Volume XVIII No. 5 February 2007 gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg Double Star Observation By Clif Ashcraft Double stars… We've all observed them. They are some of our favorite telescopic objects. Things we proudly show a visitor who has never looked through a telescope before: Albireo, Alcor and Mizar, Castor, the double-double epsilon Lyrae. Many are beautiful objects with lovely contrasting colors. Some are difficult resolution targets for testing the acuity of your vision or the resolving power of your telescope. How-ever, there's a lot more to double stars than this. They are a fascinating subject of scientific study and measurement going back to the beginnings of telescopic astronomy. The reason is simple: observation of a binary star system (a double star which is also a gravitationally bound physical system) is the only way to actually measure the mass of a star, and without the mass of a star one cannot do astrophysics. Everything about a star, its color, its energy output, even its lifetime, is dependant upon its mass. If we know the period of a binary's orbit we can calculate the sum of the masses of the two stars from Kepler's equations and if we have enough observations to truly define the orbits of both stars about their common center of gravity we can uniquely determine the mass of each star. For me, measuring double stars conjures an image of an 18th or 19th century astronomer peering up through the eyepiece of a filar micrometer (see Figure 1) attached to a classic refractor as he fiddles with precision screws adjusting the spacing and orienta-tions of delicate spider web crosshairs. For most of us this image comes from reading old astronomy texts. Mine comes from life, an event I experienced one late evening in February during the Mars opposition of 1963. I was taking the introductory astronomy course at UC Berkeley (a much needed vacation from my graduate research in chemistry) and had gotten the use of the historic 12" refractor at Lick observatory over the weekend for a student project to draw surface features on Mars. I had shut down the dome and given up for the night - winds were high and seeing was lousy. At least I had gotten some obser-vations, the professor with whom I had hitched a ride from the Berkeley campus up to Mt. Hamilton hadn't even been able to open the dome of the 120" reflector due to the high winds, and he had been waiting 6 months for his turn at the instrument. As I closed the door behind me, I heard faint music from the other end of the long hallway between the domes for the 12" and the 36" refractors. I walked down the hallway, timidly opened the door and looked in. There was the source of the music: a small stereo record player up against the wall of the dome room playing something glorious by Bach, and there, at the eyepiece of the micrometer of the 36" refractor was Dr. Van den Bos whom I had met earlier in the day at (Continued page 2: Double Stars) Double Stars (continued from page 1) By Clif Ashcraft the Lick cafeteria for staff and visiting astronomers. Intent on his work, he either didn't notice me or maybe politely ignored my intrusion as I softly closed the door and headed for the dormitory. This is what comes to my mind when I think of double star obser-vation. What does an astronomer actually do when a double star is measured? The most important measurements are the position angle (theta, ?) and separation (rho, ?) of the secondary star relative to the primary. As shown in Figure 2 below, the position an-gle is measured in degrees from north in a counter-clockwise direction (by way of the east) to the line be- tween the primary (A) and the secondary (B). The separation is the distance between the centers of A and B, measured in seconds of arc. The instrument that Dr Van den Bos was using when I blundered in was a filar micrometer. This instrument has two fixed spider webs at right angles to one another and an additional moveable web driven by a fine micrometer screw. A calibrated knob on the screw and a coarse scale inside the eyepiece measures the number of complete and fractional turns of the screw. The mechanism is mounted on an adjustable 360° protractor attached to the telescope, and a positive eyepiece is mounted on the optical axis behind the webs and focused on them to give a magnified view of the double star and the spider webs. To make a measurement, the whole instrument is rotated until the fixed web parallel to the micrometer screw axis is in the direction from A to B. The fixed crossed webs are then positioned on star A using the fine motion controls of the telescope. And finally, the moveable web is adjusted with the micrometer screw until it bisects the image of star B. When this is done, what one sees through the eyepiece is shown in the illustration at the above right. The separation of the parallel webs is read from the calibrated knob and the angle of rotation from the protractor. Here we would read a position angle of 217.4°, and a separation of 4.50 turns of the micrometer screw. Knowing the pitch of the screw and the focal length of the telescope allows one to calculate ? from the number of turns, and if the protractor had been previously lined up using star drift with the drive turned off to indicate which way west was (??