Vol. 56, No. 10, December, 2011
Next Meeting – December 20th, 2011 at 8:00 PM ~ ANNUAL HOLIDAY PARTY!! ~ at the Mt. Cuba Astronomical Observatory ~ Please Join Us for Fellowship and Fun ~
FROM THE PRESIDENT Bill Hanagan First off, I’d like to thank DAS member Ron Worden Annual Holiday Party to Feature for his November presentation on Backyard Astronomy with a GIANT SWAP MEET... Your Observatory, Greg Lee for the November “What’s Up”, and Fred DeLucia for describing the observing challenge of Got Some Astro-Stuff That Rediscovering Comet P/2006 T1 Levy. I’d also like to thank everyone who brought refreshments to the November meeting. You’d Like to Sell or Trade? Our December meeting will feature a Swap Meet, Bring it to the Annual Xmas Party! “What’s Up in the Sky” by Greg Lee, a brief slide show of Longwood Gardens’ Christmas Decorations at Night, by yours truly, and our traditional Christmas/Holiday Party. I The DAS December Swap Meet realize that many DAS members can’t make it out to our Bill Hanagan December celebration, so at this point I would like to extend In past years, only a handful of people have brought to everyone the warmest of Holiday Greetings and my items in for sale at our swap meets. For a swap meet to heartiest wishes for a Happy New Year. work, a lot more people need to bring items in for sale. For those of you who can attend our Christmas Please look through your astronomy gear and pull out the celebration, we will be setting up for both the Swap Meet and items you don’t use or don’t have space for anymore, figure the Christmas Party starting at 7:00 PM. There will be no out what you want for them, and bring them in for sale! board meeting in December. Note that the Swap Meet will Maybe someone else can use them and you can recover be temporarily suspended at 8:00 PM when we move into part of your cost and clear a little space for something new! the lecture room for the announcements and presentations, Even if you don’t sell an item, it may spark someone’s but it will resume after the presentations and continue during interest in another aspect of amateur astronomy. the Holiday Party. Several of our members have volunteered to bring As always, I’d like to remind you to keep thinking tables for everyone’s use during the swap meet, so there will about how YOU can contribute to the DAS and how you can be ample table space available for many DAS members to make the DAS a better astronomy club. While we’ve had display their items. Of course, if you need a lot of display some volunteers step forward, and we’ve received a variety of (continued on page 2) donations, more volunteers and donations are needed. A club works best when essentially all of its able- FOCUS uses plenty of photos bodied members pitch-in and help out at our club functions in each Issue... in whatever way they can. If you want to make the DAS a we want to use YOURS...not Hubble’s!! better astronomy club, give me a call at 302-239-0949. I’m PLEASE email to FOCUS editor [email protected]. sure we can come up with something that you can do to help the DAS that also suits your particular interests. Each issue of FOCUS is full of useful hyperlinks. Just click on any graphic or telltale blue web address and your browser should take you to additional linked web resources. Saturn - Photo by DAS Member Rob Lancaster taken at the May 21st AP SIG meeting at Mt. Cuba. Taken using Bill Hanagan’s Aprochromatic Refractor on Rob’s Losmandy G11 mount. Images were captured from live view movies using a Canon Digital Rebel Xsi and stacked & processed using Lynkeos.
Observing with the Delaware Astronomical Society...
DAS Member Star Parties Bill Hanagan I used a tripod mounted Canon 50D DSLR at ISO NEW We held our fifth MSP of the year at the Elk River site on November 18. The seeing was a little better than 1200 with a 50mm f/1.8 average and transpar- lens set at f/2 for a 10 ency was good overall, second exposure. The though we saw some resulting image was thin clouds drift past for adjusted for color bal- a few minutes. ance, contrast and The red-light photo brightness. The Orion at left shows Rob nebula is visible as a Lancaster tweaking the small glow around the focus on his Canon central star in Orion’s 60D DSLR as he sword hilt. With a half- prepares to acquire an frame APS-C DSLR such image of Jupiter. Rob’s as the Canon 50D or image of Jupiter with 60D, a 50mm lens the shadow of Europa transiting will appear in a future issue frames a narrow area and of FOCUS. acts like a short focus telephoto lens. Trailing is barely Later in the evening the constellation of Orion visible in this photo and would become obvious in exposures climbed high enough to allow me to take the photo at right. longer than 10 seconds. (continued at the bottom of page 9)
NEW The DAS December Swap Meet (continued from pg. 1) and sizes, lenses, finders, telescope mounts, tube rings, space you may want to bring an extra table along. eyepieces, Barlow lenses, focal reducers, planispheres, Try to have each of your items clearly labeled in astronomical CCD cameras, Digital Single Lens Reflex advance with an initial asking price. Naturally, you can (DSLR) cameras, film based SLR cameras, camera lenses, change the price later if you choose. In the end, the selling tripods, mirror making supplies, telescope parts, books and price is the price that the buyer and seller agree on. DVDs on astronomy, astro-photos, astronomy posters, and What sort of items are we looking for at the Swap calendars. Less obvious items might include a film SLR Meet? Astronomy items! That includes any item that’s camera (Swap Meet items often include older technology), useful for visual observing, astronomical imaging, or tele- cable releases, a video camera, a web-cam (especially a scope making, as well as any item with an astronomy Philips or other CCD based webcam), low light security theme. Obvious examples include telescopes of all types cameras, a laptop computer, or even cold-weather gear.
“PUBLIC NIGHTS” at the Mt. CUBA OBSERVATORY...
MCAO PUBLIC NIGHTS Greg Weaver nights at 8pm. Please check the website for programs planned, full details and updates. The Mt. Cuba Observatory Public The remaining Public Nights schedule for Nights continue year 2011 follows. The 2012 schedule has not yet been posted. Date Speaker Topic round! In addition to learning about many Dec. 12 D. Wilson Wonders of the Universe aspects of the heavens, you’ll have a chance to visit and view our all-digital full-dome planetarium. You can pick up a schedule when you next come to a meeting or get the latest updated version off the website at: http:// MountCuba.org. Programs are presented on Monday
-2- DAS Special Interest Groups for Photography and Telescope Construction...
DAS ASTROPHOTOGRAPHY NEW The next AP SIG meeting is tentatively scheduled for SPECIAL INTEREST GROUP Bill Hanagan Saturday, January 14 at 7:30 PM at MCAO. I also wish to proudly announce that February will The DAS astrophotography special interest group (DAS mark the TEN YEAR anniversary of the founding of the AP AP SIG) meets on Friday nights at 7:30pm every other month at Mt. SIG at the Delaware Astronomical Society! Cuba regardless of weather. The SIG also meets for photo shoots scheduled on 1-2 day notice to synchronize with the weather. Even if you aren’t an AP-SIG member, you’re wel- The monthly meetings are informal and typically come to attend to learn more. Be sure to sign up for the include the presentation of astrophotos taken by the members DAS Yahoo Group in order to receive the email announce- along with an extended question and answer period. Objects ments that provide directions and dates of the meetings. commonly photographed include constellations, auroras, lunar As always, please consider submitting one or more of eclipses, and planetary photos, as well as a wide variety of deep- your favorite astrophotos for publication in the FOCUS. A sky objects such as nebulae, galaxies, star clusters, etc. The recent photo is not required. You can email your photo(s) as topics discussed cover the entire gamut of astrophotography, .jpg files to our FOCUS editor, Joe Neuberger at his address at from how to get started with a minimum of equipment, to polar [email protected]. Please include a text file briefly aligning your telescope, all of the way to the fine points of using describing how you made each photo (in Microsoft Word auto-guiders and post-processing digital images. format) along with any by-lines or captions you would like Joe You can get started in astrophotography with just to use. If you would like, you can write a more in-depth your current camera mounted on a tripod or a motorized discussion to go with your photos. Joe can make a masterful telescope by taking wide field photographs of meteor showers, layout, but if you would like to suggest a layout of your own conjunctions, constellations, and star trails. As you move to you can insert copies of your photos into the Word document progressively fainter and smaller subjects, you’ll need better to give him an idea what you would like to see. Either way, equipment. Joining the AP SIG is a great way to learn what don’t forget to attach a high resolution .jpg file to your email for equipment you’ll need and what works well before you spend each photo. Joe has done a great job improving the look of the your money. If you are interested in joining the AP SIG, just FOCUS and adding relevant links to take advantage of the fact email your name, address, and phone number to me at that the FOCUS is now on-line, but like all newsletter editors, [email protected]. he needs as much material as he can get from club members.
