University Lowbrow Astronomers

Dob-servin’.

by Christopher Sarnecki
Printed in Reflections: August, 2002.

A night of excess

Friday night, July 5th, I met several invited observers out at Clayton Kessler’s future home and dark site north of Manchester [all locations in this article are Michigan locations].  The night was exceptionally clear and the site was extraordinarily dark.  So dark in fact, that Clay’s site rivals the Lake Hudson Recreational Area, west of Adrian, favored by many Lowbrows.  A small faint A-squared nebula, in the east, was the only minor light pollution to be seen.  Low horizons were available all around, especially the prized summer southern sky.  The best part of all was the commute.  Driving to Lake Hudson usually takes me almost 1-1/2 hours, but the road trip to Clayton’s was less than half that.  Next time you see Clayton ask him about his building plans.  An observatory is rumored.

I have been reading a book that can be recommended to anyone whom considers himself or herself a dedicated observer.  Deep-Sky Wonders, by Walter Scott Houston has become my book of choice to find those new observing challenges that keep me looking forward to the next night of new adventures under the stars.  The book is a reprint of many of Houston’s best “Deep-Sky Wonders” columns originally appearing in Sky & Telescope magazine from 1946 to 1994.  Deep-Sky Wonders is dedicated to observational amateur astronomy.  Arranged in a monthly fashion, the reader only has to read up on the current month’s chapter to find out ‘what’s-up’.

Now on to the dob-servin’.  Every one knows summertime is globular cluster time.  Scotty’s book turned me on to number of new NGC globulars.  Before I knew it, I managed to bag some 30 mostly non-Messier globulars before the night was over.  Some of the interesting ones you may wish to check out are:

Fear of Planetaries

Planetary nebulas are the term astronomers first gave to these swollen greenish-bluish stellar disks because they looked the planet Uranus.  I have never enjoyed planetary nebulas much beyond the Messier’s four bright planetaries M27, M57, M76, and M97.  It seems that most of these objects are smallish and too faint to be differentiated from field stars.  Recently, a number of Lowbrows have turned me on to a number of NGC planetaries that are not difficult to locate and observe.  Also, I have learned that, yes, higher magnification is required; but more important, is what to look for.  High magnification helps turn these stellar looking objects in to resolvable disks.  Many of the brighter NGC planetaries are noticeably greenish or bluish color.  Others, like NGC 2392, the Eskimo planetary in Gemini, (a winter object) have an observable central white dwarf star.  This central star is easy, try it.  Some even have discernable shapes beyond the usual circular disk.  The Ghost of Jupiter, NGC 3242 in Hydra (a late winter, early spring object) has a pair of ears viewable in the scope.

A technique for helping one to locate the planetary from its stellar neighbors is to hold an Oxygen III filter up to the high power eyepiece.  The nebular will respond well to filter while many of the fainter stars will drop out of the picture.  My experience is the OIII filter overpowers some the fainter features of the nebula.  So I typically will not screw the filter into the eyepiece, but hold it over the eyepiece.  Once I view the nebula in question I put the filer down and enjoy the view without it.  If I can warm up to planetaries, than any one can.  Some summertime NGC planetaries are listed here.  Check ’em out.

Perhaps some of you read the article in Sky & Telescope’s Observer’s Log last year (September 2001) on locating the central star in the Ring Nebula.  Well, I always wanted to attempt observing this object.  The article tells us that picking out the central star one needs a 8 inch scope minimum, high magnification, a night of steady seeing, and the faint magnitude star chart reproduced showing stars fainter that the Ring’s 15th mag central star.  Together with Clayton and Jeff WHN, ccd imager extraordinare from the DAS, we set out to see this star.  Using the chart, we located a star at an incredible 15.7 mag opposite a 13 mag star bracketing the center of the ring.  Waiting for moments of steady seeing we manage to pick out the central star flashing momentarily in and out of our view.  I am convinced that other Lowbrows can pick out this star if you follow the steps we took.  Remember to look for the central star when the Ring is at zenith to eliminate looking through too much atmosphere.

Observing Challenge

NGC 6822, Bernard’s Galaxy, 19 h 45 m RA, -14 degrees 48’ Dec is an 11 mag dwarf galaxy +/- 10 degrees east northeast of the teaspoon asterism in Sagittarius.  This galaxy is large, 10’ x 20’ in size, with low surface brightness.  Robert Burnham, Jr. of Burnham’s Celestial Handbook indicates that it is visible in 6” - 10” scopes (presumably from the Lowell Observatory) and easier than the Veil.  This object’s location is easily to find since three 5th mag stars point the way.  You may want to save this one for your summertime dark site.  I’d be interested in hearing from anyone spotting this object.

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Copyright © 2013, the University Lowbrow Astronomers. (The University Lowbrow Astronomers are an amateur astronomy club based in Ann Arbor, Michigan).
This page originally appeared in Reflections of the University Lowbrow Astronomers (the club newsletter).
This page revised Sunday, March 9, 2014 4:30 PM.
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