= 270°), the angle of rotation of the instrument within the protractor gives the position an-gle directly. With practice, one can get quite good at this and make many double star measurements in an evening's session. I believe Dr. Van den Bos holds the record of 71,929 measurements, discovering 2895 new pairs - a record which is not likely to be sur-passed. While some double star observers still use the fi-lar micrometer today, other techniques have developed which take advantages of modern computer technology, CCD equipped astrocameras as well as advanced techniques such as speckle interferometry. Some "observers" even do it from the comfort of an armchair with a laptop browsing online databases us-ing tools such as Aladin . A couple of years ago, I became interested in doing more with double stars than just looking at them as a result of conversations with my friend Jim Daley of the Springfield Telescope Makers. This was shortly after I bought my SBIG camera, the ST2000XCM. This was a single shot color camera with an on-chip RGB filter matrix that I purchased for deep sky photography with my 12.5" Newtonian reflector. I soon learned that images taken with the camera could be used for double star measurements using the crosshairs tool in program CCDOPS that SBIG supplied with the camera. Unguided exposures of a few to 20 seconds duration sufficed to give measurable images of double stars down 14th magnitude. At the right is an image of 61 Cygni obtained with this camera. My experimental procedure was to take 10 to 20 images with the camera using a Barlow lens to provide sufficient image scale to resolve stars down to a few seconds of arc separation and then to use the crosshair tool in CCDOPS to measure the position angle and separation of the components of the double in each image. I then computed averages and standard deviations for all the data. The averaging deals with errors of position caused by atmospheric turbulence. (continued next page) Here is a typical set of measurements I obtained for twenty images of 61 Cygni (see Figure 3): ? = 150.70+/-0.26° and ? =30.84+/-0.24 sec. The WDS gives a separation of 31seconds and a position angle of 151 degrees for the last observation made in 2005. Not bad for a beginner. The other measurement made and reported by double star observers is the magnitude difference be-tween the components of the double star. Precise photometric measures of magnitude are difficult, requiring calibration of filters and photometric equipment, however, the brightness of one star relative to another is an easy and reliable measurement that can be done with CCD camera images and can even be estimated visually. The same crosshair tool in the program CCDOPS that I used to measure the position angle and separation of the components of 61 Cygni also gives a measure of their magnitudes. While the individual magnitudes cannot be trusted without calibration, the difference between the magnitudes measured on the same image is a reliable measure of their relative brightness. It also takes little additional effort once you have the images. For the set of 20 images of 61 Cygni I obtained a magnitude difference (so-called delta-m value) of 0.83+/-0.06 magnitudes. This was obtained without any additional filters, so it is an integrated white light delta-m obtained on a single shot color CCD through the on-chip RGB filter matrix. It is much preferred to make delta-m measurements through photometric filters (the UVBRI filter series). Since my CCD already had the RGB filters on individual pixels, this was impossible for me. I wanted to do it the right way, so I sent my camera back to Santa Barbara to have it upgraded to an ST-8 (just like the club's camera) with a non-anti-blooming CCD with no on-chip filters and also had it equipped with a 10 position computer operated filter wheel. I also bought the UVBRI filter set. The upgrade took about 3 months and cost me a bundle, but I am happy I did it. I have used the upgraded camera since August 2006 and have made 167 double star measurements (? ??? and delta-m through at least three of the photometric filters, usually V, R and I) in 2006 including 30 measurements on previously unreported doubles or new components of known doubles. These results have been written up in an article for the Journal of Double Star Observations and will probably appear in the spring 2007 issue. In spite of the bad weather I am off to a good start in 2007 with 27 measures so far, 6 on new systems or newly discovered components of known systems. I am concentrating my observing program on the WDS Neglected Doubles list . These are double stars that have been entered into the WDS database as a result of a report at the time of their discovery and sometimes a few early measures were made and reported, but have been neglected ever since. Some of these have been observed only once or twice in the last hundred or so years. Many are considered lost since no double is seen at the reported coordinates. Some turn out to be dust specs on old photographic plates, others just mislaid through incomplete recording of the coordinates by the discoverer or data compiler. Some are optical doubles where one component has a large proper motion and has gone its way and left its "partner" behind so the pair doesn't look like a double anymore. They are the lost sheep, the orphans of the double star realm. Recovering the lost doubles is a fascinating detective game involving searching the skies as well as online star catalogs and the journals in which the original data was published. A good example of this is D 33. What is D 33 you ask? Well, double star observers have their private lingo just like everyone else. D 33 is a discover designation. The D refers to Baron Ercole Dembowski , an Italian astronomer who observed from an observatory in (continued page 8: Double Stars) Teaching Creation in a One Room Schoolhouse by Bonnie B. Witzgall Being a