DAS. AMATEUR TELESCOPE MAKING SPECIAL INTEREST GROUP Bill Hanagan The DAS Amateur Telescope Making (ATM) Special email their name, address, and phone number to me at Interest Group (SIG ) meets on evenings and weekends [email protected]. according to the availability of the members and the particu- Meeting dates are announced primarily by email, so lar projects that are underway. Currently the ATM SIG has a if you are interested in telescope making, be sure to let medium Dob building program under way. The general range me know! of activities of the ATM SIG includes all manner of telescope making, mirror making, and the making of accessories for The refiguring of the club’s 17.5” f/4.5 mirror is telescopes and observing. proceeding. If you would like to participate in this effort, Anyone interested in joining the ATM SIG should please let me know.
LOANER TELESCOPES and SAWIN OBSERVATORY REMINDER Tom Sidowski One of the best advantages of being a member of the The DAS also maintains a club observatory on the grounds Delaware Astronomical Society is that all members have the of the Mt. Cuba Astronomical Observatory. The Sawin Observatory privilege of being trained to use and then borrow equipment houses the club’s permanently mounted 12.5" reflecting telescope owned by the club for personal use. Currently, we have two and a 17.5" Coulter Odyssey 2 Dobsonian telescope. They are for scopes available for loan: a Celestron 8" Schmidt-Cassegrain, the use of club members once they are trained and checked-out in and a 6" Orion Sky-Quest XT6 Dobsonian reflector. The loan is a simple operating procedure. Members who are interested in for at least a month. If you’re interested in checking out either becoming key holders of the Sawin Observatory should contact me of these scopes, contact Tom Sidowski at 302-239-1844. at 302-239-1844 to arrange for training in the use of the facility.
NEW The PRESIDENT’S DAS BOARD MEETING AGENDA for DECEMBER Note: there will be no Board Meeting in December . to allow time for setting up the Holiday Party and Swap Meet Tables. So, arrive early with your STUFF! -3- Notes on the Member Star Parties (MSPs) Bill Hanagan For each MSP cycle there are usually four potential dates designated in advance, but which of these is used for the event is “flex-scheduled” according to the weather using the DAS Yahoo Group email system. Please be sure to mark your calendars with the potential MSP dates that appear in the table! Obviously, you need to keep as many of these dates open as possible so when a GO announcement is made you’re in a position to attend the DAS Member Star Party regardless of which date the weather favors! The DAS has a core group of visual observers and astro-imagers who travel to Tuckahoe, Cherry Springs, West Virginia, and other dark sky sites as opportunities and the weather allow. If you’re interested in going along or meeting up on any of the road trips mentioned in the MSP schedule, let me know and I’ll fill you in on the details and keep you apprised as plans develop. Several potential road trips are listed on the schedule. Road trips require that several DAS members commit to going in advance should the weather prove favorable for both nights. When the weather forecast only looks good for one night, the MSP will often be redirected to a closer site such as the Elk River site or the Sawin observatory. While DAS members who go on road trips are often involved in both observing and imaging, these road trips are particularly valuable for visual observers because they offer the best opportunity to see deep sky objects through large aperture telescopes under dark skies. Long-time members of the DAS may remember the disappointing views they had looking through Mount Cuba’s 24” Tinsley Cassegrain telescope. Don’t let the bad views produced by that telescope affect your thinking about what can be seen through a large aperture telescope. Most of today’s big Dobs produce dramatically superior visual images thanks in part to better optics, the use of a “thin” primary mirror, and fans for controlling thermal problems. If you are truly interested in visual observing, you owe it to yourself to see first-hand what dark skies and a large aperture will allow you to see. Finally, I’d like to remind you that you need to be signed up for the DAS Yahoo Group to receive the scheduling announcements for the MSPs. A full description of the MSP program appears on the DAS website at http://delastro.org/ and in the December 2009 issue of the FOCUS.
-4- -5- Mars - Photo Credit: by DAS Member Rob Lancaster. Photo taken on March 18, 2010.
MEMBERSHIP EXPIRATION NOTICES DAS FORUM / E-MAIL SITE ON YAHOO Bill McKibben Don Shedrick If you receive the FOCUS by email, you will be This is a restricted e-mail service for use by DAS notified of your membership renewal by email. If you receive members for DAS purposes. To use this site, go to http:// the FOCUS in the mail and the mailing label on the envelope groups.yahoo.com; search for Delaware Astronomical containing your FOCUS is marked with red marker, your Society; and click on the link that comes up. To join, you membership is expiring or has expired. Please see the must have a Yahoo ID and password; if you don’t, you can renewal form at the end of the FOCUS for additional renewal register at this time by following Yahoo’s instructions. You information. Also see the “Magazine Subscriptions” section will then be allowed to “Join the group” upon clicking in that in the FOCUS for information about subscription renewal. box. You must then register for the DAS group and add your profile by clicking on “add new profile” and completing the form. When adding or editing your profile, you will need to LIBRARY NEWS Glenn Bentley enter your actual name in the “Real Name” box so you can be Members are invited to drop by the library during the NEW identified as a DAS member so Don Shedrick can approve your Holiday Party to peruse our shelves for holiday fireside application to join the DAS group, and everyone will know to reading materials. Unfortunately, I will not be attending. but whom they are communicating. you just have to fill out the information on the clipboard, Finally, specify your desired email address for delivery located on the shelf, if you find something you want to of messages. Note: you may choose to not have your name borrow. Happy Holidays to all, and to all a safe and prosper- and email address displayed to anyone other than DAS ous new year. members who are members of the Yahoo DAS email group. For more detailed instructions, go to the DAS ASTRONOMICAL LEAGUE MEMBERSHIP website under DAS Resource Links. DAS members have the opportunity to become members in the Astronomical League at the discounted rate MAGAZINE SUBSCRIPTIONS Bill McKibben of $7.50 per year. Benefits include the Reflector (a quarterly newsletter), observing programs, awards, discounts on books SKY & TELESCOPE will be processed by the club and educational materials. For questions on joining the for the first subscription year only. The publisher should then Astronomical League, contact Lynn King at meetings, call send renewal notices directly to the subscriber at the club rate 302-764-8816 or email [email protected]. of $32.95. The subscriber can then pay the publisher directly. NOTE: If you receive a renewal notice for an amount other than $32.95, check to see if there are any special MT. CUBA LENDING LIBRARY Paul Stratton offers included in the rate. Also check the renewal date printed on the magazine address label. These ‘special May I first extend a hardy thanks to all of those offers’ are likely to occur several months prior to the renewal using the Lending Library. Your interest has made this a date. However, if you are approaching your renewal date and rewarding effort. have not received the correct renewal notice, contact me and BOOK OF THE MONTH--PLANETS FOR MEN I will process the renewal through the club. by Stephen H. Dole and Isaac Asimov ASTRONOMY will continue to be processed by the The Kepler Telescope has now found many hundred club for all subscription years. planets in the Milk Way system. The data being collected is Please see the renewal form at the end of the indicating that some of these may very well be inhabitable FOCUS for additional renewal information. by humans. May I quote. “ In the course of millions of years the human species has adapted itself to the narrow ranges of temperature and air pressure, the availability of food and water, the chemical and physical components of our earthly environment.. Now that means are at hand to transcend this enviroment, the question arises: Where else in the universe can such physical conditions be found?” Read PLANETS FOR MEN and let the thoughts begin. -6- ASTRO-PHOTO of the Horsehead Nebula MONTH Photo Credit: DAS Member Rob Lancaster
“This is the Horsehead Nebula taken at the November Star Party with my 60D through my 10 inch Newtonian telescope with several stacked 5 Minute exposures.” --Rob
Photo taken Nov., 2011
WEBSITE of the MONTH http://www.galex.caltech.edu/index.html The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope observing galaxies in ultraviolet light across 10 billion years of cosmic history. A Pegasus rocket launched GALEX into orbit at 8 a.m. EDT on April 28th, 2003. Although originally planned as a 29-month mission, the NASA Senior Review Panel in 2006 recommended that the mission lifetime be extended.
