Nova NotesThe Newsletter of the Halifax Centreof the Royal Astronomical Society of CanadaVolume 36 | Number 5 | October 2005PO Box 31011, Halifax, Nova Scotia, Canada B3K 5T9 www.halifax.rasc.ca email@example.comAstrophoto of the Month — Beginners Astronomy WorkshopOn November 5th Tony McGrath held a beginners workshop at St. Mary’s to help out beginner members, photo courtesy of Gary Weber.Observing and ImageChallenge: Find andRecord the Lunar XDave ChapmanIn August 2004, at Nova East, severalobservers saw an interesting illuminatedX-shaped feature on the nearly first quarterMoon, on the dark side of the terminatornear Crater Werner. The X was brilliant,and completely surrounded by darkness.Tony Jones took a picture of the X andDave Chapman wrote a letter to SkyNewsto go with the picture. The X is nowknown to repeat strictly periodically every29.53 days, but it is a fleeting effect andonly lasts a few hours, so one has to bein the right place (longitude) to see theX at the right time. The X has beenobserved since on several occasions byobservers in various locations, but wasnext seen in the Halifax area only onNovember 8, 2005. The next localappearance is predicted to be January 6/72006, with the prime time between 7 p.m.and 8 p.m. AST. I would be interested incollecting any new observations of theLunar X, including high-quality astrophotosor drawings. I am planning to write anarticle for publication in JRASC or elsewhere,and I am looking for a high-quality imageto illustrate the article. Dave Chapman,firstname.lastname@example.org.
Las Cumbres AmateurOutreach AwardMary Lou Whitehorne has been selectedto receive the 2005 Las CumbresAmateur Outreach Award, which honorsoutstanding educational outreach by amateurastronomers to K-12 children and theinterested lay public. Whitehorne has a longhistory of public outreach and education.She volunteered for years at the formerHalifax Planetarium, organizing, promoting,and producing regular weekly programsfor the public and school audiences. Shetrained more than 200 teachers to usethe StarLab planetarium—used to teach8000 to 10000 school children eachyear—and continues to participate inteacher workshops. She made regularappearances on the CanadianBroadcasting Corporation’s morningshow as the “science and spaceperson.” She has volunteered formany organizations, such as theRoyal Astronomical Society of Canada,the Nova Scotia Museum of NaturalHistory, the Nova Scotia Museum ofIndustry, Girl Guides of Canada,Discovery Center, and others.Whitehorne has also served on theAdvisory Board for the CanadianAstronomical Society Educationand Outreach Initiative. But perhapsher most remarkable contribution isthe book SkyWays, an astronomyhandbook for teachers that waspublished last year by the RoyalAstronomical Society of Canada.Astronomy programs in schools acrossCanada will benefit from this wonderfulaccomplishment and from Whitehorne’scontinuing work in and enthusiasm foreducation and public outreach. ✯Observing Passionby Paul HeathThe sand was still warm as my father andI climbed up the back of the dune. Wesettled a short way down the dune facingout towards the lake. Laying back on ourblanket the Milky Way stretched out overheadand stars filled the sky. My dadpointed out the Big Dipper then said tolook up and watch. Shortly a meteorswept across the sky. “WOW”. ‘There aremore, just lie back and watch’, my fathertold me. As we settled back I began tofeel a breeze up off the lake. I could smellthe beach debris and hear the waveswashing onto the beach. As we waitedand watched more meteors shot acrossthe sky. As the shower intensified, themeteors began to shoot out over the lake.A loon called in the marsh behind thedunes and curlews piped from down thebeach. Then the sky lit up as a doublemeteor shot down the sky diving deepinto the lake. We watched for two or threehours until the breeze grew to a chillingwind. Climbing back up the dune I fellmany times, trying to walk up that sandyhill and watch the sky at the same time.What is it that keeps one observing thenight sky?A passion begins, often with a pivotalevent that affects ones psyche, a momentof awe and amazement that drives one toexplore further into the wonder that wehave seen. And yet this event may notovercome the many changes in one’s life.Often