teacher or the purveyor of information is not an easy job. There are basic assumptions the teacher makes about the students and then begins the class from there. It's even harder to teach others to become good teachers themselves and continually spread the high-quality information. In today's electronic world, the sharing of data requires more skills, knowledge and preparation. One needs to be comfortable with the new electronic devices and be educated on how to manipulate those modern machines. To convey information to a computer savvy audience, a blackboard with chalk or finger paints on a cave wall won't do the trick. I saw a serious problem at Sperry Observatory. Many talented people had interesting subjects to share, but they did not know how use the new technology. The Displays & Presentations Committee always welcomes more people to lecture and present topics on Public Friday nights at Sperry Observatory. The devices of choice are the laptop and video projector, but not everyone knows how to use them. I woke up one morning and wanted to advance these AAI members from composing lectures on manual typewriters to using the new fangled methods. On a whim, I decided to hold an AAI class at Sperry Observatory for learning the basic points of PowerPoint. (Gasp! - what was I thinking!) The first step was to advertise the proposed course. Some members were free on a weekday eve-ning while some were hungry for some new e action on a Saturday night, therefore, each Thursday ses-sion is being repeated on Saturday. To encourage enrollment, I promised that everyone who attended the class would learn something that they did not know before. The result was overwhelming! Between phone calls, e mails, and being approached at Sperry, I was surprised by how many members were interested in learning PowerPoint. Even people who had a background in using the Microsoft program were eager to learn a new technique. I had committed myself to teaching the creation of PowerPoint in the equivalent of a one room schoolhouse and to making this class a success for all attendees. (It was daunting.) There were all levels of attendees with different agendas. Young AAI members like Rachel and Aaron learned this PowerPoint skill in school. They never lived in a world without cell phones, digital cameras or .com companies. Several senor AAI members were apprehensive, but willing to learn a modern process. Joanne realized her a laptop lacked a PowerPoint program. She ran to the nearest computer store to buy a Microsoft Office package just for the sake of taking my class! (Wow! I felt honored!) Like anything else, this new electronic world needs a power source. Among the power strips, extension cords for the laptops, the club's coffee urn and tabletop speakers, it was quite a spaghetti mess throughout the observatory. Ah, but just think of what was happening… knowledgeable people were using portable computers to create individual astronomical presentations. It was like a Star Trek setting. (It was great!) As advertised, I began my class slowly and emphasized this was a basic course. Everyone would learn the straightforward steps to build a simple display from scratch, regardless of previous training. The AAI students owned different levels of the PowerPoint program running on laptops of various capability. Many members possessed different stages of PowerPoint knowledge, either derived from their jobs, shown by family members or were self taught. It was my task to reach them all and help them fly together. As the classes progressed, it became clear that being a teacher affected many of my own personal levels, too. I had to speak loudly to reach the students sitting in the back of the room, as there were no empty seats in the classroom area. I sat at the right end of the front table while projecting the images from Al W's computer onto the big screen. There were (continued next page) much pointing, verbal descriptions and hand gestures. Then I had to physically run from laptop to laptop and help 'locate' the lost member who had gone astray in a confusion of photons. Many of the AAI'ers, like Meghan and Neil who knew PowerPoint would lean over and help the slightly confused stu-dent sitting in the next seat. (That was encouraging and useful for me.) As a requirement for the class, I told the twenty-five students they must produce only five slides, with two being the Title and Summary slides. Their subjects should be astronomical or scientific, but the special effects in their shows were personal choice. To help the effort, Al W. and I distributed printouts of my PowerPoint introduction, lists of shortcut keys, PPT websites and disks of astro-images for each student's use. After showing the class all the basics of PowerPoint, I saved the best for last. The comprehension of PowerPoint special effects seems to bring out the best (worst?) in people's wild creativity. I braced for such a raucous onslaught and the class did not dis- appoint. There were squeals of delight and laughter coming from people who never realized PowerPoint could be such fun! Al Z. played with 'applause' sound effects. Judith declared that Clif was out of control. Ray looked for a special sound bite on the Web and found one. He used the distinctive noise of a flushing toilet to accompany 'who knows which' astronomical photo. (Honestly, I was afraid to look.) Mike rotated his Title slide in a counterclockwise spin, noting he was going to give this talk in the Northern Hemi-sphere. Charlie kept losing his Title slide, but I kept finding it. Steve C. changed the title of his "Acknowl-edgements" slide to ".and