GALEX’s observations are telling scientists how galaxies, the basic structures of our Universe, evolve and change. Additionally, GALEX observations are investigating the causes of star formation during a period when most of the stars and elements we see today had their origins.
Led by the California Institute of Technology, GALEX is conducting several first-of-a-kind sky surveys, including an extra- galactic (beyond our galaxy) ultraviolet all-sky survey. During its mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing us closer to understanding how galaxies like our own Milky Way were formed.
GALEX is also identifying celestial objects for further study by ongoing and future missions and GALEX data now populates a large, unprecedented archive available to the entire astronomical community and to the general public.
Scientists would like to understand when the stars that we see today and the chemical elements that make up our Milky Way galaxy were formed. With its ultraviolet observations, GALEX is filling in one of the key pieces of this puzzle. Check out their incredibly extensive website by clicking on the links above.
-7- Three Holiday Meteor Showers for Observing Enjoyment Greg Lee Geminids – Dec 13,14 The second of the two best annual meteor showers, the Gemnids, will peak before dawn on Wednesday morning, December 14. But the moon is just past full and will wash out all but the brightest meteors, just as it did for the Perseids back in August. But this only means that there’s no need to get up early to observe when the radiant is highest. You will likely see just as many meteors this year at more convenient hours before the moon gets too high on Tuesday the 13th and even on Wednesday, the 14th. There are debris streams before and after the usual peak which sometimes develop into a new peak. And since the Geminids are known to have outbursts up to 100 Zenith Hourly Rate it’s worth checking this shower before 9 pm on Tuesday and before 10 pm on Wednesday. Even in moonlight later in the evening the brighter meteors may number 20-25 per hour. Ursids – before dawn Dec 23 (night of Dec 22) The North American Meteor Network (NAMN) and International Meteor Organization (IMO) are calling for more observations of this under-observed shower. It normally produces only about 10 meteors per hour (barely more than the average sporatic rate of 7 per hour) but spikes up to 50 has been reported in recent years and it suspected that other outbursts may have been missed because few observers make an effort to send in reports of this minor shower. This year the moon will allow favorable observing conditions so more reports are hoped for. You can make a contribution to science by submitting reports of your observations. Visit the online Electronic Visual Report Form of the IMO at http://www.imo.net/visual/report/electronic. The radiant is very close to the “Guardian Stars” in the bowl of the Little Dipper. Quadrantids – peak 2 am Jan 4 (night of Jan 3) Another cold weather shower that doesn’t get much attention is the Quadrantids. This is surprising because observers from dark sites have counted 120 per hour. That’s an average of two per minute! And that’s worth bundling up for. The name comes from the obsolete constellation Quadrans Muralis (the Mural Quadrant) which occupied the area between the present day constellations of Ursa Major, Bootes, Hercules, and Draco. Looking NE about 2 am the radiant is under the Big Dipper near the top of Bootes. Meteor observing doesn’t require a telescope or any optical aid. All you need is your own dark-adapted eyes and some patience. This is one area where amateurs still provide most of the observations used by scientists.
T1 Levy Proves an Elusive Target Fred Delucia As for our attempts to observe P/2006 T1 Levy, the short version is that it was a no show... at least for Frank Collisimo, Shawn Collier and myself at the Blue Mountain Vista Observatory’s Observation Field. Frank had his 18" f4.5 setup with his mallicam and a 4" refractor finder scope, Shawn had his 16" Meade SCT and I had my 18" f/4.3 Star Structure. According to our charts we were dead on where it should’ve been. What we did see was a faint edge-on galaxy that we were staring at on Frank’s Mallincam display wondering if it was T1 Levy but was actually LEDA 2052629, a 17.7 magnitude galaxy that I later found in Skytools3 on the chart exactly where we were looking. Other exciting and well detailed DSOs on the same display were: NGC 2419, a rather faint globular through my 13mm Ethos that came through exceptionally well in the Mallicam, plus the Crab, NGC 891, NGC 2024 (aka The Flame Nebula), M74, NGC 2683, M82, NGC 2903, and of course NGC 7331 (so as to target the area for T1 Levy) which showed excellent dust lanes and spiral structures. One of the real kicker views of the night was the Horsehead Nebula in Frank’s 4" refractor. That’s not a typo. It was there and without a H-Beta filter. OK, it did have a whole lot of help with his Mallincam. Seeing was in and out from average to poor making it predominately a night for DSOs. I started off binoviewing the near 1/4 Moon with my 16mm Naglers and a #25 red filter. I find that the #25 red gives me a good balance between reduced glare and enhanced detail and is my preferred filter for lunar observing over the usual 13% Moon filter. As I scanned down the terminator I came upon Julius Caesar crater. Its collapsed eastern wall and wrinkled lava floor was so well detailed that I easily imagined the impact event creating the lava that flowed out that wall. Other notables through a single eyepiece (in no particular order of observing) were Cleopatra’s Eye, NGC 40 and at 251x with my Explore Scientific 9mm 100° ep NGC 2158 the cluster companion of M35. The night was absolutely cloudless right up through the time I drove off the field at 3AM and all the way home. An enjoyable and rewarding night, nonetheless, even without the elusive T1 Levy. -8- 2011 MSP Annual 4th “On-Site” AP SIG Program Wrap-Up Bill Hanagan Meeting Held Bill Hanagan First, I’d like to take this opportunity to thank the DAS members who The Astrophotography Special Interest Group (AP-SIG) met on have served as MSP supervisors or who have otherwise contributed to the Friday, December 3 in the fourth and last of the “on-site” series of AP-SIG success of the MSP program during 2011. Greg Lee, Bill McKibben, Gus meetings being held this year. This time the meeting was held at the Sawin Swartout, and myself have all helped out by acting as MSP supervisors. Gus observatory and I acted as host. deserves our special thanks for making the Elk River Dark Sky Site available to Rick Davis, Rob Lancaster, Jeff Lawrence and I all attended and were treated to some excellent views of Jupiter as well as a rare chance to us, even on nights when he couldn’t make it out himself. The Elk River site has obtain data at a time when the seeing was 4/5 for several consecutive hours. been a valuable addition to our repertoire of observing sites. I’d also like to thank I started off by demonstrating my technique for acquiring Don Shedrick, who organized and continues to manage the DAS Yahoo Group. planetary image data, which I’ll describe later, using Jupiter as the subject. As we conclude the second year of the Member Star Party Rob Lancaster also demonstrated planetary imaging using his new Canon (MSP) program, it’s worth reflecting on how the program has worked. In 60D DSLR, which can record video images directly to its internal memory card. the previous year, we were able to hold 8 MSPs. So far, in 2011 we’ve After acquiring a large amount of video data, the meeting moved been able to hold 5 MSPs and we have a good chance of holding another into the MCAO library for some hot chocolate and cookies and for a on December 16 or 17. demonstration of the freeware program “Registax 6”, which was created The number of MSPs held this year was held down by two major specifically for processing planetary image data. factors: 1) more than 20% of the potential MSP dates for 2011 could not be The image below was produced from data obtained during the used due to conflicts with Holiday weekends and 2) it has been an exceptionally meeting. North is up and Jupiter’s surface features rotate from left to right in this view. The Great Red Spot (GRS) has just rotated into view and can be seen in wet and cloudy year in the East. Even before we were visited by Hurricane the Southern Equatorial Belt (SEB) near the extreme left hand edge of Jupiter. Irene, we had nearly twice as much rainfall in August than in any other August Note also the prominent barge (an unusually dark area which is often elongated) since record keeping began in the late 1800’s. With the weather we’ve had, it’s in the Northern Equatorial Belt (NEB), located just to the left of the meridian. somewhat surprising that we were able to hold 5 MSPs in 2011. The credit for To acquire the data for the image, I used my Canon 50D DSLR this goes to “Flex-Scheduling” using the DAS Yahoo Group email, which made equipped with a T-ring and a 2” T-adapter mounted in a 2x Televue Big this possible by