it is a series of ‘awe events’ thathelps to continue that passion to explore.Events that capture again that mix ofsight, sound, smell, and touch that firstamazed and filled our minds with wonder.We continue to observe, with search programsor new toys, but perhaps our realhope is for that moment of awe and wonderwhich will refresh our first moment ofamazement, the moment that our passionbegan. To become again that seven-yearoldlying on warm sand, watching thestars fall into a summer lake.No matter what your ‘awe’ moment was,may it keep you under the stars until youdiscover that next moment of wonder.Maybe you will be able to help spark thatmoment in someone else and pass thatpassion along. ✯Nova NotesThe Newsletter of theHalifax Centre of the RASCPO Box 31011Halifax, Nova ScotiaB3K 5T9Articles on any aspect of Astronomy willbe considered for publication.Nova Notes is published bi-monthly inFebruary, April, June, August, October andDecember. The opinions expressed hereinare not necessarily those of the HalifaxCentre.“Letters to the Editor” or letters to ourresident expert “Gazer” are also mostwelcome.Contact the editor at the following:Michael Gattoagatto@ns.sympatico.ca453-5486 (Home) 482-1013 (Work)Nova Notes is also available as aPDF file on our Centre’s website atwww.halifax.rasc.caMaterial for the next issue should reach the editor by Dec 20/05
Simple Radio MeteorObservingMike BoshatUghhhh … 5:30 a.m., I drag myself outof bed and log on to do some asteroidsearching on the SpaceWatch web page.Waiting for the images is very tiresome soI set up my dipole antenna on the balconyand get the Icom R-10 receiver ready fora few hours of meteor listening. Boy, whata difference than using the old black andwhite TV method!So, how does one go about “listening” formeteors? Well, there are 2 ways: the TV orradio method, the latter is better on the eyes.We have all seen meteors, but what happensto allow us to hear them? As meteorsburn up in the atmosphere they ionize theair around them, and this area acts like a“mirror” with the ability to reflect radiosignals. So if you have an antenna set up,when a “below the horizion” meteor goesby, a transmitted signal will be reflectedto you. Pretty straight foward.Now how to detect the signal. The TVmethod requires that one use a black &white TV with NO cable attached. Anantenna can be a wire strung across theroom or you can make a simple dipoletype. Now the main thing with either TVor radio is that you HAVE to use a channelnot in use and a radio station that eitheryou know exists but cannot hear or scanslowly, more later on that. Back to theTV method. You turn the TV on and go tochannel 2 which is at 55.25 MHz. Youwill see “snow” (not the stuff we get inthe winter) then turn the volume down oryou’ll go nuts listening to the “Shhhhhhh”for a few hours. Also reduce the brightnessof the screen or you’ll begin to seereally weird patterns! Now set the antenna,and if a dipole is used turn it roughlytowards to the southwest as mostTV/radio stations are along the easternseaboard. Now watch for either a brightwhite line or black line lasting from 1/4 to1 second. This is a meteor. During meteorshowers you’ll see quite a few. Just countthe number you see each hour. The TVmethod is a “starter” method, an inexpensiveway but does have a few drawbacks.Notably it is hard on the eyes and when thereis Sporadic E in the upper atmosphere itwill reflect TV/radio signals and you’ll seethis enhanced on the TV thus makingmeteor looking poor. Sporadic E usuallyoccurs in the summer months.Now we come to the radio method. Herewe have 2 ways, one is with an ordinaryFM radio (a digital one is preferred) andthe other a HAM (amateur radio) receiver.Again a dipole antenna will suffice. A briefnote on FM radio, it is said that someobservers can hear meteors from the middleof a city with a car FM radio … well,I would really doubt that as I’m using aspecial filter to eliminate as much backgroundstations and noise as possible. Ihave yet to hear a meteor on an FM radiofrom Halifax. So, I would take most ofthis with a grain of salt.OK, you get a digital FM radio and havean antenna. The basics of this method isthat you tune in to either a known distantstation frequency were you can either“just” hear the station or cannot hear it.When a meteor