I Blame It On…" Hank and Mary donated a big book on PowerPoint 2003 for everyone's reference. Members Wayne and Dave, who were PowerPoint novices, quickly got the hang of the assignment. They became amused at what they created and grinned profusely. Both Paul and Gordon declared they were learning things they had not even noticed before. (That's wonderful!) Did I bother assigning more homework to this crazy class? All AAI members are volunteers and have real jobs outside of Sperry Observatory. This course is personally important to them and to me, but if no one gets the 'hang' of PowerPoint, nothing happens! As of this writing, only Ray showed his PowerPoint project to the class. Everyone else is still playing, inventing and experimenting with their newfound (Continued page 10: Creation) Finally! A Total Lunar Eclipse!! An Impatient Observers' Guide By A.P. Witzgall The long wait is finally over - a total lunar eclipse is coming! After a 3 year drought, on March 3rd, 2007, the Moon will rise in eclipse, and the entire totality will last over 70 minutes. We haven't had a total lunar eclipse since October, 2004. For the newcomers to astronomy and to AAI, this is a potential grand event. This article will tell you what to expect, how to ob-serve it with the proper equipment, and how to docu-ment what you will see. See an excellent diagram of lunar eclipse geometry at Fred Espenak's MrEclipse.com website ( http://www.mreclipse.com/ ). It shows a simplified view of how eclipses of the Moon occur. This same website gives us the detailed geometry of totality, and where on Earth it is best seen. Here in North Amer-ica, and especially on the East Coast, we have per-haps the best view. First, the nuts-and-bolts. On March 3rd, the Sun will set at 5:49 pm EST. The Moon, at Full phase, will rise at 5:43pm. It's one of rare times that you get to see the geometry of lunar phases, as Full Moon occurs when the Sun is directly opposite the Moon, relative to Earth. The schedule of events for the eclipse is shown in table 1 (page 9). The totally eclipsed Moon will rise in the deepening twilight, and this will probably hamper our ability to see the first twenty minutes of totality. The Moon is north of the center of the umbra, or dark shadow of the Earth, for some 74 minutes, so we do get to see the last twenty minutes in a rather dark sky. If it's really clear, as it was back on November 18th, 1975, we may see the northernmost part of the eclipsed Moon first. As a special bonus, look to the eclipsed limb to watch 5th magnitude 59 Leonis pass behind the still-darkened section of the Moon. You need only binocu-lars to see this occultation. This should be exciting to see; the last time I can recall performing occultation timings was back in 1992, with the stars of Taurus in the background to a very dark Moon (the ring of light from the Sun passing through the atmosphere which usually illuminates the eclipsed disc was greatly di- minished by dust from the 1991 eruption of Mt. Pi-natubo). (Continued page 10: Eclipse) Clearing the Neighborhood by Jeremy P. Carlo Let's define a parameter (Greek letter mu), which is defined as the mass of the putative planet divided by the total mass of all other objects within its orbital annulus: A large would correspond to a "true" planet, traveling in a relatively clear orbit, with nothing sub-stantial in size relative to the planet in the orbital path. A small , on the other hand, indicates that the putative planet is surrounded by a substantially larger amount of debris and is thus not worthy of planethood status. is called the "planetary discriminant" and was proposed by Alan Stern and Steven Soter. Below is a table (adapted from Ref. 1) estimating the values of in descending order for the nine planets plus a num-ber of proposed planetary objects: Earth makes a strong showing, with the highest of all the planets, while Mars and Neptune take a per-formance hit from roving asteroids and KBOs. But note that the eight planets from Mercury through Nep-tune all have values of that are in the range of 5,000 to over a million. On the other hand, the five additional objects I included (the two largest aster-oids, Ceres and Pallas, the two largest trans-neptunian objects Pluto and Eris, plus Pluto's moon Charon) all have values of < 1. If you were forced to draw a cutoff line, you'd draw it between Mars and Ceres, between which a drop in by a factor of nearly 100,000 is observed. (Just beyond the bottom of the table are a host of ob- jects with 0.01 and less, consisting of the large asteroids and trans- neptunian objects, so there's no second sharp cutoff.) Thus Mercury through Neptune have relatively "clear" orbits, while the latter objects do not. Mercury through Neptune thus qualify as planets, whereas the remaining objects do not. I should note that an accurate determination of depends on knowing how much "stuff" is contained within the orbital annulus, which is quite uncertain in the case of Eris, and not determined accurately in the cases of Pluto and Charon. However, the uncertain-ties are far smaller than the four orders of magnitude required to bump either Pluto or Eris into the "planet" category, so aside from some jostling among the bot-tom ranks, no change is going to occur. Now, one could argue that the IAU definition states that a planet must have cleared its neighbor-hood. However, just because an object orbits in a "clear" annulus doesn't mean it was responsible for that clearing. Is there another parameter that meas-ures how effectively a planet is (theoretically) able to clear its orbit? A parameter (lambda) was