allowing us to schedule our MSPs on short notice to take Barlow, which in turn was mounted in the focuser of the Sawin 12.5” advantage of the very few nights of good weather that came along. If we had Newtonian telescope. A laptop computer connected to the 50D was employed still been setting firm star party dates months in advance, it’s quite likely that all but to collect video image data using the freeware program “EOS Movie Record” 1 or 2 would have been rained out or clouded out. running under Windows XP SP3. It’s worth noting that four out of the five MSPs held this year, or After the meeting, I visually 80%, were held “on the road” at Tuckahoe and Elk River. A higher selected the best 200 out of 600 frames from one of the data sets using the percentage of MSPs were held on the road this year in part because the freeware program “VirtualDub”. I weather was especially bad during the winter when we commonly hold our did the alignment, stacking, and other MSPs in the Sawin observatory. Even so, holding MSPs “on the road” has processing of the best 200 frames become the norm rather than the exception, particularly during the prime using Registax 6. Registax 6 can observing months in the spring and fall. automatically choose “the best” frames, There are good reasons why the MSPs are held “on the road” but in my view it does a mediocre job most of the time. For one, all of our destination sites allow our members to at this. I find that I get a better final drive their vehicles onto the observing field so they can set up their often image if I eliminate most of the worst rather large and heavy telescopes next to their vehicles. Going “on the road” images visually using VirtualDub and then use Registax for everything else. also allows us to hold MSPs in conjunction with nearby multi-night regional star parties, specifically the Delmarva Stargazer’s spring and fall “Stargaze” DAS Member Star Parties (continued from pg 2) Star Parties. Further, going “on the road” puts our MSPs at darker observing Temperatures fell from the mid 40’s into the 30’s over the course sites where the large majority of MSP attendees actually want to observe. of the evening, but everyone was comfortable in their winter gear. Even Several potential MSP dates in the 2011 schedule were so, we took a break to enjoy a cup of hot chocolate in Gus’s cabin. designated for possible road trips to more distant locations like the Cherry In the photo below, Rob is setting up his CCD auto-guider for some Springs and Ricketts Glenn State Parks in Pennsylvania. These more deepsky imaging. distant sites require two consecutive nights of good weather to make the Everyone had a great extra travel worthwhile. Unfortunately, this year’s unusually poor weather time. Thanks go out to Gus Swartout, prevented that from happening, so these particular MSPs were either who made his Elk River Cabin and rescheduled on a single night at a location closer to home or cancelled site available for DAS use. outright for lack of a clear night. Even so, there is strong interest in multi- The last two potential MSP night MSPs at primordially dark sites among our core group of observers. dates for the year are December 16 With a little luck, the weather next year will allow us to hold an MSP at a site and 17. Greg Lee will be the MSP like the Cherry Springs State Park (in PA) or perhaps at Spruce Knob (in VA). supervisor this time around. Looking forward to 2012, Greg Lee has volunteered to oversee The mechanics of the MSP the scheduling of our MSPs and to make arrangements with other members program are described separately to act as MSP supervisors. The mechanics of the MSP program, including under “Notes on the Member Star flex-scheduling via the DAS Yahoo Group email, will remain the same. The Parties (MSPs)” on page 4. 2012 MSP schedule appears on pages 4 and 5 of the FOCUS.
-9- NASA Orbiter Catches Mars Sand Dunes in Motion Nov. 17, 2011: PASADENA, Calif. — Images from NASA’s Mars Reconnaissance Orbiter show sand dunes and ripples moving across the surface of Mars at dozens of locations and shifting up to several yards. These observations reveal the planet’s sandy surface is more dynamic than previously thought. “Mars either has more gusts of wind than we knew about before, or the winds are capable of transporting more sand,” said Nathan Bridges, planetary scientist at the Johns Hopkins University’s Applied Physics Laboratory in Laurel, Md., and lead author of a paper on the finding published online in the journal Geology. “We used to think of the sand on Mars as relatively immobile, so these new observations are changing our whole perspective.” While red dust is known to swirl all around Mars in storms and dust devils, the planet’s dark sand grains are larger and harder to move. Less than a decade ago, scientists A rippled dune front in Herschel Crater on thought the dunes and ripples on Mars either did not budge or moved too slowly for detection. Mars moved an average of about two meters (about two yards) between March 3, 2007 and MRO was launched in 2005. Initial images from the spacecraft’s High Resolu- December 1, 2010. Image credit: NASA/JPL- tion Imaging Science Experiment (HiRISE) camera documented only a few cases of Caltech/Univ. of Ariz./JHUAPL shifting sand dunes and ripples, collectively called bedforms. Now, after years of Click above for Full image and caption monitoring the Martian surface, the spacecraft has documented movements of a few yards (or meters) per year in dozens of locations across the planet. The air on Mars is thin, so stronger gusts of wind are needed to push a grain of sand. Wind-tunnel experiments have shown that a patch of sand would take winds of about 80 mph (nearly 130 kilometers per hour) to move on Mars compared with only 10 mph (about 16 kilometers per hour) on Earth. Measurements from the meteorology experiments on NASA’s Viking landers in the 1970s and early 1980s, in addition to climate models, showed such winds should be rare on Mars. The first hints that Martian dunes move came from NASA’s Mars Global Surveyor, which operated from 1997 to 2006. But the spacecraft’s cameras lacked the resolution to definitively detect the changes. NASA’s Mars Exploration Rovers also A rippled patch of sand in Becquerel Crater on Mars moved about two meters (about two detected hints of shifting sand when they touched down on the Red Planet’s surface yards) between November 24, 2006 and in 2004. The mission team was surprised to see grains of sand dotting the rovers’ September 5, 2010. Image credit: NASA/JPL- solar panels. They also witnessed the rovers’ track marks filling in with sand. Caltech/Univ. of Ariz./JHUAPL “Sand moves by hopping from place to place,” said Matthew Golombek, a co- Click above for Full image and caption author of the new paper and a member of the Mars Exploration Rover and Mars Reconnaissance Orbiter teams at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Before the rovers landed on Mars, we had no clear evidence of sand moving.” Not all of the sand on Mars is blowing in the wind. The study also identifies several areas where the bedforms did not move. “The sand dunes where we didn’t see movement today could have larger grains, or perhaps their surface layers are cemented together,” said Bridges, who also is a member of the HiRISE team. “These studies show the benefit of long-term monitoring at high resolution.” According to scientists, the seemingly stationary areas might move on much larger time scales, triggered by climate cycles on Mars that last tens of thousands of A rippled dune front in Herschel Crater on Mars years. The tilt of Mars’ axis relative to its orbital plane can vary dramatically. This, moved an average of about one meter (about one combined with the oval shape of Mars’ orbit, can cause extreme changes in the Martian yard) between March 3, 2007 and December 1, climate, much greater than those experienced on Earth. Mars may once have been 2010. Image credit: NASA/JPL-Caltech/Univ. of Ariz./ JHUAPL Click above for Full image and caption warm enough that the carbon dioxide now frozen in the polar ice caps could have been free to form a thicker atmosphere, leading to stronger winds capable of transporting sand. HiRISE is operated by the University of Arizona in Tucson. The instrument was built by Ball Aerospace & Technologies Corp. of Boulder, Colo. The Mars Exploration Rovers Opportunity and Spirit were built by JPL. JPL also manages the Mars Recon- naissance Orbiter and Mars Exploration Rover projects for NASA’s Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver is NASA’s industry partner for the Mars Reconnaissance Orbiter Project and built the spacecraft. JPL is managed for NASA by the California Institute of Technology in Pasadena. MRO images and additional information is available online at: http:// www.nasa.gov/mro and http://mars.jpl.nasa.gov/mro/ The eastern margin of a rippled dune in Herschel Crater For more information about NASA Mars missions, visit the Web at: on Mars moved an average distance of three meters www.nasa.gov/mars. (about three yards) between March 3, 2007 and December 1, 2010. Image credit: NASA/JPL-Caltech/Univ. of Ariz./ Authors: Dwayne Brown, NASA Headquarters, Washington, [email protected] and JHUAPL Click above for Full image and caption Priscilla Vega, Jet Propulsion Laboratory, Pasadena, Calif., [email protected]
