows.) The Tarantula is located at the position where gas from the SMC that is being pulled into the LMC along with the captured stars collides with the LMC’s own gas at high velocity. The re-sulting shock wave pressurizes and concentrates the gas, making starburst possible.


Last Call Compiled by A. J. Crayon; sketches compiled by Rick Rotramel

Selecting Sagittarius for the summer is risky be-cause of our monsoon weather patterns. Unfortunately if this is used as an excuse to ignore this constellation, then we will miss many fine deep sky objects. Fortu-nately for this month most of the objects are either in the Messier Catalog or Herschel 400. This is not the last time we will see this constellation— it can be visited sev-eral times in the future before we complete it list.

Thanks to Richard Harshaw for supplying interesting and historical information about each object.

We start in Sagittarius with M20, the famous Trifid Nebula. Observers were urged to comment on double stars and dark lanes.

It was discovered by leGentil in 1747; Messier cata-loged it on June 5, 1764. He mentioned it only as a clus-ter of stars. William Herschel named it for the three radial dark lanes that seem to emanate from the dou-ble H N 40. Harold Corwin has a great his-torical note on this ob-ject at the NGC/IC Pro-ject web site.

8X50 finder; AJ Crayon: 2 stars with M8 to south.

14x70 Binos; Richard Harshaw: Large and fairly bright (near the center).

8” SCT at 83x; Richard Harshaw: The lanes are a cinch. High power works wonders for the details. It contains the double star H N 40.

8" f6, Newtonian at 100X; AJ Crayon 10', 6th mag; large, bright nebula, irregularly round with 3 dark lanes radiat-ing outward from near center. The dark lanes are about 40" wide. There are 10 stars in the nebulosity. In the field, 10' north is 10' nebulosity, round with 12th mag central star visible. All in a very, very rich field.

11” SCT at 88x; Richard Harshaw: Very easy object with sharp lanes. Surprisingly, an OIII filter did not help.

14.5” f5.2 Dobsonian at 145X; AJ Crayon: A beauti-ful emission, reflection and dark nebula. It is 6th mag and 30' making it bright, large and irregular. There are two prominent dust lanes emanating out from the center, one in a Northwest and the other in a south of southeast position. The third is rather com-plex, not as well defined and is in a westerly posi-tion. There are 2 bright stars in the center where all 3 dark lanes meet. This is a double–double star. The brightest nebulosity is to the east and faintest is to the southwest. There is more nebulosity to the north and is the reflection part. The field contains many stars from 7th to 14th mag. The dark nebula is B 85.

16" f4.4 Newtonian, Rick Rotramel: OC/GN - L, B, ~30 stars, two large glows, one reflective, the larger one emissive, three major dust lanes in the emission nebula, Fantastic!

Next is M8, the Lagoon. Many observers com-mented on the involved open cluster NGC6530 and the dark lane. The 3 exclamation marks are to indi-cate this is a magnificent or otherwise interesting object. I would agree with that. Would you?

M8 was discovered by John Flamsteed in 1680; De Cheseaux added it to his 1746 list, and leGentil to his list of 1759. leGentil described it thus: "This neb-ula has exactly the shape of a slightly elongated isos-celes triangle with the point towards the SW... To me it always appears nebulous and transparent: it touches at its base, a fairly bright star, seen in the telescope." Lacaille put it on his list in 1755, as did Koehler (1780) and Bode (1779). Messier added it to his catalog on May 23, 1764. Its true size is 60 light years by 44 light years.


NGC6530 was discovered by Giovanni B. Hodierna in 1654. It is 7.4 million years old, with the earliest spectral type being O5. This cluster lies 22,800 light years from the galactic center and 120 light years be-low the galactic plane. It is at the heart of the Sagitta-rius-Carina Spiral Arm.

In 1987, naked eye from Dugas Rd; AJ Crayon: easily seen naked eye, round.

8x50 finder; AJ Crayon: 8 stars in large, round milky nebulosity.

14x70 binos; Richard Harshaw: Very large and bright stellar nursery.

8” SCT at 83x; Richard Harshaw: Fantastic! It almost rivals M42 in Orion. The dark lane is easy, and the cluster NGC 6530 is clearly visible. The dark nebula that surrounds a 12th mag star just W of the center is the hourglass constriction that gives this nebula its alternate name. (The hourglass is framed by blue-white 9 Sgr to the E and H 36, a 9.55 mag double to the W.) The W lobe is brighter. An ultra-high contrast filter (UHC) brings out more of the nebula, but it also dims the illuminating stars a great deal.