proposed by Alan Stern and Harold Levison, and is defined as = M2 / P Here M is the proposed planet's mass (in units of the Earth's mass), and P its orbital period (in years). (continued next page) represents how effectively a planet is able to clear its neighborhood of debris through gravitational interactions. The more massive the planet, the stronger its gravitational influence and the more effec-tive it is in sweeping out its area. It turns out that this effectiveness is proportional to M2. And the larger the orbit (or equivalently, the less frequently the planet visits a given sector of its orbit), the longer it takes to clear the area, so P appears in the denominator. has an empirical advantage over in that it only requires knowledge of an object's orbital period (ac-curately known in all cases) and its mass (known to high precision in all the above cases except Ceres, Vesta, and Eris, whose masses are still well-constrained). Once again we can construct a table (adapted from Ref. 1) in descending order of values of (set up so that Earth = 1): This gives a more expected result, with massive Jupiter holding its place as "king of the planets," and, after that, a roughly descending mass-ordered list (Venus and Uranus finish ahead of the slightly more massive Earth and Neptune, respectively, because of the latter's larger orbits to clear). And again there is a clear jump (five orders of magnitude) between the same eight "planets" and the five additional non-planets included. Neither parameter lends any support for Pluto planethood. In fact Pluto isn't even the first runner-up! According to , Eris is the leading candidate among the non-planets, while lends that title to lowly Ceres. But in either case there is a 4-5 order-of-magnitude gap that needs to be breached by any planetary con-tender, and current observational uncertainties permit nowhere near that large a jump. Clearly, there are eight objects which belong in the "planet" category according to both discriminants dis-cussed. And there are additional objects, foremost among them the five objects listed in the tables above, which belong to one or more separate catego- ries. Perhaps it makes more sense, as Clif Ashcraft suggested, to have multiple non-planet categories for rocky and icy dwarfs, for example, but what is clear is that Pluto and the other proposed planetary contend-ers do not meet the same criteria as the "classical" planets. 1. Steven Soter. What is a planet? Astronomical Jour-nal 132, 2513-2519, 2006. Available at http://tinyurl.com/wgfto Double Stars (continued from page 3) By Clif Ashcraft Naples and later Gallarate using a 7" refractor for his later work. He made tens of thousands of micrometer measures of double stars, won the Royal Astronomi-cal Society's Gold Medal and has a crater on the moon named after him. The 33 is simply a serial number from a catalog of Dembowski's discoveries. D 33 is in fact a double star that the good Baron discov-ered on August 8, 1867. It was recorded in early lists of double stars and eventually was incorporated into the WDS where I found it with the notation that it had not been observed since 1868, a typical neglected double. The WDS identifier 21510+6139 for this star encodes its approximate coordinates, 21h51.0m RA, +61°39' declination. I use Guide to help me find things in the sky. Navigating it to the WDS coordi-nates for D 33, I found a double star close enough to the WDS coordinates that it was within the outlines of my CCD chip plotted on the screen (a nice feature of Guide), however, Guide informed me that this double was STT 451, a discovery by Otto Struve in 1847 and certainly one which would have been known to Dem-bowski. Also, the characteristics of STT 451 (? = 218°, ? = 4.1") did not remotely match what Dem-bowski reported for D 33 (? = 131°, ? = 3.2"). I pointed my telescope to this location, and sure enough, STT 451 was there. Even though STT 451 is not a neglected double (last measure in 2002), I took a set of 12 images anyway (4 through each of V, R and I filters) for later measurement using the crosshair tool, and to add my "mote" to the accumulating cloud of data for STT 451. I then "looked around" in the vicinity using my CCD camera in its "focus mode" which generates a continuous sequence of still images but is practically a "live" view of the sky. About 2.5 minutes of RA west of the field containing STT 451 and a bit north of ST451, was a triple star, the AB pair of which looked suspiciously like what Dembowski had reported. I moved my field of view in Guide to the same location and found that this was a known triple star called MLB 176, WDS position 21485+6137, discovered by W. Milburn in 1920. The WDS data for MLB 176AB (? = 131°, ? = 3.4") were practically dead on for D 33. Component C was con-siderably fainter and could easily have been missed by Dembowski. I took another set of 12 images for later measurement. It was clear to me that MLB 176AB just had to be D 33. Somehow the coordinates that got entered into the early catalogs that were compiled into the WDS must be wrong. I emailed Dr. Brian Mason, the USNO director of the WDS and told him my concerns and asked if there were any way we could find Dembowski's original observations? A few hours went by and an email from the USNO appeared in my mailbox with an attached PDF file. It was a facsimile of page 375 in Baron Dembowski's privately published journal of double star observations. See Figure 4. There I found an entry with the cryptic heading "? Ad ?S 451". A footnote to the entry reads (in Italian): Trovata da me li 8 Agusto 1867. Precede ?S 251 di