-10- Lunar Reconnaissance Orbiter Camera Team Releases High Resolution Global Topographic Map of Moon
Nov. 16, 2011: The science is about 30 km (18 miles) team that oversees the there is complete overlap all imaging system on board the way around the moon in NASA’s Lunar Reconnais- one month. The orbit-to-orbit sance Orbiter (LRO) has WAC overlap provides a strong released the highest stereo effect. Using digital resolution near-global photogrammetric techniques, a topographic map of the terrain model can be computed moon ever created. from the stereo overlap. This new topo- The near-global graphic map, from Arizona topographic map was State University in Tempe, constructed from 69,000 shows the surface shape WAC stereo models and and features over nearly the covers the latitude range entire moon with a pixel 79°S to 79°N, 98.2% of the scale close to 100 meters entire lunar surface. Due to (328 feet). A single mea- persistent shadows near the sure of elevation (one pixel) poles it is not possible to is about the size of two foot- create a complete stereo ball fields placed side-by-side. based map at the highest Although the moon latitudes. However, another is our closest neighbor, instrument onboard LRO knowledge of its morphol- LROC WAC color shaded relief of the lunar farside. (Credit: NASA’s called LOLA excels at ogy is still limited. Due to Goddard Space Flight Center/DLR/ASU) › Click above for Larger image mapping topography at the instrumental limitations of › Related story and imagery from Arizona State University poles. Since LOLA ranges to previous missions, a global map of the moon’s topography at the surface with its own lasers, and the LRO orbits converge high resolution has not existed until now. With the LRO Wide at the poles, a very high resolution topographic model is Angle Camera and the Lunar Orbiter Laser Altimeter (LOLA) possible, and can be used to fill in the WAC “hole at the instrument, scientists can now accurately portray the shape pole.” The WAC topography was produced by LROC team of the entire moon at high resolution. members at the German Aerospace Center. “Our new topographic view of the moon provides the “Collecting the data and creating the new topographic dataset that lunar scientists have waited for since the Apollo map was a huge collaborative effort between the LRO project, the era,” says Mark Robinson, Principal Investigator of the Lunar LOLA team, the LROC team at ASU and in Germany at the DLR,” Reconnaissance Orbiter Camera (LROC) from Arizona State says Robinson. “I could not be more pleased with the quality of the University in Tempe. “We can now determine slopes of all map – it’s phenomenal! The richness of detail should inspire lunar major geologic terrains on the moon at 100 meter scale. Deter- geologists around the world for years to come.” mine how the crust has deformed, better understand impact Shaded relief images can be created from the GLD100 crater mechanics, investigate the nature of volcanic features, and by illuminating the “surface” (in this case the shape model) from better plan future robotic and human missions to the moon.” a given Sun direction and elevation above the horizon. To Called the Global Lunar DTM 100 m topographic convey an absolute sense of height the resulting grayscale model (GLD100), this map was created based on data pixels are painted with colors that represent the altitude. acquired by LRO’s WAC, which is part of the LROC imaging Visualizations like these allow scientists to view the surface system. The LROC imaging system consists of two Narrow from very different perspectives, providing a powerful tool for Angle Cameras (NACs) to provide high-resolution images, interpreting the geologic processes that have shaped the moon. and the WAC to provide 100-meter resolution images in The LRO spacecraft is managed by NASA’s seven color bands over a 57-kilometer (35-mile) swath. Goddard Space Flight Center in Greenbelt, Md., for NASA’s The WAC is a relatively small instrument, easily Science Mission Directorate in Washington. fitting into the palm of one’s hand; however, despite its Future versions: The current model incorporates the diminutive size it maps nearly the entire moon every month. first year of stereo imaging; there is another year of data that Each month the moon’s lighting has changed so the WAC is can be added to the solution. These additional stereo images continuously building up a record of how different rocks will not only improve the sharpness (resolution) of the model reflect light under different conditions, and adding to the but also fill in very small gaps that exist in the current map. LROC library of stereo observations. Also the LROC team has made small improvements to the The LROC (WAC) has a pixel scale of about 75 camera distortion model and the LOLA team has improved our meters (246 feet), and at the average altitude of 50 km (31 knowledge of the spacecraft position over time. These next miles) a WAC image swath is 70 km (43 miles) wide across generation steps will further improve the accuracy of the next the ground-track. Since the equatorial distance between orbits version of the LROC GLD100 topographic model of the moon. -11- Mystery of the Lunar Ionosphere Nov. 14, 2011: How can a world without air have an iono- sphere? Somehow the Moon has done it. Lunar researchers have been struggling with the mystery for years, and they may have finally found a solution. But first, what is an ionosphere? Every terrestrial planet with an atmosphere has one. High above the planet’s rocky surface where the atmosphere meets the vacuum of space, ultraviolet rays from the sun break apart atoms of air. This creates a layer of ionized gas—an “ionosphere.” Here on Earth, the ionosphere has a big impact on communications and navigation. For instance, it reflects Click above to view a ScienceCast video radio waves, allowing shortwave radio operators to bounce about the Moon’s puzzling ionosphere. transmissions over the horizon for long-range communica- tions. The ionosphere also bends and scatters signals from Stubbs and colleagues realized that floating dust GPS satellites, sometimes causing your GPS tracker to could provide the answer. UV rays from the sun hit the grains mis-read your position. and ionize them. According to their calculations, this pro- The first convincing evidence for an ionosphere cess produces enough charge (positive grains surrounded by around the Moon came in the 1970s from the Soviet probes negative electrons) to create the observed ionosphere. Luna 19 and 22. Circling the Moon at close range, the An ionosphere made of dust instead of gas is new to orbiters sensed a layer of charged material extending a few planetary science. No one knows how it will behave at tens of km above the lunar surface containing as many as different times of night and day or at different phases of the 1000 electrons per cubic centimeter—a thousand times solar cycle, or how it might affect future radio communica- more than any theory could explain. Radio astronomers also tions and navigation on the Moon. NASA’s ARTEMIS probes found hints of the lunar ionosphere when distant radio (orbiting the Moon now) and the LADEE spacecraft (sched- sources passed behind the Moon’s limb. uled to launch in 2013 specifically for the purpose of studying The idea of an “airless Moon” having an ionosphere the lunar exosphere) may yet reveal its habits. didn’t make much sense, but the evidence seemed compelling. Updates may be As a matter of fact, the Moon isn’t quite as airless expected in less than as most people think. Small amounts of gas created by 40 years. radioactive decay seep out of the lunar interior; meteoroids The original and the solar wind also blast atoms off the Moon’s surface. research reported in The resulting shroud of gas is so thin, however, that many this story was pub researchers refuse to call it an atmosphere, preferring lished in the October instead the term “exosphere.” The density of the lunar 2011 edition of Plan- exosphere is about a hundred million billion times less than etary and Space that of air on Earth—not enough to support an ionosphere as Science: Stubbs, T.J., dense as the ones the Luna probes sensed. D.A. Glenar, W.M. Dust grains floating above the lunar surface For 40 years, the Moon’s ionosphere remained a Farrell, R.R. Vondrak, are ionized by solar UV radiation. M.R. Collier, J.S. mystery until Tim Stubbs of the Goddard Space Flight Center [Click for larger images: #1, #2] published a possible solution earlier this year. The answer, Halekas, and D.T. he proposes, is moondust. Delory (2011), On the role of dust in the lunar ionosphere, Stubbs—a 30-something scientist who wasn’t even Planetary and Space Science, 59, 1659-1664, doi: 10.1016/ born when the Moon’s ionosphere was discovered—read the j.pss.2011.05.011. accounts of Apollo 15 astronauts who reported