NGC6530 is overwhelmed by M8 to the E. It has two separate clumps of stars.

Last Call (Continued)

Image © by Chris Schur. Used with per-mission.

8" f6, Newtonian at 100X; AJ Crayon: 30', mag 5.5; The Bayou Nebula is my designation! [Editor: what else should we expect from a Cajun?] It is very bright, irregular shape nebulosity with a bisecting 2' dark lane in a northerly position. It enlarges to about 10'X15' in an easterly position and includes the bright 6th mag star 9 Sgr. There is another bright nebulosity called the Hour Glass, is 30" and just west of dark the lane (the bayou!). The involved open cluster NGC6530 is east of the enlarged dark area in the nebulosity and is about 10' with 20 stars 8th to 14th mag limit of the scope.

14.5” f5.2 Dobsonian at 90X; AJ Crayon: A magnifi-cent open cluster (NGC6530), dark nebula (B 88) and emission nebula (NGC6523) that stands out well with low powers, is visible in a 9X50 finder and naked eye. It is extremely bright, very large and irregular. The nebula is divided by a long narrow dark lane in a north-easterly position, to which this observer calls the Bayou Nebula. The Northwest part, or lobe, is the brighter and contains a larger part of the dark nebula, to which all other observers call it the Lagoon Nebula. On the east side is the cluster NGC6530 that is in-volved with a fainter nebulosity. The west side con-tains the brightest nebulosity, called the Hour Glass. A study of this magnificent object at high power should prove to be quite interesting.

continued next page

Sketch by Richard Harshaw, 8-in SCT,

from Kansas City, MO in the early 1990’s



The globular cluster NGC6540 is also known as Djor-govski 3. It is small, as in 0.8’, and faint, as in mag 14.6 and is considered to be a little elongated.. No wonder the 8’ telescopes had a hard time seeing this one.

NGC 6540 was discovered by William Herschel in 1784 and cataloged as H II198.

8” SCT at 104x; Richard Harshaw: Faint, averted vision will be a big help in seeing it. It boasts two arcs of stars and a dense center. Rich field.

8" f6, Newtonian at 100X; AJ Crayon: 3' stars involved, it is partially resolved with averted vision. The field has 200 stars 7th to 14th mag limit of the telescope.

14.5” f5.2 Dobsonian at 140X; AJ Crayon: pretty small and faint; 6' and 10th magnitude. In a busy Milky Way field that includes a dark cloud. There are some bright stars involved.

16" f4.4 Newtonian, Rick Rotramel: GC - S, F, pRich, shaped like an elbow macaroni, ~15 faint stars.

While we are on a globular cluster, NGC6553 is next. It is much brighter and larger than the last one! Its brightest star is mag 15.3 and has stars as faint as 20th mag. (Doubt we saw any of those.) Few seemed to detect its suggested elongation. Perhaps it isn’t elongated enough.

William Herschel discovered it in 1784. The brightest stars are 14.7 mag and the horizontal branch is 16.2 mag. It is reddened 6.3 mags.

8" f6, Newtonian at 120X; AJ Crayon: 10', 10th mag; very gradually little brighter elongated middle in a northeast position that is partially resolved. There is an 11th mag star just to the south. The field has 80 stars 7th to 14th mag limit of the telescope, to north is V3792 center on V3792 and see NGC6544 and NGC6553 at edges of 1° field.

8” SCT at 104x; Richard Harshaw: Unresolved, and a faint star lies on the edge. Very rich field.

11” SCT at 98x; Richard Harshaw: Not resolved, it is faint and small. A wide pair (11 m) is 3' E.

14.5” f5.2 Dobsonian at 140X; AJ Crayon: pretty large, pretty bright, with 4 faint stars involved in the 11th to 12th magnitude range and a nice halo.

16" f4.4 Newtonian, Rick Rotramel: GC - fL, fB, vRich, nearly round, same brightness throughout, with a bright star on the north end.

Next is the planetary nebula NGC6567. It is very small, stellar and 11th mag. It is very near two 11th mag stars and all 3 look like a Mickey Mouse hat. A finder chart may make locating the little one much easier as no observations were turned in.

continued next page

M8 sketched by Tom Po-lakis,

8-inch scope at 30x, from the Dugas Road site

Another Polakis M8, this time with a 13-inch scope

at 75x, from the Vekol Road site


Next is M25, a compressed open cluster that in-cludes U Sagittarii and has stars from 6th to 10th mag. It has 30 stars from mag 6.7 and a Trumpler code of I 2 p.

