100 Hours of Astronomy PAUL MOSS (WWW.ASTRONOMY.NET.NZ) AWorldwideAstronomy MARATHON Grab your scopes and friends and head outside! Early April will be amateur astronomy’s time to shine for the International Year of Astronomy 2009. If you have a telescope, mark April 2–5 on your calen- star party will sweep around the world, with local gather- dar. The world is coming your way. ings beginning as darkness descends. Even city street cor- An unprecedented string of public skywatching events ners will come alive, with the third annual International will be packed into this brief period, all designed to engage Sidewalk Astronomy Night happening the fi rst weekend people and bring them out for a worldwide star party that in April. Thus many sidewalk astronomy regulars will will cap the program on Saturday evening, April 4th. already be at their stations. Collectively, the period is called “100 Hours of Astron- omy.” It’s a Cornerstone Project of the International Year Get Involved of Astronomy 2009 (January issue, page 82) tailor-made This will be the largest amateur astronomy outreach for amateurs who’d like to try some out- event ever held, and everyone with a telescope is needed. MIKE SIMMONS reach. During the fi nal 24 hours a global Whether you’re an expert or a newbie yourself, whether your scope gets used regularly or has been relegated to a garage or closet, someone new should get their chance to JOIN THE PARTY It will be a worldwide celebration April 2–5, as the Interna- tional Year of Astronomy marks 100 Hours of Astronomy with public viewing, live see the heavens up close with it. It’s an experience every- webcasts, and much more. The party atmosphere could exceed this 2008 observ- one should have. ing event in New Zealand, which was punctuated with neighboring fi reworks. Visit the website for 100 Hours of Astronomy at 72 April 2009 sky & telescope © 2009, New Track Media, LLC. All Rights Reserved.
The Galilean Experience 100hoursofastronomy.org and you’ll fi nd resources for The Franklin Institute’s novice and experienced sidewalk astronomers alike. It exhibition, Galileo, the Medici, off ers tips on where to set up, how to advertise your event, and the Age of Astronomy, will what questions to expect (and how to answer them), and run from April 4th through more. Stargazers have been registering their events on the September 7th. It marks the fi rst website. The resulting listings and maps point the public — and perhaps only — time one to local events, allow you to fi nd a nearby group to team of the two surviving telescopes up with if you wish, and expedite collaboration between (shown at right) that Galileo used groups. And be sure to sign up for our mailing list. has left Italy. The exhibit will also t The 100 Hours of Astronomy will kick off on Thurs- feature other artifacts of the Medici family, who supported d ilh day, April 2nd, at the Franklin Institute in Philadelphia Galileo in his many scientifi c pursuits during the Renaissance. with the opening of the exhibition Galileo, the Medici, and You’ll fi nd visiting information, as well as details of the FRANKLIN INSTITUTE the Age of Astronomy. The show features many Galileo exhibit and associated programs, at www.fi .edu. artifacts, including one of the instruments that started it all 400 years ago: an actual telescope that Galileo built and used to take humanity’s fi rst steps beyond naked-eye time, that actually changes over short timescales. It’ll be stargazing (see the box at right). astronomy in motion. This VIP event will be webcast to the world and will Yuri’s Night, an annual celebration of the anniversary of set the tone for the rest of the program. Over the ensuing Yuri Gagarin’s fi rst human fl ight into space, is usually held four days we’ll make the 400-year journey from Galileo worldwide on April 12th. To avoid Easter this year it was to modern-day telescopes — and back to the thrill of moved up to April 4th, coinciding with 100 Hours. Many of Galileo’s discoveries at the eyepiece. these celebrations of humanity’s entry into space will wel- come amateur astronomers who off er to take participants Launch and Beyond on their own personal voyages of cosmic discovery. Online presentations will then continue, as experts from We encourage ama- various science centers line up to discuss hot topics in teurs not to wait their astronomy while visitors pose questions. At some facili- turn, though! Contact For links to the