seeing a Author & Production Editor: Dr. Tony Phillips | Credit: Science@NASA strange glow over the Moon’s horizon. Many researchers For More Information: believe the astronauts were seeing moondust. The Moon is NASA Mission to Study the Moon’s Fragile Atmosphere — an extremely dusty place, naturally surrounded by a swarm Science@NASA Dead Spacecraft Walking — Science@NASA of dust grains—think PigPen in Charlie Brown. When these Earth’s Magnetotail Lashes the Moon — (Science@NASA) floating grains catch the light of the rising or setting sun, Moon Storms — (Science@NASA) they create a glow along the horizon. Moon Fountains — (Science@NASA) ARTEMIS — mission home page -12- New Evidence for Liquid Water on Europa Nov. 16, 2011: In a potentially significant finding in the The recent analysis suggests chaos features on search for life beyond Earth, scientists studying data from Europa’s surface are formed by mechanisms that involve NASA’s Galileo probe have discovered what appears to be a significant exchange between the icy shell and the underlying body of liquid water the lake. This kind of “chaos” volume of the North may provide a pathway for American Great Lakes transferring nutrients and locked inside the icy shell energy between the of Jupiter’s moon Europa. surface and the vast global The water could ocean already thought to represent a potential exist below the thick ice habitat for life, and many shell. Researchers believe more such lakes might this would increase the exist throughout the potential for life there. shallow regions of ”This new under- Europa’s shell, say standing of processes on researchers writing in the Europa would not have journal Nature. been possible without the “The data opens foundation of the last 20 up some compelling years of observations over possibilities,” said Mary Earth’s ice sheets and Voytek, director of NASA’s floating ice shelves,” said Astrobiology Program at Don Blankenship, a co- agency headquarters in author and senior research Washington. “However, scientist at the Institute for scientists worldwide will Geophysics, where he A new study of data from the Galileo probe suggests Great Lake-sized want to take a close look bodies of water exist in the icy shell of Europa. Photo credit: Britney Schmidt/ leads airborne radar studies at this analysis and re- Dead Pixel FX/Univ. of Texas at Austin [Click picture above for video] of Earth’s ice sheets. view the data before we The authors have can fully appreciate the implication of these results.” good reason to believe their model is correct. Still, because The Galileo spacecraft, launched by the space the inferred lakes are several miles below the surface, the shuttle Atlantis in 1989, provided scientists decades of data only true confirmation of their presence would come from a to analyze before the probe plunged into Jupiter’s atmo- future spacecraft mission designed to probe the ice shell. Such sphere in 2003. One of the most significant discoveries was a mission was rated as the second highest priority flagship the inference of a global salt water ocean below the surface mission by the National Research Council’s recent Planetary of Europa. This ocean is deep enough to cover the whole Science Decadal Survey surface of Europa and contains more liquid water than all of and is being studied Earth’s oceans combined. However, being far from the sun, by NASA. the ocean surface is completely frozen. Most scientists think For more images this ice crust is tens of miles thick. and a video animation of ”One opinion in the scientific community has been if the findings, visit the the ice shell is thick, that’s bad for biology. That might mean University of Texas at the surface isn’t communicating with the underlying ocean,” Austin website by said Britney Schmidt, lead author of the Nature paper and clicking here. postdoctoral fellow at the Institute for Geophysics, University Prod. Editor: Dr. Tony Phillips | Thera Macula (false color) is a region of of Texas at Austin. “Now, we see evidence that it’s a thick Credit: Science@NASA ice shell that can mix vigorously and new evidence for giant likely active chaos production above a large liquid water lake in the icy shell of Europa. shallow lakes. That could make Europa and its ocean For More Information: more habitable. Galileo was the first spacecraft to directly measure ” Schmidt and her team focused on Galileo images Jupiter’s atmosphere with a probe and conduct long-term of two roughly circular, bumpy features on Europa’s surface observations of the Jovian system. The probe was the first to fly called chaos terrains. Based on similar processes seen on by an asteroid and discover the moon of an asteroid. NASA Earth — on ice shelves and under glaciers overlaying extended the mission three times to take advantage of Galileo’s volcanoes — they developed a four-step model to explain unique science capabilities, and it was put on a collision course how the features form (Click for diagram of the model). The into Jupiter’s atmosphere in September 2003 to eliminate any chance of impacting Europa. model resolves several conflicting observations. Some The Galileo mission was managed by NASA’s Jet seemed to suggest the ice shell is thick. Others suggest it Propulsion Laboratory in Pasadena, Calif., for the agency’s is thin. Science Mission Directorate.
-13- Stellar Extremophiles Nov. 7, 2011: Back in collapse and contract under the 1970s, biologists were the pull of their own gravity. amazed to discover a form If a cloud gets dense and of life they never expected. hot enough as it collapses, Tiny microorganisms with nuclear fusion will kick in ancient DNA were living in and—voila!—a star is born. the hot springs of Yellow- The spiral arms of stone National Park. the Milky Way are a Instead of dissolving in the “goldilocks zone” for this boiling waters, the microbes process. “Here in the Milky were thriving, ringing the Way we have plenty of gas. springs with vibrant color. It’s a cozy place for stars to Scientists coined form,” says Neil. the term extremophile, This composite (radio+UV) image shows long octopus-like arms of star But when GALEX which means “extreme- formation stretching far away from the main disk of spiral galaxy M83. looks at other more distant loving,” to describe the [Click photo above for ScienceCast video on this story.] [Click here for spiral galaxies, it sees stars creatures—and the hunt more info on this photo] forming far outside the gassy was on for more. Soon, extremophiles were found living in form,” says Neil. deep Antarctic ice, the cores of nuclear reactors, and other But when GALEX looks at other more distant spiral unexpected places. Biology hasn’t been the same since. galaxies, it sees stars forming far outside the gassy spiral disk. Could astronomy be on the verge of a similar “I was dumbfounded,” he says. “These stars are truly transformation? ‘living on the edge.“ Researchers using a NASA space telescope named Spirals aren’t the only galaxies with stellar extremo- GALEX have discovered a new kind of extremophile: ex- philes. The observatory has also found stars being born treme-loving stars. —in elliptical and irregular galaxies thought to be gas-poor “We’re finding stars in extreme galactic environ- (e.g., example 1, example 2) ments where star formation isn’t supposed to happen,” —in the gaseous debris of colliding galaxies (example 1, explains GALEX project scientist Susan Neff of the Goddard example 2) Space Flight Center. “This is a very surprising development.” —in vast “comet-like” tails that trail behind some fast- GALEX, which stands for “Galaxy Evolution Ex- moving galaxies (example 1, example 2) plorer,” is an ultraviolet space telescope with a special —in cold primordial gas clouds, which are small and barely ability: It is super-sensitive to the kind of UV rays emitted by massive enough to hang together the youngest stars. This means the observatory can detect So much for the Goldilocks Zone. According to stars being born at very great distances from Earth, more GALEX, stellar extremophiles populate just about every nook than halfway across the Universe. The observatory was and cranny of the cosmos where a wisp of gas can get launched in 2003 on a mission to study how galaxies change together to make a new sun. and evolve as new stars coalesce inside them. “This could be telling us something profound about GALEX accomplished that mission—and more. the star-forming process,” says Neff. “There could be ways to “In some GALEX images, we see stars forming make stars in extreme environments that we haven’t even outside of galaxies in places where we thought the gas thought of yet.” density would be too low for star birth to occur,” says GALEX Will extremophiles transform astronomy as they did team member Don Neil of Caltech. biology? It’s too soon to say, insist the researchers. But Stars are born when interstellar clouds of gas GALEX has definitely given them something to think about. Author & Production Editor: Dr. Tony Phillips | Credit: Science@NASA For More Information: View the “Website of the Month” featured on page 7 in this month’s FOCUS.