goes by it will enhancethe station signal for a brief second or so.Or alternately, you do not know any distantstation frequency and here will need toscan from 87 MHz up the dial, stoppingand listening for enhanced signals. This isa little tougher to do, once you get past88.00 MHz you start to run into local stationsthat saturate the radio. Have a list ofknown local FM stations to skip by. Onceyou do detect a signal mark the frequencydown and you’ll not be trying to rememberit when a meteor shower occurs.The HAM radio method use amateurreceivers which are generally more expensive,but with better features and they area tad more sensitive to meteor detection.Way back in 1998 bought an Icom R-10receiver as it is small and portable. Ihooked my antenna to it and turned it onbut got an emense amount of strong staticand saturation from other stations. I wastrying to figure out how to eliminate it. Ihad some help from the American MeteorSociety, they sent small filters for me tohook up between the radio and antenna,but they did not work as hoped. Afterquite awhile of this annoyance I contactedSaint Mary’s University and we worked onthe problem. I received a loan of a larger“cavity” filter which was placed betweenthe radio and antenna to reduce as muchunwanted interference as possible. I setthe radio to the unused Channel 6 stationat 83.25 MHz and pointed my antenna tothe south west and began to hear meteorsgalore. I detected more meteors using theCW (Contionus Mode) that the AM modeon the radio. I could also use the USB(Upper Side Band) and LSB bands (LowerSide Band) to hear meteors.So I began to monitor meteors each day,usually in the morning from 6 a.m. tilnoon depending upon what shower wasactive. Of course there are sporadic meteorsand showers that produce small to highrates that can occur. One interestingobservation was the Leonid meteor showerin 1998 and 2002, I could go to anotherfrequency not tuned by the filter and stillhear them continously.A brief note on frequency and meteors,the higher up you go in frequency the lessmeteors you will hear, so lower frequenciesfrom about 50 MHz to 90 MHz would bebest to monitor. Also, awhile back RadioShack put out a scanner called Pro-60which was able to monitor the TV channelsI monitor, and I did hear meteors withthat scanner.What do I do with the data each month?I send it off various astronomy groups andthey use data from around the world todetermine how the meteor showers arebehaving.Below are listed meteor radio sites thatone can get more information and planson radio meteor work, meteor showers,and a few notes, references, and periodicalswith radio meteor information.Radio Meteor Sites1) American Meteor Society - RadioMeteor Projectwww.amsmeteors.org/radmet.html2) Dutch Meteor Societywww.dmsweb.org/3) International Meteor Organizationwww.imo.net/4) Meteor Scatter Sitewww.meteorscatter.net/5) Radio Meteor Observing Bulletin— send your data to themvisualrmob.free.fr/index.php6) Listen to Meteors on the webwww.roswellastronomyclub.com/radio_meteors.htm7) Meteor Shower, Aurora andSporadic-E Detectionwww.tvcomm.co.uk/radio/3
Some NotesWhat is meteor scatter (MS) ?Meteor scatter is a form of electromagneticwave propagation. The ionized trail ofmeteors (typically appearing between 100km and 80 km high) acts temporarily asa reflector for radio waves. A meteor doesNOT generate detectable radio emissionitself!In the case of forward scatter, the transmitterand receiver are at different locations.Backscatter can be seen as a special case,whereby the sender and receiver coincide(typically the case of radar).Meteor scatter can be used day and night,allowing daylight meteors streams to bestudied. Meteor scatter can also be usedfor secure communication.Is it always possible to observe ?Unfortunately, other forms of propagationinterfere with MS. The worst one issporadic-E or Es, consisting of conductionclouds in the high atmosphere that makepermanent reception of remote stationspossible for either minutes or tens of minutes.The sporadic-E season is from May to Julyin large parts of the northern hemisphere.In some regions however, sporadic-E isunknown!There are also tropospheric influences.A temperature inversion can also causereception over wider ranges than normal.Thunderstorms cause verysharp peaks. On