various projects and other ties, participants will have the opportunity to operate schools, museums, hos- resources for the International Year of Astronomy, telescopes remotely over the Internet. pitals, military bases, and visit SkyandTelescope.com/IYA2009. The professional astronomy community takes the other venues and off er to stage next. A live 24-hour webcast will follow darkness host star parties throughout the weekend. Find those who around the world, welcoming viewers inside the domes of can’t take advantage of this great opportunity and bring dozens of research observatories where astronomers will telescopes to them. explain their work. Scientists at control centers for space And don’t forget that half of those 100 hours are during telescopes will also join in. the daytime. The website has tips on solar viewing and Other outreach groups will take advantage of the high science from the Solar Physics Task Group of IYA2009. profi le of 100 Hours of Astronomy. The radio telescopes of Plans are still in the works as this issue goes to press. the European VLBI Network will conduct demonstrations Check the website for the full schedule — it’s the portal to and live observing by following a celestial object, in real everything happening worldwide. All of this leads up to the grand fi nale: the 24-hour global star party that sweeps around the world as the SHARE THE SKY Sun sets on April 4th. Everyone who watched the events Spread celestial unfold online will be encouraged to leave their comput- awareness by giving others the ers behind and see the fi rst-quarter Moon and Saturn up opportunity to close, as Galileo did for the fi rst time four centuries ago. observe through The 100 Hours of Astronomy has something for every- your telescope. one: new sidewalk astronomers, experienced outreach specialists, and anyone who’s every wondered what the Moon really looks like. This is an opportunity 400 years in the making. It’s not likely to be repeated soon. ✦ WALLY PACHOLKA / TWAN Mike Simmons is co-chair of the 100 Hours of Astronomy Cornerstone Project and president of Astronomers Without Borders (astronomerswithoutborders.org). SkyandTelescope.com April 2009 73 © 2009, New Track Media, LLC. All Rights Reserved.
Gary Seronik Telescope Workshop Testing, Testing, 1, 2, 3... Examining stars with your telescope mirror is the key to optical excellence. Without doubt, the fi nal arbiter of a telescope’s in which the mirror can be mounted. So is there a way optical quality is the star test. If no errors show up while to make the star test easier? Well-known science-fi ction carefully examining a star’s image at high magnifi ca- author and ATM Jerry Oltion has one solution — a dedi- tion inside and outside focus, then you have something cated star-test “telescope.” sensibly close to optical perfection. If you’re new to the Every Sunday several members of Oregon’s Eugene star-test concept, check out Harold Richard Suiter’s Star Astronomical Society meet at Jerry’s house to grind mir- Testing Astronomical Telescopes (published by Willmann- rors. “Our wives knit while we grind,” he jokes, “so we Bell) — it’s the defi nitive book on the subject. call the get-togethers our knitty-gritty sessions.” Rather Regardless of the indoor test methods you use while than build a bunch of individual scopes for star testing, fabricating your mirror, the star test is worth performing Jerry designed a rig to accommodate all the mirrors the as a crucial reality check. Indeed, relying on bench test- group is working on. Their projects range from 6-inch ing alone can lead to mistakes — just ask the folks who f/8 and 8-inch f/4 mirrors to a 16-inch f/6, so they needed made the primary mirror for the Hubble Space Telescope. to position the focuser and secondary mirror between 32 The star test is very sensitive, accurate, and relatively and 96 inches from the primary. easy to perform. It is, however, inconvenient. You need a Jerry’s bare-bones test telescope is made from lumber clear night with steady seeing conditions and a telescope and plywood, and it’s aimed at Polaris. The North Star is an ideal target for star testing — it’s about the right brightness and it’s essentially stationary in the sky. By using Polaris, he simplifi ed construction of the scope’s mount. The front end of the scope is simply propped up on a hinged length of 1 × 2 lumber. “The scope is surpris- ingly easy to nudge around,” Jerry notes. “For left-right