circa 2m ed é piu boreale circa 2'. I figured out that the cryptic heading probably meant that the new dis-covery was to be located by difference (?) from the coordinates of OS 451. OS (or ?S in Greek letters) are Otto Struve's initials (that's STT in WDS discov-erer code). My very rusty Italian translates the foot-note as follows: Discovered by me on August 8, 1867. Precedes OS 251 (an obvious misprint, a script 4 is easily mistaken for a 2 if the down stroke is light) by about 2 minutes (i.e., about 2 minutes to the west) and more north by about 2 minutes. The entry itself gives three filar micrometer measures of the position angle and separation of the double. Brian really came through for me. Dr Brian Mason is the director of the WDS at the US Naval Observatory and is very sup-portive of amateur astronomers working in the field of double star measurement. (continued next page) He is both a mentor and a great source of difficult to find information. It thus appears that when D 33 was tabulated into the early double star catalogs, someone neglected to offset the right ascension of STT 451 by Dembowski's differential description "precedes OS 451 by about 2 minutes" but did add 2' to the declination. When you do it properly you get 21490+6139. This is quite close to 21485+6137 for MLB 176, easily within the same low power telescope field. The effect of my identifica-tion of D 33 with MLB 176AB will probably lead to a couple of small changes in the WDS. I expect D 33 to get an AB added to it to become D 33AB with correct coordinates supplied, and for MLB 176AB and sub- sequent measures of it to be reassigned as later measures of D 33AB, but for MLB 176AC to be kept as Milburn's discovery. Note that later discoveries of additional components to a multiple star system get the initials and serial number of the discoverer, but receive the same WDS identifier showing they are part of the same system. I have several findings of this sort in my observations for 2006. They will ap-pear in future editions of the WDS as ACA xx. So far xx ranges from one up to about 36. I have a long way to go to catch up with either of the Struves, Dem-bowski or Van den Bos, but it's a start. I find double star observation to be an interesting and rewarding astronomical activity, one where I am sure that my efforts will have an impact and become useful to future astronomers. It is also something we could do as a club. We have the ST8 camera already, and either of our two telescopes would be excellent in-struments to use with it to do imaging and measure-ments of double stars. The US Naval Observatory Double Star center abstracts data from the JDSO, so my measures (and AAI's if we go this way) will be in-cluded in the database along with those of William Herschel, John Herschel, F.G.W Struve, Otto Struve (the obsession runs in families), and of course Dr. Van den Bos and many, many others. Nice set of col-leagues to have… Total Lunar Eclipse March 3rd Table 1. event time (EST) Partial eclipse begins 4:30 pm (below horizon) Total phase begins 5:44 pm (just risen!!) Mid-eclipse 6:20 pm Total phase ends 6:58 pm Partial phase ends 8:12 pm Moon exits penumbra 8:49 pm Creation (Continued from page 5) freedom in slide creation. That's OK. Volunteerism is a 'funny' thing. When the situation is no longer fun, the unpaid helper ceases to volunteer. My official reason to hold this class was to educate the AAI membership in PowerPoint and crate a larger lecture pool for Friday night public presentations. The personal and confidential reason of mine to teach PowerPoint was to help people learn a new skill using the new medium for their use whether they are at home or away from the Observatory. My proud students can now enter the brave new world of e presentations and enlighten everyone about AAI and astronomy. Dare I schedule another PowerPoint class later in the year to taint more members with unbridled creativity and silly grins? I don't think the Displays & Presentations Committee would mind. (…and even though it's a lot of work and noisy bustle, I wouldn't mind, either.) Eclipse (continued from page 5) Now, how do you observe a total eclipse of the Moon? Actually rather casually! You've got some 75 minutes to watch the changing shades of gray and red as the Moon crosses the dark central shadow of Earth, and even with the twilight handicap, it's still gonna give us at least 40 minutes of dark-sky view-ing. Dress warmly, as though it were 20 degrees colder than the weather channels will say. Remember to keep your head covered! Layer you sweater under a good heavy coat. Wear insulated boots, or at least a thick wool sock with a thin cotton sock over it in or-dinary boots. This is no time for fashion! We want to be comfortable as we observe, not frozen and shiver-ing! Shivering means blurred photos!! Your equipment for viewing can be as simple as your unaided eyes, or as complex as a full scale as-trophotographic array! Binoculars are favored by most visual observers, as you get a good view of the Moon with some background stars. Use a tripod for best results. Even a small telescope can yield a spectacu-lar view. Larger telescopes at low power can see fine detail on the lunar surface that is usually drowned out at Full phase. For the astrophoto crowd, I like to use a C-8 with a telecompressor to get a focal ratio of f/6.3, which gives me a disc on the negative or slide of about 11 mm diameter, which is nice to fit onto a slide or print. I use ISO 400 to 800 Fujicolor for prints, and ISO 400 Ektachrome for slides. As each eclipse is unique in lighting and therefore brightness (the 