FM,most of these (amplitudemodulated)spikes aresuppressed. However,DO NOT connect yourantenna to your receiverduring thunderstorms orwhen you are absent forlonger time. Lightningstrikes have ruined severalradio shack receivers.Happy Listening! ✯ReferencesThe reference is still “MeteorScience and Engineering” byD.W.R. McKinley, McGrawHill1961. A fantastic book, giving the theory and practicalresults of the heydays of the radio meteor science.A very concise, but technical, introduction to thesubject is: Schanker, Jacob Z., “Meteor BurstCommunications”, Artech House, Norwood, MA, 1990ISBN 0-89006-444-XAnother classical work is “Meteor Astronomy”, Lovell,A.C.B., University Press, Oxford, New York, 1954."GeneralBlack, W.H., Observing Meteors by Radio. Sky &Telescope, July 1983, pp.61-62.Pillon, K., Meteor astronomy at home (ComputerAdventures). Popular Science, May 1984, pp. 80.Black, W.H., A visual/radio meteor observing interface.WGN 17-4, 1989.Lynch, J.L., A Different Way to Observe the Perseids.Sky & Telescope, August 1992, pp. 222-225.Mason, J., Tuning in to meteor showers. AstronomyNow, February 1994.A Beginner’s Readingby John VandermeulenI very much regret having missed the2005 Nova East gathering. As a newmember, I had wanted to meet others,and put faces to names, plus the advantageof seeing different telescopes, andhear the talks and workshops by JohnDobson. From all accounts, this was notthe one to miss. Instead, I spent 12 daysand nights in the Dartmouth Hospital,dressed in one of those flimsy ‘nighties’that tie at the back. I did have a very largewindow, 4th floor, but it overlooked a brilliantlylighted parking lot so that evenbinoculars were useless. So—plenty ofreading time.For that I was prepared. Last winter I spenta fair amount of time reading exchanges4on the Internet, in particular the CloudyNights website, and that of Astromart forrecommended books to read or buy. I alsoqueried individual amateurs and a numberof RASC members as to their choices.Putting together all responses and recommendationson books I eventually drew upa list of reading that scanned the field,both astronomical and cosmological. Notsurprisingly, high up on the list were thetrio of Nightwatch, The BackyardAstronomer’s Guide and Turn Left atOrion. More surprisingly—as the folks Icontacted were primarily amateurastronomers—several respondents namedThe Whole Shebang by Timothy Ferris,Brian Greene’s twin books The ElegantUniverse and The Fabric of the Cosmos,the First Three Minutes by StephenWeinberg, anything by Michio Kaku, andStephen Hawking’s A Brief History ofTime - all cosmological treatments.Support in the background are two textbooks - Astronomy: The Cosmic Journey,and Astronomy: The Structure of theUniverse - loaned by Clint Shannon.I decided to go the cosmos-route, withBrian Greene’s The Elegant Universe, asit is easy to hold up while lying in bed,whereas Turn Left at Orion and other’sreally are “coffee-table” sized. The ElegantUniverse is a thick paperback (445pp), withlots of hype from reviewers and readers,especially as Greene himself has considerablereputation as a founder of string theory.The first half of the book is wide-rangingand easily read, a clearly written introductionto those familiar topics, relativity andquantum mechanics. Things can get a bitthick in the second half of the book, asthere he focusses on string theory. Several
newspaper reviews, and those promotionalprinted claims on the back cover, allpraise Greene’s style, and how he simplifiesstring theory. Which obviously means thatthe folks writing that praise are all a wholelot wiser than I am. Greene’s writing probablyis the clearest there is on the subject,but it can still go over one’s head. (Wouldyou believe that Stephen Hawking’s A BriefHistory of Time is far lighter in contentand tone?)Any library on Astronomy/Cosmology thatI have looked through is split more or lessaccording to those terms. The astronomysection concerns locations, descriptionsand discoveries of stars, planets, galaxies,black holes,and how it is all put together—the hunting grounds for the telescopeobservers. The cosmology section holdsthe more theoretically inclined literature,the playing ground for them that like math,high energy physics, and speculation aboutthe early universe. If this is your