Sharing tips and techniques to help amateur astronomers get the most out of light polluted skies.

Urban Messier Challenge

The Messier catalog lists some of the finest objects in the northern skies. Observing all of the Messier objects is one of the classic rites of passage for amateur astronomers. There are also a variety of challenges related to the Messier Catalog, the most famous of these being the Messier Marathon: a race to see all of the Messier objects in a single night. There are also binocular Messier challenges and photographic Messier challenges. My own addition to this is an Urban Messier Challenge: a list of Messier objects that are particularly challenging for urban and suburban observers dealing with skies washed-out by light pollution. In dark skies you can see all of the Messier objects with a 3 inch (75mm) aperture, but with heavily light-polluted skies you’ll have a hard time seeing the Messier objects on my urban challenge list even with significantly larger apertures. Here is the challenge list...


Enjoying Jupiter

Jupiter photo by NASA/JPL/University of ArizonaJupiter offers great observing opportunities for urban astronomers. It is very bright, easy to find and shows interesting details even in small scopes. A view of Jupiter through a telescope will never fail to impress your family, friends, and neighbors. It’s relatively large size, cloud detail, and the ballet of its moons make Jupiter my favorite planet to observe. But after you’ve stared at Jupiter for the 20th time, then what? Well, here are few ideas of things to look for that should keep you busy for many nights to come...

Photo courtesy of Jupiter photo by NASA/JPL/University of Arizona.


Star-hopping Tutorial: Lesson Two (M27)

 M27For the second lesson in the star-hopping tutorial series, we’ll star-hop from Albireo (β Cyg) to M27, the Dumbell Nebula. This is a relatively short star-hop—in fact it is shorter than M57, our first lesson. But unlike M57 where we star-hopped using 3rd and 4th magnitude stars, this star-hop will rely on fainter 5th and 6th magnitude stars—stars that are usually invisible in washed-out skies...

Other tutorials in the series:  Lesson 1Lesson 3


Zhumell 10 inch Dobsonian Reflector

Zhumell 10 inch DobsonianSince 2007 my primary telescope has been the Z-10: a Zhumell 10 inch (250 mm) Newtonian reflector on a Dobsonian mount. Many might argue that so much aperture is wasted in washed-out skies, but I found the Z-10 suits my needs quite well. It is sometimes claimed that in light-polluted skies larger apertures only further brighten the background and diminish contrast; that in washed-out skies you can actually see more with smaller apertures. I’ve found that to be simply another urban legend: the Z-10 does quite well in pulling in DSOs from my front yard despite the heavy light-pollution. It consistently shows objects that I can’t see with smaller apertures. The Z-10 also just fits in my car (a VW Passat), allowing me to easily take it to nearby parks or to far-away dark-sites.

I’m reasonably satisfied with the Z-10, although it isn’t a perfect telescope by any means. The optics are okay (but not great) and the mount is reasonably steady. As with all Dobs, I’ve made some modifications to make it better suited to my needs....


Star-hopping Tutorial: Lesson One (M57)

Illustration of a chart of Lyra such as would be used for star hoppingStar-hopping is one of the most valuable skills in amateur astronomy. In the days before computerized mounts and GPS, star-hopping was the only way to find interesting objects. Thanks to the steady march of technology, not as many amateurs today are proficient star-hoppers. In fact, quite a few amateurs have never star-hopped. Still, for many of us without computerized mounts, star-hopping remains a critical skill. Washed-out skies in particular can really test your star-hopping skills: when only 3rd or 4th magnitude stars are visible, it can be a pretty long hop from the nearest visible star to your target. Even if you have a computerized mount, star-hopping can be useful in light-polluted skies: with many faint fuzzies at the ragged edge of visibility, star-hopping techniques can confirm that you are indeed looking in the right place.

To help you master star-hopping I am planning a series of tutorials, starting with the simplest of star-hops and continuing with successively more challenging star-hops. Each one will end in an interesting object suitable for viewing with a modest telescope under washed-out skies. We start with a very simple star-hop from Vega to M57, the Ring Nebula...

Other tutorials in the series:  Lesson 2, Lesson 3


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