'inconstant Moon' of Shakespeare applies!), the best I can tell you on exposure is simply to bracket them. During a dark totality, at ISO 800, start from ˝ second and work up to 8 seconds. If it's a bright red disc that rises, start at 1/8 second at the same speed, and go up to 4 seconds. For those with the new digital SLRs (lucky guys/gals!), this is a great opportunity to break new ground. I can tell how new a technology is just by re-searching its use for a given purpose through the cur-rent literature. Believe me, there's very little in print at this time when it comes to lunar eclipse photos and digital SLRs! Ditto for webcams. See what your cam-era meter says for exposure, and give it a try. If you keep getting underexposures, increase the ISO rating (or go up and down several steps from the 'nominal' exposure it suggests). Remember, you'll have at least 40 minutes to capture any number of good and bad exposures, so if some don't work, you can delete them and go for a longer or shorter exposure. Maybe this will be the first 'digital lunar eclipse' in the ama-teur astronomy community! The next total lunar eclipse will take place in the early morning hours of August 28th, 2007, when 'the setting Moon bids us a fond farewell into the west' (and the umbra of Earth's shadow) for those of us on the East Coast. The next one after that, on Thursday, February 21st, 2008, is going to be a spectacular event, as it will give everyone in North and South America a great view, from start to finish, penumbra to penumbra! We on the East Coast will have a ring-side seat for a dark eclipse in a dark late evening sky. For this upcoming event, on March 3rd, I wish all of us clear skies and good seeing that Saturday night! Stunning Beauties of the Solar System by Dr. Ken Kremer The image of Bottomless Bay and Cape St. Mary shown in the pictorial supplement was captured by the Pancam imaging team led by Cornell University Prof. Jim Bell. (see full resolution image at http://tinyurl.com/3ch7q7 ) Contact me if interested in purchasing an "autographed" copy of Prof Bell's beautiful new book titled "Postcards from Mars". Last month's stunner from Mars, "Gusev at Sun-set" was just chosen as the most popular rover pic-ture in an online poll organized by the Jet Propulsion Lab (JPL). Over 10,000 people voted. The full results and choices are at: http://tinyurl.com/t22jx Please contact me for further information or public outreach presentations. My next public talks are: Rittenhouse Astronomical Society (RAS) in the Franklin Institute: Philadelphia, PA, Wed Feb 14, 8pm. "Mars, Saturn, Comets and Beyond (in 3-D)". http://tinyurl.com/258nmc Raritan Valley Community College Planetarium: Somerville, NJ, Tue Mar 27, 7:30pm. "Touring Our New Solar System (in 3-D)". http://www.raritanval.edu/planetarium/ Dr. Ken Kremer NASA JPL Solar System Ambassador Email: kremerken@yahoo.com MEMBERSHIP DUES Regular Membership: $21 Sustaining Membership: $31 Sponsoring Membership: $46 Family Membership: $5 Sky & Telescope: $32.95 Astronomy subscription: $34 First Time Application Fee: $3 Dues can be paid in person to Mem-bership Chair or Treasurer, or by mail to: AAI, PO Box 111, Garwood, NJ 07027-0111 DR. LEW'S SEMINARS Some of the topics for upcoming seminars include: " Details of Lunar Eclipses " How do we launch a synchro-nous satellite? " How do we send a vehicle to Mars? FRIDAYS AT SPERRY February 23, 2007 Optics 1: Reflection, Refraction, Prisms, Thin and Thick Lenses, New Developments Dr. Lew Thomas March 2, 2007 Spectroscopy in Astronomy Barry Malpas March 9, 2007 PowerPoint Demos Bonnie Witzgall's students DOME DUTY SCHEDULE Mar. 2 Team D Mar. 9 Team E Mar. 16 Team A Mar. 23 Team B Mar. 30 Team C EMAIL CONTACTS editor@asterism.org Editor of The Asterism Ray Shapp, Acting Editor Deadline for submissions to each month's newsletter is the first Friday of that month. membership@asterism.org AAI Membership Chair trustees@asterism.org All three Trustees of AAI ray@asterism.org Ray Shapp for the website exec@asterism.org Executive Committee All schedules above were accurate at time of publication. Please check www.asterism.org for latest informa-tion (click on "Club Activities") (Choice of topic at Dr. Lew's seminars is determined by participants' interest) Theater In The Sky by Ron Ruemmler March 2007 belongs to the Moon. Not only do we have two eclipses, but our natural satellite has such close conjunctions with two bright stars and Saturn that it actually passes over them five times. Unfortu-nately, none of these occultations is visible from North America. The solar eclipse is only partial and not visible from North America except for the last few minutes around sunset near Nome, Alaska. The lunar eclipse, however, is very interesting. Since totally starts at sunset in New Jersey, finding the Moon in bright twilight will be a challenge. Spotting the deep orange or brown Moon against the blue sky should be very memorable. It's been over 28 months since the last total lunar eclipse, but the one this month is the first of three in less than a year. After that there will be another dry spell of 34 months until the next one. Whenever a month has two eclipses you can be sure that the quarter moon between them will be very high or very low. This month the Last Quarter Moon is so low it passes below Antares, the southernmost bright star in the Zodiac. Conversely, the First Quarter Moon is so high it approaches Pollux in Gemini, the northernmost Zodiac constellation. Note that both conjunctions between the Moon and Regulus come 24 hours after lunar conjunctions with Saturn. That's because