choice, itis probably a good idea not to fear quantummechanics, relativity of both kinds, andthe latest how-to theory on the block;string theory.Don’t get me wrong—those astronomicalcerebral activities such as detectingmoons from the orbit of others, supernovae,star-lensing, dark halos in galaxies,and “apsidal waves in the Kuiper Belt” isnot for sissies. And astronomical-leaningpapers can be equally chuck-full of equationsand maths. Take your pick. One thingI have learned is that astronomy is notsome single focus, telescope orientedactivity. I found sections, and sub-sections,and sub-sub-sections - and then beginover again when trying to encompasscosmology (cosmogony?).Anyway, for me the basic library beginswith what must be the ultimate threebibles of amateur astronomy—BackyardAstronomy’s Guide, Nightwatch, and TurnLeft at Orion—at least in north America.Every website on amateur astronomy, orbooks, or introduction to telescopesmentions at least one, if not all three asessential to one’s library. They are all largesize, and gorgeously produced, but not cheap.All are aimed at the beginner, and frommy own perspective, successfully. Any oneof these would be an excellent Christmasor birthday gift. And although they shareeither material, content or an author, theydo not overlap.The Backyard Astronomy’s Guide has givenme a very good overview; very thorough.It is a dandy beginners book. But go slowly,as there is a lot, a whole lot of materialand information in it. The next one,Nightwatch, is just what it is subtitled, “APractical Guide to Viewing the Universe”with emphasis on our solar system andMilky Way galaxy. This book almost dovetailswith the Backyard Astronomy’s Guide.Not too surprising as Terence Dickenson isco-author of the latter, and main author ofNightwatch. Nightwatch is a useful fieldguide,with the very handy coil-bound spineso that it can lie flat, instead of layingrocks on it to keep it from curling closedon itself. I personally liked his very clean,uncluttered chapters. The book is very“telescope oriented”.Number three in the trio, “Turn Left AtOrion”, is my favourite, both for its catchytitle, and its surprisingly detailed contentof the so-named Messier bodies. Althougha coffee-table size, this is nonetheless a‘working book’, and really belongs in one’sfield case, in a plastic bag so that it won’tget dirty. No chit-chat, just charts. Oneshould also have some prior knowledge ofthe layout of the constellations, as that ishow most of these tiny objects are denoted.It is a fine guide map to the Messierobjects, those visible “smudges” that aresometimes a challenge to find, view, andrecord. A particularly nice feature is thateach ‘local map’ of a cluster or deep skygalaxy is marked with symbols for observing—practicalstuff such as refractorscope size, necessary sky conditions, sizeof eyepiece, when best seen, possiblewith binoculars, and with reflector ondobsonian mount.While on the subject of information-ladenbooks, my first acquisitions were two“must-haves”—the “Observer’s Handbook2005" and “The Beginner’s ObservingGuide”—both published by the RoyalAstronomical Society of Canada, and bestof all they’re cheap. I don’t know whatamateurs in other countries have forbooks of this ilk, but these two (paperbacks)are hard to beat for all manner ofastronomical information, both necessary,esoteric, and even the picayune. Do note:these two paperbacks are information-factladen, not for casual reading.This brings me back to my small scopeout on my sundeck. By now being morecomfortable with it (I bought it last fall),I went for the constellations—Orion withhis three-star belt (very obvious) is myparticular favourite, possibly because itwas the first constellation I identified. Butif it is not available then there are the twodippers, each part of larger constellations,that between them occupy a large part ofthe firmament. Although I haven’t quitelost my frustration, or helplessness overthe myriad of stars, just simply toonumerous to even think about.Where I met the near impossible waswhen surfing through the sheer infinitenumber of stars “further back” in the sky.This feeling actually began, for myself,when opening the box that my little scopewas mailed in. Astronomy, telescope, andall those other descriptive words conjureup something