De Cheseaux found this cluster in 1746, and Messier cataloged it on June 20, 1764. It is 9 light years in diameter and 92 million years old.

14x70 Binos; Richard Harshaw: Six stars resolved, S of a nice triangle of stars.

8" f6, Newtonian at 60X; AJ Crayon: not found, not for casual stuff in Sagittarius Star Cloud!!

8” SCT at 65x; Richard Harshaw: Note the trapezoid at the center. There are many O and R stars, and a bright Y star near the center. It looks best in a wide field.


Over in the eastern part of the constellation is the globular cluster NGC6717, also known as Palomar 9. It is just south of 5th mag Nu Sagittarii. We asked how much does the 5th mag star impact the view. There were some replies. Despite having rather faint stars starting at 14th mag, it is resolvable. Note in Richard Harshaw’s observation he refers to Nu 2 Sgr as a 5th mag laser. What does that mean? (Editor: It means it is one terribly bright sucker!)

William Herschel discovered this cluster and cata-loged it as H III 143. He described it as a very faint round nebula and apparently thought it was a cluster with nebulosity. It was first recognized as globular cluster by Per Collinder in 1931. When compiling his catalog of newly discovered globular clusters, George Abell (1955) included this object, apparently unaware of its identity, as it was not previously classified as a globular cluster. Its identification with NGC 6717 was probably done in 1958 by Alter.

8" f6, Newtonian at 100X; AJ Crayon: 3', 12th mag; moderate glow not resolved! The globular is 3' south of orangish 7th mag star Nu-2 Sagittarii.

8” SCT at 88X; Richard Harshaw: not resolved, but with a bright core. A brilliant star (8th mag) is 2' N. At 400X very faint and difficult cluster with Nu 2 being so near. Not resolved, but rapidly brightens to the center.

11” SCT at 140x; Richard Harshaw: It lies 2' S of Nu 2 Sgr (a 5th mag laser) that makes the seeing very diffi-cult. It is easily detected (but not resolved) at 140x, although it looked grainy. At 339x, it starts to resolve, and at 634x, Nu 2 can be nudged out of the field for a fine view of a very dense and resolved nucleus with extensive halo of grainy stars.

14.5" f5.2, Dobsonian at 290X; AJ Crayon: pretty faint, considerably small or a knot of 5 or 6 11th or 12th mag stars. It is just south of Nu 2 Sgr.

continued next page

M25 sketched by Richard Harshaw 8-inch SCT from Kansas City, MO Early 1990’s


Last Call, and Call For Observations (Continued)

The last object was the barred spiral galaxy NGC6902. No observations were submitted for this en-try. Perhaps being in downtown Sagittarius has some-thing to do with this? It is listed as mag 10.9 and 6’X4’ so it should be visible in our telescopes. This one will be put back in the to do list for Sagittarius for the next time around.

Call for Observations

Cepheus stars form a box with a triangle on top and in Greek mythology are named after Cepheus, King of Ethiopia. We visit this constellation after a hiatus of many years. We’ll start with NGC2276 and its companion NGC2300, both about 11th magnitude and about 4° east of Polaris. First NGC2276, which is a late barred spiral with a ring. It is pretty large and has a little brighter middle. Our next one is 6’ to the southeast is the elliptical galaxy NGC2300. It too is pretty large, a little elongated and has a brighter middle. Moving well to the other side of the constellation we continue with open clusters. First is NGC7235 (aka NGC7234), and is listed as small, poor and a little compressed. Naturally both are circumpolar. Next is NGC7261 and is listed as large, pretty rich and a little com-pressed. Does this agree with Trumpler’s description of III 1 p? Now on to the large, pretty rich circumpolar open cluster NGC7261. Again Trumpler’s description is III 1 p, and do you agree or not? Keeping in the same general area of the con-stellation is another circumpolar cluster NGC7380. It is pretty large, pretty rich and involved in some nebulosity but you will more likely than not need a UHC or OIII filter to pull it in. This cluster is on the Herschel 400 list, part of the Cepheus OB1 association. Finally Trumpler’s description is III 3 p n. Going to the northeast is King 19 and NGC7510, within 20’ of each other. Yet they are easy to distinguish. First check out

NGC7510, another cluster on the Herschel 400 list. It is fan shaped and has some pretty bright stars. Trumpler gives it an II 2 m n. Look for the region of faint nebulosity to the southeast. After this it should be easy to locate King 19, with a Trumpler code of II 2 m. Its brightest star is listed as 12th mag. Good luck with this one.

