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equipment review This new 6-inch telescope offers high-quality Schmidt-Cassegrain optics in a portable package. ⁄ ⁄ ⁄ BY phil harrington Celestron’s new Schmidt-Cassegrain Celestron has introduced a new model to its Schmidt-Cassegrain line of telescopes — the C6, and it’s Celestron’s most portable one yet. This scope offers a 6inch aperture and operates at f/10. Family resemblance is unmistakable. The C6 has a sleek black aluminum tube with the company’s name and logo emblazoned in orange across its side. Consumers may choose from four variants. For those who already own a telescope mount, the C6 is available as an opticaltube-assembly only. The least expensive complete C6 package, designated the C6-S, combines the telescope with Celestron’s Advanced Series CG-5 German equato- rial mount. The same C6 also is sold with the computerized version of the CG-5 as the C6-SGT. Finally, Celestron added the C6 to its lineup of single-support-arm NexStar Special Edition instruments. The NexStar 6SE, however, features an orange tube rather than black. All varieties of the C6 come with a 25mm E-Lux Plössl eyepiece (60x) and a 11⁄4" prism star diagonal. A THE C6 is Celestron’s newest Schmidt-Cassegrain telescope. Its tube measures 16 inches long and weighs 9 pounds. Both the orange dovetail mounting bar and 6x30 finder scope are included. ALL PHOTOS: ASTRONOMY: WILLIAM ZUBACK; star chart: astronomy: richard talcott and roen kelly 76 astronomy ⁄⁄⁄ © 2009 Kalmbach Publishing Co. This material may not be reproduced in any form www.Astronomy.com march 07 from the publisher. without permission ⁄⁄⁄ s p e c i f i ca t i o n s Celestron C6 Type: Schmidt-Cassegrain telescope Aperture: 6 inches (150mm) Focal ratio: f/10 Focal length: 1,500mm Length: 16 inches (406mm) Weight: 9 pounds (4.1 kg) Included: StarBright XLT coatings, 6x30 finder scope, 11⁄4" prism star diagonal, CG-5 dovetail mounting bar Price: $588 Contact information: Celestron, LLC 2835 Columbia Street Torrance, CA 90503 [t] 310.328.9560 [w] www.Celestron.com 6x30 finder scope is also included with each, except for the NexStar 6SE, which has a one-power red-dot finder instead. Celestron coats all C6 primary and secondary mirrors with enhanced coatings for better reflectivity and less scattered light. Peak reflectance is 95 percent at a wavelength of 510 nanometers, with an average reflectance of 93 percent across the visible spectrum. The corrector plate is ground from water-white float glass and then layered with the company’s proprietary StarBright XLT anti-reflection optical coatings for improved light throughput. These coatings Phil Harrington loves telescopes of all types. The 4th edition of his telescope-review book, Star Ware, is now on sale. U BO E s ade Plei GA TAU R U S N MO US R CELESTRON coats all optical surfaces with its StarBright XLT hightransmission, anti-reflection coatings for improved light throughput. C NO AN US Be tel ge us e ER ID 42 M OS l A ER S DR IS N R CA INO M ge HY N n yo Proc Ri TA Hyades Aldebaran M1 IO OR O RV T Po l LE 5 M6 04 M1 CO A lu x GEMINI Castor M35 M37 M36 M38 NX LEO M INOR AU RI LY TI M66 la ebo Den GO R X CANCER s IES P lla pe a C U M RS A JO R A NA M64 VIR SE C M44 RN lu AR l go Al S S ER EU M82 CA NE S V E CI ES NGP C O M A BER ENI C us IP TI C OF TH E S UN ECL T M81 Mi za r M5 1 A RI NG ÖT ES Arct ur Re gu PATH SA TU ius S U EP L S NI R The C6’s tailpiece 11/4" accessories. A rubber-coated focus C A accepts JO 1 MA M47 Sir knob adjusts the telescope’s M4 primary mirror. PYXIS reflect less than 0.5 percent of the light Focus by turning a small rubber-coated saw ara the Great Red Spot and even the Adh A N striking them. Just as I found in a previous T Lknob that protrudes from the scope’sI Sback. shadow of one of Jupiter’s moons transiting IA PUPP test of Celestron’s C8-SGT with the same Focus moves the primary mirror fore and across the planet’s face. coatings (Astronomy, August 2004), image aft along a track inside the tube. All teleAfter enjoying A Jupiter for a while, I MB 477 LU brightness was excellent in the C6. scopes that focus images in this manner moved on to several beautiful globular clusO NGC 2 C Apart from being smaller (an advantage suffer some degree of image shift caused by ters: M13 in Hercules, M22 in Sagittarius, V E L A tilting slightly when focused. if portability is high on your wish list), the the mirror and M2 in Aquarius. All three showed good C6 looks like the C8. A gold-anodized This makes the image “jump.” Through the detail through the 25mm eyepiece. dovetail bar bridges the 16-inch-long tube. C6, however, image shift was negligible, Next, I resolved some challenging douThe bar attaches the scope to the mount. perhaps 10" (arcseconds) at most. ble stars, including the Epsilon (ε) Lyrae quartet, Delta (δ) Cygni, and Alpha (α) Under the stars Piscium, at magnifications up to 300x with I selected Jupiter as my first target. Images a 5mm eyepiece in place. Jupiter also held through the C6 proved impressive. Jupiter’s its own at that magnification, although, atmosphere showed great detail. I clearly because of sky conditions, the view was better through a 10mm eyepiece (150x). Star-testing showed the optics to be smooth and well-figured; they produced nearly perfect images on either side of focus. Celestron didn’t leave imagers behind, either. The C6 accepts the same wide array of accessories used by other SchmidtCassegrain telescopes, which makes the C6 perfect for astrophotography. Overall, Celestron’s C6 struck me as the perfect telescope for anyone who needs a highly portable instrument yet still wants a large enough aperture to see the sky well. For a great little telescope at a great little CELESTRON includes a 11/4" star diagonal and a 25mm price, look no further. Celestron E-Lux Plössl eyepiece (60x) with the C6. www.astronomy.com 77 Keep your eyes on the sky and renew your ASTRONOMY subscription Don’t break your link to the leading astronomy magazine on the market. Renew your subscription and continue to receive the insightful astronomical information that fills every issue: ✰ New-product listings ✰ Expert observing tips ✰ Field tests: telescopes, cameras, binoculars, eyepieces, accessories ✰ Monthly pullout star maps ✰ And exclusive online access to Star Atlas, Star Dome Plus, The Sky this Month, Ask Astro archives, videos, image galleries, product information, and more! RENEW TODAY! www.Astronomy.com/ASYRENEW Plus, why not share your enthusiasm? It’s easy to send someone a gift subscription today! Give a gift today at www.Astronomy.com/ASYGIFT CIR-ADH-09X1241RH