invisible, very far off, themagic of life. To a total beginner, the telescopeis a very strange apparatus, withvery specialized pieces of highly prizedglass parts, and seems imposing. Iremember very well my own awe, when Iopened the box holding my small 4.5"scope and looked at bits and parts thatuntil then I had only seen in stores andbooks. And then, when you throw into themix the discovery that the little white spoton the black background is a real body thatmay be 100,000 or even 100,000,000kilometers away, the word delirium comesto mind.Then came my first view, tentatively of themoon, several times over several evenings.The next step, one evening, came when Ilet the scope sort of drift over star fields,stars so numerous that they seemed thickerthan the grass on my lawn. At first Ijust scanned around a bit, and then wantedto go further, but this sheer number of starsdefeated me, as I am sure have manyothers, as just what to do with all thesespots on the black background. Actually,Guy Consolmagno, co-author of TurnLeft… from Easton Pennsylvania (and aJesuit at the Vatican Observatory) askedhimself the same question. To quote:“eventually it occurred to me that all thebooks in the world weren’t as good ashaving a friend next to you to point out toyou what to look for … it’s not that peoplearen’t interested, but on any givennight there may be 2,000 stars visible tothe naked eye, and 1,900 of them arepretty boring to look at in a small telescope.”I must underline here the bit about thefriend sitting next to you, a mentor whocan brush away the strangeness of yournew telescope. The operative word hereis “friend”, someone who can guide you5
Part of your membership in the Halifax RASC includes access toour observatory, located in the community of St. Croix, NS. Thesite has grown over the last few years to include a roll-off roofobservatory with electrical outlets, a warm-room and washroomfacilities. Enjoy dark pristine skies far away from city lights, andthe company of like minded observers searching out those faintfuzzies in the night.Members’ NightEvery weekend closest to the new Moon there is a Members’ Night at St. Croix. The purpose of members’ night is to attractmembers from the Centre to share an evening of observing with other members. It’s also a great night for beginners to try outdifferent scopes and see the sky under dark conditions. For more information or transportation arrangements, please contact theObserving Chairman Daryl Dewolfe at 902-542-2357. Dates for Members’ Nights for the following few months are:Dec, no “official” night due to holidaysFriday, Jan. 04 (alt. Sat., Nov. 05th)Directions from Halifax(from Bayers Road Shopping Centre)1. Take Hwy 102 (the Bi-Hi) to Exit 4 (Sackville).2. Take Hwy 101 to Exit 4 (St. Croix).3. At the end of the off ramp, turn left.4. Drive about 1.5 km until you cross the St. CroixRiver Bridge. You’ll see a power dam on your left.5. Drive about 0.2 km past the bridge and takethe first left (Salmon Hole Dam Road).6. Drive about 1 km until the pavement ends.7. Drive another 1 km on the dirt road to the site.8. You will recognize the site by the 3 small whitebuildings on the left.Become a St. Croix Key HolderFor a modest key fee, members in good standing for more than ayear who have been briefed on observatory can gain access to theSt.Croix facility. For more information on becoming a key holder,contact the Observing Chairman Daryl Dewolfe at 542-2357.RULES FOR THE 17.5" SCOPE(OR ANY RASC SCOPE AT SCO)On Members’ Nights the 17.5" scope must be shared by allmembers. The 17.5" scope can be used by anyone, but all viewshave to be shared with anyone interested in taking a look.On non Members’ Nights the scope can be used by individualswishing to work on personal observing projects. Membersshould try to limit their use to under 45 minutes when othermembers are waiting to use it. Preference will be given tomembers who send an email to the hfxrasc list, or call theobserving chair on the night they want to go out. If no oneelse wants to use the scope then feel free to use it all night,but it would be considerate every so often to ask membersthere if anyone has been quietly waiting to use it.Please contact the Observing Chairman Daryl Dewolfe formore information or to book the scope at 902-542-2357.7