For October the constellation for us is Pisces particu-lar the southern part. You will need your galaxy observing eyes for this as that’s all in here for us, save one asterism for variety. And we start with the asterism called the Cir-clet of Pisces, which is about 5° and is large for an eye-piece field of view. So try your finder or binoculars. What about stellar color? It is listed as 3rd magnitude, can you detect if naked eye? It is located at R.A. 23 11.0 Dec +03 40. The first galaxy is NGC7541 a barred galaxy with mag-nitude of 11.7. How much detail can you detect? What about the 14th mag galaxy 3’ to the southwest? Moving east of 0h find NGC467. It is almost 12th mag and small. What other interesting items do you see in a 30’ field? Turns out two of them are out next objects. About 10.5’ northeast is NGC470 a spiral galaxy with a ring and a gradually brighter middle. The third in the same field is NGC474 and should be slightly brighter and larger. Is it? Why or why not? Comparing the size descriptions of these 3 galaxies has the first two as large and the latter as small, yet the size field indicates just the opposite. The reader is left to their own decisions about this fact. Next is a Herschel 400 object NGC524, a bright and large Sa galaxy. Continuing to the east is NGC676, another spiral galaxy. It is listed as very faint but has a magnitude of 10.5. Getting towards the end of this month’s selection is NGC718 another barred spiral that is supposed to have smooth arms. What about irregular features and brighter middle? Finally we come to NGC741, an elliptical galaxy considered faint and small. There’s NGC742 involved, at mag 14.3 and is out of reach of many telescopes. That’s all for now, get out observer, take notes and send them in for inclusion into this column.

Finder Charts and Observation Forms for this Call list are available on the SAC Web Page by follow-ing this link:

h t t p : / / w w w . s a g u a r o a s t r o . o r g / c o n t e n t /observing.html

and click the “Call for Observations” link.

http://www.saguaroastro.org/content/observing.html

http://www.saguaroastro.org/content/observing.html


Being Double Minded By Richard Harshaw

The fall is a great time of year for double stars! The temperatures make for some pleasant observing and the skies are usually pristine and clean (after the beat-ing of the monsoon). Luckily, the Milky Way is still well-placed to serve us a feast of dainty doubles, and the wonderful jewel fields of Perseus and Cassiopeia beckon to us.

Easy Pairs

In my observing database, I use a code which al-lows me to sort observations by impression at the eye-piece (from 1 to 5, 1 being “Stunning” and 5 being “Why did I even bother????”) and difficulty of the view (Easy, Moderate, and Difficult). My list sorted out to give me 79 pairs to select for this column, and I have drawn what I think are 9 of the best double stars any-where.

Let’s start with H IV 113, a William Herschel dis-covery located in Cygnus at 2102.3+3931. This is actu-ally a multiple star (with 8 components!— where does a multiple star become a star cluster????), but only two are reasonably bright, A and B. A is 6.62 mag and B I s 9.49 with wonderfully contrasted colors of deep yellow and deep blue. The pair is 19.2” apart in PA 299. If the Sun was shrunk down to the size of a base-ball, this system would be represented by a beach ball and a tennis ball 41 miles apart!

Now we’ll observe one of Wilhelm Struve’s stars, STFB 11 (STFB means it is listed in his second adden-dum catalog). You’ll find a 4.08 mag deep yellow pri-mary with a 9.58 mag very red companion 37” away in PA 311. Located in Pegasus at 2122.1+1948, this pair shares common and rather high proper motion, so is likely a true binary. The companion is also a spectro-scopic binary (1,111 day period). If you are up to it, there is a C star (12.42 mag) way off at 74” in PA 19. It is not easy!

The final easy star is STF 2848 in Pegasus at 2158.0+0556. You’ll find a nearly matched pair (7.21 mag and 7.76 mag) only 11” apart in pa 56, but with a very nice but subtle color contrast. (I’ll leave it for you to observe it to find out what it is.) Using our Sun as a baseball analogy, you’d have a pair of volleyballs 5.1 miles apart.

Moderate Pairs We’ll begin in the obscure constellation Equuelus

with STF 2742 at 2102.2+0711, alias Lambda Equ. You’ll find a nearly even pair (7.41 and 7.64 mag) just 3” apart in PA 216. I noted orange and white. What do you see? Webb notes that this is a beautiful pair.