“Understanding the Heavens” at UofD Academy of Lifelong Learning Carolyn A. Stankiewicz At the Osher Institute at the Academy of Lifelong Learning at the asked several DAS members to be guest lecturers in the class. I was University of Delaware, I taught a course on Basic Astronomy titled thrilled when several DAS members stepped up! Lynn King came in “Understanding the Heavens.” This venue is a learning cooperative in costume as Caroline Herschel, Harry Shipman explained various which courses relating to music, art, history, politics, sciences and over 200 astronomical principles, Hank Bouchelle was the point man when it came to other courses are offered for those 50 years of age and older who are making and explaining planetspheres, Rob Lancaster gave the class an intellectually curious. All instructors are volunteers and love doing it! This informative and fun planetarium show here at Mt. Cuba and Greg Lee was past semester, there were around 35 Osher Institute members enrolled in instrumental in sharing with the class his observational skills. Some my class. I have taught Basic Astronomy for several semesters, including members have chosen to attend public nights at Mt. Cuba and have our summer session. attended our monthly meetings. Outreach is very important to any Along with the students viewing videos featuring Dr. Alex organization and the above members have shown interest in our commu- Filippenko (The Teaching Company) and listening to special topics, I had nity. Thank you! -14- A Star with Spiral Arms Oct. 31, 2011: For more planet may produce a spiral than four hundred years, arm on each side of a disk. astronomers have used The structures around SAO telescopes to study the great 206462, however, do not form variety of stars in our galaxy. a matched pair, suggesting Millions of distant suns have the presence of two unseen been catalogued. There are worlds, one for each arm. dwarf stars, giant stars, dead Grady’s research is stars, exploding stars, binary part of a five-year interna- stars; by now, you might tional study of newborn stars suppose that every kind of and planets using the giant star in the Milky Way had 8.2 meter Subaru Telescope. been seen. Operated by the National That’s why a recent Astronomical Observatory of discovery is so surprising. Japan, Subaru scans the Researchers using the heavens from a perch almost Subaru telescope in Hawaii 14,000 feet above sea level at have found a star with spiral the summit of the Hawaiian arms. Two spiral arms emerge from the gas-rich disk around SAO 206462, a volcano Mauna Kea. From The name of the star young star in the constellation Lupus. This image, acquired by the there it has a crystal-clear is SAO 206462. It’s a young Subaru Telescope and its HiCIAO instrument, is the first to show view of innumerable young spiral arms in a circumstellar disk. The disk itself is some 14 billion star more than four hundred miles across, or about twice the size of Pluto’s orbit in our own solar stars and their planet-forming light years from Earth in the system. (Credit: NAOJ/Subaru) [Click pic above for larger image.] disks throughout the constellation Lupus, the wolf. Milky Way. SAO 206462 attracted attention because it has a circumstel- “What we’re finding is that once these systems lar disk—that is, a broad disk of dust and gas surrounding reach ages of a few million years—that’s young for a star— the star. Researchers strongly suspected that new planets their disks begin to show all kinds of interesting shapes,” might be coalescing inside the disk, which is about twice as says John Wisniewski, a collaborator at the University of wide as the orbit of Pluto. Washington in Seattle. “We’ve seen rings, divots, gaps—and When they took a closer look at SAO 206462 they now spiral features. Many of these structures could be found not planets, but arms. Astronomers have seen spiral caused by planets moving within the disks.” arms before: they’re commonly found in pinwheel galaxies However, it is not an open and shut case. The where hundreds of millions of stars spiral together around a research team cautions that processes unrelated to planets common core. Finding a clear case of spiral arms around an might give rise to these structures. Until more evidence is individual star, however, is unprecedented1. collected—or until the planets themselves are detected— The arms might be a sign that planets are forming they can’t be certain. within the disk.“Detailed computer simulations have shown Whatever the cause of the arms, their reality is us that the gravitational pull of a planet inside a circumstellar undeniable and the great catalogue of stars has one more disk can perturb gas and dust, creating spiral arms,” says type. Stay tuned to science@nasa for future entries. Carol Grady, an astronomer with Eureka Scientific, Inc., who is based at NASA’s Goddard Space Flight Center. “Now, for Footnote: (1) “There have been other examples of circumstellar disks the first time, we’re seeing these dynamical features.” imaged with partial spiral arms or blurry spiral arms,” notes Marc Kuchner of Goddard, who organized the conference. “So it’s not th Grady revealed the image to colleagues on Oct. 19 completely unprecedented. But this is really the first clear image of this at a meeting at Goddard entitled Signposts of Planets. phenomenon—clear enough that you could trace the arms and possibly Theoretical models show that a single embedded use them to make quantitative inferences about what’s causing them.” Author & Editor: Dr. Tony Phillips | Credit: Science@NASA
-15- Cassini Chronicles the Life and Times of Saturn’s Giant Storm Nov. 17, 2011: New images and animated movies from NASA's Cassini spacecraft chronicle the birth and evolution of the colossal storm that ravaged the northern face of Saturn for nearly a year. These new full-color mosaics and animations show the storm from its emer- gence as a tiny spot in a single image almost one year ago, on Dec. 5, 2010, through its subsequent growth into a storm so large it completely encircled the planet by late This false-color mosaic from NASA’s Cassini spacecraft shows the tail of Saturn’s huge January 2011. northern storm. Image credit: NASA/JPL-Caltech/ The monster tempest, which extended north-south approximately 9,000 miles Space Science Institute (15,000 kilometers), is the largest seen on Saturn in the past two decades and is the › Click above for Full image and caption largest by far ever observed on the planet from an interplanetary spacecraft. On the › Click for Additional view same day that Cassini's high-resolution cameras captured the first images of the storm, Cassini's radio and plasma wave instrument detected the storm's electrical activity, revealing it to be a convective thunderstorm. The storm's active convecting phase ended in late June, but the turbulent clouds it created linger in the atmosphere today. The storm's 200-day active period also makes it the longest-lasting planet- encircling storm ever seen on Saturn. The previous record holder was an outburst sighted in 1903, which lingered for 150 days. The large disturbance imaged 21 years ago by NASA's Hubble Space Telescope and comparable in size to the current storm lasted for only 55 days. The collected images and movies from Cassini's imaging team can be seen at This series of images from NASA’s Cassini http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov and http://ciclops.org. They include spacecraft shows the development of the largest mosaics of dozens of images stitched together and presented in true and false colors. storm seen on the planet since 1990. Image "The Saturn storm is more like a volcano than a terrestrial weather system," credit: NASA/JPL-Caltech/Space Science Institute said Andrew Ingersoll, a Cassini imaging team member at the California Institute of › Click above for Full image and caption Technology in Pasadena. "The pressure builds up for many years before the storm erupts. The mystery is that there's no rock to resist the pressure – to delay the eruption for so many years." Cassini has taken hundreds of images of this storm as part of the imaging team's "Saturn Storm Watch" campaign. During this effort, Cassini takes quick looks at the storm in between other scheduled observations of either Saturn or its rings and moons. The new images, together with other high-quality images collected by Cassini since 2004, allow scientists to trace back the subtle changes on the planet that preceded the storm's formation and have revealed insights into the storm's develop- ment, its wind speeds and the altitudes at which its changes occur. The storm first