the angular distance between the star and the planet is a close match to the 12 de-grees that the Moon covers in a day. MARCH SKY CALENDAR 1 Thu 7:00 PM Saturn lower right of Moon; occulta-tion visible from Europe 2 Fri 7:00 PM Regulus upper right of Moon; occulta-tion visible from Mongolia 3 Sat 4:30 PM Partial Lunar Eclipse begins (not visi-ble from New Jersey) 3 Sat 5:42 PM Moonrise 3 Sat 5:44 PM Total Lunar Eclipse begins 3 Sat 5:50 PM Sunset 3 Sat 6:17 PM Full Moon 3 Sat 6:21 PM Deepest Eclipse 3 Sat 6:58 PM Total Lunar Eclipse ends 3 Sat 8:12 PM Partial Lunar Eclipse ends 5 Mon 11:00 AM Uranus passes beyond the Sun into the morning sky 11 Sun 2:00 AM Daylight saving time begins; turn clocks forward one hour 11 Sun 6:00 AM Moon far lower right of Jupiter 11 Sun 6:00 AM Moon just lower left of Antares; oc-cultation visible from Patagonia 11 Sun 11:55 PM Last Quarter Moon 12 Mon 6:00 AM Moon far lower left of Jupiter 15 Thu 6:00 AM Crescent Moon far right of Mars 16 Fri 6:00 AM Thin crescent Moon lower left of Mars and right of Mercury 17 Sat 6:30 AM Very thin crescent Moon lower left of Mercury 18 Sun 10:43 PM New Moon; Partial Solar Eclipse visible from central Asia 19 Mon 3:00 PM Moon nearest to Earth (perigee); expect high tides 19 Mon 7:40 PM Extremely thin crescent Moon far lower right of Venus 20 Tue 8:07 PM Vernal Equinox; Spring begins 20 Tue 8:30 PM Thin crescent Moon lower right of Venus 21 Wed 8:30 PM Crescent Moon above Venus 21 Wed 10:00 PM Mercury at maximum elongation from the Sun 25 Sun 2:16 PM First Quarter Moon 26 Mon 11:00 PM Moon just below Pollux 28 Wed 11:00 PM Moon just above Saturn; occulta-tion visible from Greenland 29 Thu 11:00 PM Moon just upper left of Regulus; occultation visible from Scandinavia Stunning Beauties of Our Solar System by Ken Kremer Pictorial Supplement We are living in a golden age of space exploration with a steady stream of beautiful images which are not only rich in visual detail, but often also illustrate a bit of previously undiscovered science. In my role as a NASA So- lar System Ambassador, I am excited by each day's beauties as they arrive in my inbox. Here for your enjoy-ment is this month's small sampling of images that caught my attention. Methane Lakes on Titan Image is about 84 miles across. Photo Credit: NASA/JPL/USGS http://photojournal.jpl.nasa.gov/jpeg/PIA09102.jpg Pictorial Supplement (continued) by Ken Kremer Springtime at Victoria: Bottomless Bay and Cape St. Mary In January, both Spirit and Opportunity roved into their 4th year of science operations on the Red planet, more than 11 times beyond the pre-launch "warranty" of 90 Sols (or Martian days). And the good news is that springtime arrives on Mars on 8 February, which translates into rising power levels and thus further ad-ventures for the intrepid and fairly healthy twin sisters. In early January however, Spirit's life was seriously threatened by a sudden dust storm causing a power crisis. So the team literally took emergency action by quickly interrupting a science gathering campaign and drove her to a north facing slope to soak up solar en-ergy. Now, all is well and she is heading back to the mysterious feature nicknamed "Home Plate", which may be an eroded volcano. The link to this image can be found below at the Pancam website of the rover imaging team leader, Cornell University Prof Jim Bell. Click on it to enlarge this mosaic to full resolution and see the rover wheel tracks on the Martian surface, just left of center at top. Contact me if interested in purchasing an "autographed" copy of Prof Bell's beautiful new book titled "Postcards from Mars". http://marswatch.astro.cornell.edu/pancam_instrument/1037B_bottomless_bay.html Pictorial Supplement (continued) by Ken Kremer Uncover another Stunning Beauty from MRO in this month's Pictorial Supplement ! And watch for the Rosetta Comet chaser mission from the European Space Agency (ESA) which will fly past Mars for a gravity assist on 25 Feb. She reveals a stunning view of Mars and the Milky Way at: http://www.esa.int/SPECIALS/Rosetta/SEMNRESMTWE_1.html#subhead1 Last month's stunner from Mars, "Gusev at Sunset" was just chosen as the most popular rover picture in an online poll organized by the Jet Propulsion Lab (JPL). Over 10,000 people voted. The full results and choices are at: http://marsdata1.jpl.nasa.gov/gallery/photoContest/index.cfm Please contact me for further information or public outreach presentations. My next public talks are: Rittenhouse Astronomical Society (RAS) in the Franklin Institute: Philadelphia, PA, Wed Feb 14, 8pm. "Mars, Saturn, Comets and Beyond (in 3-D)". http://www.rittenhouseastronomicalsociety.org/ Raritan Valley Community College Planetarium: Somerville, NJ, Tue Mar 27, 7:30pm. "Touring Our New Solar System (in 3-D)". http://www.raritanval.edu/planetarium/ Dr. Ken Kremer NASA JPL Solar System Ambassador Email: kremerken@yahoo.com Pictorial Supplement (continued) by Ken Kremer Titanian Mountain Range Pictorial Supplement (continued) by Ken Kremer Comet McNaught: First Light from STEREO-B Pictorial Supplement (continued) by Ken Kremer Jupiter as seen from Mars Orbit Space News Alert: The New Horizons Spacecraft will perform a gravity assisted flyby of Jupiter later this month on 28 Feb 2007 to pick up 9,000 MPH velocity for its long journey to Pluto while simultaneously con-ducting an extensive science campaign of the Jovian system. The spacecraft's long range camera (LORRI) is already targeting Jupiter and producing fantastic rotation movies. More Jovian Stunners will be revealed in full color as part of next months "Beauties".