motions I just reach up and give it a pull or a shove, and for up-down motions I pull back or push forward on the bottom of the prop, which is nearly vertical, allowing rela- tively coarse movements to fi ne-tune the scope’s aim.” The scope’s design allows for testing a wide range of mirrors. The primary is supported on a pair of wooden pegs and leans back against three felt pads, all of which can be positioned to accommodate various mirror sizes. Four forward-facing collimation screws tilt the mirror board relative to a board forming the rear of the scope. The secondary support is made from a shelf bracket attached to the focuser board, which is held in position with a C-clamp. Simple, but eff ective. While Jerry’s star-testing scope won’t win any prizes JERRY OLTION for looks, it works wonderfully for the task for which it was designed. Visit Jerry’s web site (www.sff .net/people/ j.oltion/) to learn more about his telescope making. ✦ Jerry Oltion’s bare-bones scope is a dedicated rig for star test- ing primary mirrors. Inset: To accommodate various mirrors, the focuser and secondary mirror can be repositioned easily on the Contributing editor Gary Seronik grinds and tests mirrors optical axis. The secondary is clamped to a shelf bracket, and the from his home in Victoria, British Columbia. You can con- focuser board is clamped to the scope’s main strut. tact him via his website, www.garyseronik.com. 74 April 2009 sky & telescope © 2009, New Track Media, LLC. All Rights Reserved. 009, New Track Media, LLC. All Rights Reserved. © 2
Sean Walker Gallery ▾ CELESTIAL SMILE ▶ THE KEYHOLE NEBULA David Jurasevich Ricardo Serpell The evening of November 30, and Daniel Verschatse 2008, brought a particularly To the right of the bright star memorable conjunction of Eta Carinae in this photo, NGC Venus, Jupiter, and the Moon as 3324 is a dark nebula composed seen here over hazy Los Angeles, of dust and gas in the process of California. forming embryonic stars. Details: Canon EOS 5D digital Details: 16-inch RCOS Ritchey- SLR camera with 24-70-mm zoom Chrétien telescope. Apogee U47 lens. Exposure was 2½ seconds at CCD camera. Total exposure was ISO 640 from the 60-inch refl ector 192 minutes through Astrodon dome, Mount Wilson Observatory. narrowband fi lters. 76 April 2009 sky & telescope © 2009, New Track Media, LLC. All Rights Reserved. 009, New Track Media, LLC. All Rights Reserved. © 2
▴ BERNARD’S GALAXY Tom Harrison Residing in Sagittarius, NGC 6822 is a member of our Local Group of galaxies. This unusual dwarf contains a large number of active star-forming regions, glowing reddish in this remarkable natural-color image. Details: 12½ -inch RCOS Ritchey-Chrétien telescope, SBIG STL-6303E CCD camera. Total exposure was 12½ hours through Astrodon color fi lters. ◀ FLAMING STAR NEBULA Scott Tucker and Dail Terry The brightest nebulae in Auriga, IC 410 (left) and IC 405, the Flaming Star Nebula (right), appear bisected by a bright grouping of colorful stars, and are faintly visible in binoculars from dark skies. Details: Celestron 11-inch Schmidt-Cassegrain telescope at f/2, Starlight Xpress SXVF-M25C CCD camera. Mosaic of two frames, each totaling 30 minutes. SkyandTelescope.com April 2009 77 © 2 © 2009, New Track Media, LLC. All Rights Reserved. 009, New Track Media, LLC. All Rights Reserved.
Gallery ▴ DOUBLE DELIGHT Roth Ritter A spectacular sight through any instrument, the famous Double Cluster in Perseus comprises the open star clusters NGC 884 (left) and NGC 869, thought to have formed from the same cloud of gas and dust only a few million years ago. Details: 10-inch RCOS Ritchey-Chrétien telescope, SBIG STL-11000M CCD camera. Total exposure was 190 minutes through color fi lters. ▶ AUTUMN CONJUNCTION, TAKE 2 Daryl Willmarth On the evening following David Jurasevich’s photo on page 76, Daryl Willmarth journeyed to Kitt Peak National Obser- vatory in Flagstaff , Arizona, to capture the memorable event. Details: Canon Digital Rebel EOS XTi digital SLR camera with 24-105-mm zoom lens. Exposure was 4 seconds. ✦ Gallery showcases the fi nest astronomical images submitted to us by our readers. Send your very best shots to [email protected]. We pay $50 for each published photo. See SkyandTelescope. com/aboutsky/guidelines. 78 April 2009 sky & telescope © 2009, New Track Media, LLC. All Rights Reserved. 009, New Track Media, LLC. All Rights Reserved. © 2
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