appeared at approximately 35 degrees north latitude on Saturn These two false-color views from NASA’s Cassini spacecraft show detailed patterns that and eventually wrapped itself around the entire planet to cover approximately 2 billion change during one Saturn day within the huge square miles (5 billion square kilometers). The biggest disturbance Cassini had storm in the planet’s northern hemisphere. Image previously witnessed on Saturn occurred in a latitude band in the southern hemisphere credit: NASA/JPL-Caltech/Space Science Institute called "Storm Alley" because of the prevalence of thunderstorms in this region. That › Click above for Full image and caption › Kaleidoscopic rainbows animation storm lasted several months, from 2009 into 2010. That disturbance was actually a › False-color animation cluster of thunderstorms, each of which lasted up to five days or so and affected only the local weather. The recent northern disturbance is a single thunderstorm that raged continuously for more than 200 days and impacted almost one-fifth of the entire northern hemisphere. "This new storm is a completely different kind of beast compared to anything we saw on Saturn previously with Cassini," said Kunio Sayanagi, a Cassini imaging team associate and planetary scientist at the University of California, Los Angeles. "The fact that such outbursts are episodic and keep happening on Saturn every 20 to 30 years or so is telling us something about deep inside the planet, but we have yet to figure out what it is." Current plans to continue the mission through 2017 will provide opportunities The largest storm to ravage Saturn in decades for Cassini to witness further changes in the planet's atmosphere as the seasons started as a small spot seen in this image from progress to northern summer. NASA’s Cassini spacecraft on Dec. 5, 2010. Image "It is the capability of being in orbit and able to turn a scrutinizing eye wher- credit: NASA/JPL-Caltech/Space Science Institute › Click above for Full image and caption ever it is needed that has allowed us to monitor this extraordinary phenomenon," said Carolyn Porco, Cassini imaging team leader at the Space (continued on next page) -16- NASA’s Hubble Finds Stellar Life and Death in a Globular Cluster Nov. 22, 2011: A new NASA Hubble Space Telescope image shows globular cluster NGC 1846, a spherical collection of hundreds of thousands of stars in the outer halo of the Large Magellanic Cloud, a neighboring dwarf galaxy of the Milky Way that can be seen from the southern hemisphere. Aging bright stars in the cluster glow in intense shades of red and blue. The majority of middle-aged stars, several billions of years old, are whitish in color. A myriad of far distant background galaxies of varying shapes and structure are scattered around the image. The most intriguing object, however, doesn’t seem to belong in the cluster. It is a faint green bubble near the bottom center of the image. This so-called ‘planetary nebula’ is the aftermath of the death of a star. The burned-out central star can be seen inside the bubble. It is uncertain Th whether the planetary nebula is a member of NGC 1846, or simply lies along the line of sight to the cluster. Measurements of the motion of the cluster stars and the planetary nebula’s central star suggest it might be a cluster member. This Hubble image was taken with the Advanced Camera for Surveys in January of 2006. The cluster was observed in filters that isolate blue, A new NASA Hubble Space Telescope image shows globular cluster NGC 1846, a spherical collec-tion of hundreds of thousands of stars in the outer halo of the Large Magellanic Cloud, a green, and infrared starlight. As a neighboring dwarf galaxy of the Milky Way that can be seen from the southern hemisphere. Image member of the Large Magellanic Credit: NASA and the Hubble Heritage Team, STScI/AURA; Acknowledgment: P. Goudfrooij, STScI Cloud, NGC 1846 is located roughly › Click above for Larger image | Click here for globular cluster alone
160,000 light-years away in the direction of the constellation Saturn’s Giant Storm (continued from previous page) Doradus. The Hubble Space Telescope is a project of Science Institute in Boulder, Colo. "Seven years of taking international cooperation between NASA and the European advantage of such opportunities have already made Cassini Space Agency. NASA’s Goddard Space Flight Center one of the most scientifically productive planetary missions manages the telescope. The Space Telescope Science ever flown." Institute (STScI) conducts Hubble science operations. The Cassini-Huygens mission is a cooperative STScI is operated for NASA by the Association of Universi- project of NASA, the European Space Agency and the ties for Research in Astronomy, Inc., in Washington, D.C. Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena manages the mission for the agency's Science Mission Directorate in Washington. The Cassini orbiter and NASA Develops its two onboard cameras were designed, developed and New Game- assembled at JPL. The imaging operations team is based at the Space Science Institute in Boulder, Colo. JPL is a Changing division of Caltech. Technologies For more information about the Cassini-Huygens Click the Picture mission, visit http://www.nasa.gov/cassini and http:// at left and find out all saturn.jpl.nasa.gov. about them! Author: Jia-Rui Cook | Credit: Jet Propulsion Laboratory, Pasadena, Calif. -17- DAS CONTACTS Please call any of us with your concerns! Board members: Education: Bob Karcha -- 302-999-9509 Officers Observing: Greg Lee -- 762-5358 or President: Bill Hanagan -- 302-239-0949 or [email protected], also, What’s Up? [email protected], also, ATM and Observatory: Tom Sidowski -- 302-239-1884 or Astronomical Photography Special [email protected] Interest Group, By-Laws, programs & Library Glenn Bentley -- 610-869-0706 Star Parties Board Members at Large Vice-President: John Case -- 302-838-1568 or [email protected] David Swartout -- 836-4618 or [email protected] Secretary: Lynn King -- 302-764-8816 or also, Awards Committee Chair [email protected], also, Messier Club Terry Lisansky Treasurer: William McKibben -- [email protected] Bob Mentzer [email protected] Sky & Telescope & Astronomy Other Chairs: magazine issues Rene Van Caneghem -- 410-392-3718 , Archivist Standing Chairs Sheila Vincent --302-322-4739, Ad-hoc star parties Publications: Joe Neuberger -- 410-398-7394 or [email protected] also, FOCUS contri- MCAO Web Page: www.MountCuba.org butions / submissions DAS Web Page: www.DelAstro.org FOR NEW MEMBERSHIPS or RENEWALS If you have questions, call any of the member representatives listed. Otherwise, just check the appropriate boxes and complete the form below. Print it or cut it off and send it with your check to Bill McKibben at his address on the form. The magazine prices are group rates to DAS members. If you’re just joining us for the first time, THANKS, and welcome to the DAS! ------MEMBERSHIP or RENEWAL FORM Please make checks payable to DAS and forward to: Bill McKibben, DAS Treasurer, 27 Mary Jane Lane, Elkton, MD 21921
New Member Senior/Family Membership $30.00 Renewal Junior membership (16/under) $10.00 Astronomy Magazine $34.00 Sky & Telescope Magazine $33.00 (*First Year Only) NAME______
STREET ADDRESS______Total Submitted $
CITY______STATE______ZIP______TELEPHONE______
E-MAIL ADDRESS______*See the “Magazine Subscriptions” section in the FOCUS for information about Sky & Telescope subscription renewal
The Last Word. . . I wish to apologize to Willis Greiner for mispelling his name in last month’s special Astro-Photo issue. Sorry, Willis! And he sent along this great note which illustrates the lifelong influence our organization can have: “Joe, The issue looks great. Also, the issue gives me a chance to “meet” the AIG group and others that I’ve never met, via the photos. I did know Luther Porter and Emil and a lot of the other original mem- bers (Jim Kauer checked me out on the 12 1/2 inch telescope), although I was a child when I joined. FOCUS editor My very supportive Dad drove me out to the Sawin Observatory and waited patiently while I attempted Joe Neuberger to find objects, etc., even though he was really just an interested bystander, not a true amateur astrono- mer. That was before the domed observatory was even built, and before any of those large suburban And to all a houses were there. We would walk up on the hill “behind” the Sawin structure and look out at one (!) farm and adjacent buildings that were there. But, think of it; those experiences led me to a lifetime of enjoyment, with travel, as you can see by perusing the photos.” ~Willis