Next, take a look at SHJ 345 (a John Herschel/James South pair) in Aquarius, at 2226.6-1645. A nicely matched pair of yellow stars, 6.32 and 6.48 mag, are only 1.5” apart in PA 33, but the magnitudes makes this a pretty easy split, so hence the Moderate rating. The pair shares proper motion, even though Hartung thinks it is optical. A scale model (Sun as a baseball analogy) has two basketballs about 850 feet apart.)

Before driving you nuts with the difficult pairs, let’s look at BU 452, a Sherburne Burnham pair. This little gem is in Lacerta at 2257.4+4301 and offers won-derful color contrast, but a tough magnitude spread: a 6.64 mag primary (deep orange) and a 10.54 rider (deep blue) just 6.7” away in PA 225. The colors are grand, but the great contrast will be a challenge. The Hipparcos program yielded different distances to each star: 570 and 37 light years.

The Difficult Pairs The most difficult of the three this month is an

Alvin Clark discovery, AGC 13. This tough little bugger is in Cygnus at 2114.8+3803 and offers very close sepa-ration with a pretty stark difference in magnitudes. The primary is 3.74 mag (white) while the pimple on its side is 6.65 mag (also white), just 0.7” away in PA 260 (as of 2006). It appears to be widening slowly so may be even wider than that now. This pair has an orbital solution(49.9 years) with maximum separation in 1972. There are 6 more very faint companions, but don’t worry about them. If you get AB, you’ve really done something!

STF 2854 is easier. Located in Pegasus (2204.4+1339), this challenger is made of two even stars (7.77 mag white and 7.97 white) just 1.5” apart, PA 85. The share common proper motion. In my notes, I state that at a weak 112x, I suspected duplicity as the image was oval! I got a very clean split at 560x.

The final challenge comes from STF 2881, in the


Being Double Minded

(Cont’d)

constellation of Pegasus. Sited at 2214.6+2934, it of-fers a 7.67 mag orange primary and an 8.32 mag buddy (also orange) 1.3” away in PA 78. With common proper motion, the pair is probably binary. I split it with an 8-inch SCT at 206x.

With the exception of the three Difficult pairs, all of these should be easy conquests in even moderate Arizona skies, so good hunting and sharp splitting! And if you get a rare and ultra steady night, go for the Diffi-cult pairs and see what your instrument (and eye) can do!

Contacting This Issue’s Authors

If you wish to write to an author if this month’s issue, complaining that they don’t know what they are talk-ing about or that they utterly dazzled you with their wordsmith skills, contact them by sending your mes-sage to the editor of Saguaro Skies, Richard Harshaw, at:

[email protected]

I will then forward your questions, comments or carping to the author who may (or may not) reply.

Dark Adaptation Curve from Martin Lewis of the Webb Society

(A torch is a flashlight for us Yankees; Ken Naiff knows what this is)

mailto:[email protected]


Board Members

President Chris Hanrahan ([email protected])

Vice-President Tom Polakis ([email protected])

Treasurer Mitch Prause ([email protected])

Secretary Paul Dickson ([email protected])

Properties Lynn Blackburn ([email protected])

Non-board Positions

Novice Group Leader Steve Dodder ([email protected])

Newsletter Editor Richard Harshaw ([email protected])

Webmaster Peter Argenziano ([email protected])

Public Events Jack Jones ([email protected])

ATM Group Paul Lind ([email protected])

Imaging Al Stiewing ([email protected])

Deep Sky Group A. J. Crayon ([email protected])

2011 SAC Officers and Contacts

Dates Days Site Sunset Twilight Ends Hours of Dark

October 1 Saturday Antennas 18:19 19:42 8:29

October 29 Saturday Antennas 17:45 19:09 9:04

November 25 Friday Antennas 17:27 18:55 10:54

SAC Dark of the Moon (DOTM) Star Parties for 2011

Star Dates, 2011

SAC Star Parties for 2011 (Third Quarter Moon)

Dates Days Site Sunset Twilight Ends Hours of Dark

September 24 Saturday Cherry Road 18:23 19:46 8:28

October 22 Saturday Saddle Mountain 17:51 19:14 9:14

November 19 Saturday Saddle Mountain 17:28 18:54 8:27

December 17 Saturday Saddle Mountain 17:27 18:56 7:23


Saguaro Skies Oct 2011 - Saguaro Astronomy Club 2011.pdf · September, 2011 Volume 35, Issue 7 ... also has Telrad, two 1.25 eyepieces ,and owners manual. ... The C-8 on a GEM Mount

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