BECOMING A BETTER ASTRONOMICAL OBSERVER

During my first year as an observer, I learning through a lot of reading, many observing sessions (with a wide range of success and failure) and help and advice from astronomical friends. During this time I have improved my skills and I would like to share what I have learned.

1. HAVE A GOAL AND STICK WITH IT! While this is one of those obvious things, I overlooked this in my early months and had a lot of frustration from going into the back yard and saying "gee, I wonder what's up there tonight?" I quickly found swinging the scope around randomly unsatisfying. Clubs award certificates for having observed all Messier objects. This is a great goal because they are all in the reach of small telescopes, most star atlases include them, and a nice assortment of objects are available any night of the year to us North Americans. Other goals include watching prominent asteroids or comets traverse the sky over a period of weeks or months, seeing all of the planets and their major moons (you need a friend with a big scope for Pluto), and observing and drawing the major features of the moon. The other areas of astrophotography, solar observing, and satellite observing each have their own joys and tough accomplishments.

2. PLAN YOUR OBSERVING! After establishing my goal, this activity was the next most significant to improving my observing. Nothing is more frustrating than rifling through an out of order stack of star charts, trying to figure out which one is "up" and then studying the chart to see if anything interesting is available, all in the dark. It always seemed that the most interesting object just went below the trees.

The two key aspects in this planning are determining what you want to see and when and where you can see it. There are plenty of affordable materials to support this planning. The basic set for deep sky objects would be a small sky atlas (magnitude 6 or better) and a "planisphere" or star finder, one of those wheel things where you use time and date to move a big hole over a little star map to show what stars are visible at that time. I have moved a step up from this to a Bgiht Star Atlas, Sky Atlas 2000, Uranometria 2000, and IBM PC programs Skyglobe and Megastar which handily have all the Messier objects and can display and print from full sky to a narrow corner with a lot of stuff in it. For a long night, I will print out views of the four points of the compass at 10:00 PM and 1:00 AM, circle the objects I need and note the atlas chart numbers where I can locate them in their detailed context. For more current solar system events like comets, asteroids, and planetary activity, get a current copy of "Astronomy" or "Sky and Telescope" magazines; they are rich with opportunities, finder diagrams, and suggestions. They each also include a pretty good unaided eye "view of the sky this month" to substitute for the planisphere. These periodicals also have observing plans for parts of the sky which are convenient to the season.

Having established the goals for the evenings viewing, I write down the best sequential plan I can, considering elevation above the horizon, any skyglow, priorities, and time. It is also necessary to leave some slack time for clouds and resting because I find crouching over the telescope for 5 hours rather fatiguing.

3. OBSERVE WITH DISCIPLINE! It is very easy to get distracted from an observing plan. Several obstacles have been problems for me. (1) Being outdoors at night is either damp and bug infested or chilly; it is a real contrast to compare looking at a beautiful detailed color photograph of the eagle nebula on my sofa at home with struggling to find the eagle's faint and vague glow in my 4.5" reflector while fighting dew on the finderscope and swatting mosquitos. Prepare for these contingencies. I guess after a while you get used to it. (2) The first time you go somewhere for dark sky you may be overwhelmed by the richness of full, unpolluted night sky. I had trouble finding basic constellations my first such night because there are all those little dim stars obscuring the constellation outlines and so much viewing to choose from. (3) If there are other observers around you, like at a star party, don't go chasing everything you hear them observing unless you are comfortable trashing your plan. If it's something really interesting go peek through their instrument, particularly if it is bigger than yours. It takes me a long time to find some objects and if I am having trouble with one and the next scope over says "Wow, what a great planetary!" I get this mixture of frustration and envy and I want to go prove that I can find it too, and it's probably not near as hard to find or resolve as my object, etc. These negative feelings seem to pass but are frustrating and natural for the novice.

The finding of objects with a telescope is one of the fundamental skills of the amateur astronomer. If you go to a star party with good sky you will hear starhops and strategies discussed. I can regularly find what I am looking for but it takes a while. My method is to find a bright star in the vicinity of my object of interest on the star chart. I locate this star visually and then with the finder on my scope. Juggling the star chart so that my view of it matches the view in the finder, I hop from faint group of stars to faint group of stars (in the finder) until I get close to the object of interest. This is an exercise in star pattern recognition and visualization from the chart: "I want to go in the direction of the long side of that trapezoid until I find an arrow shape and the globular is 2/3 of the way between the arrow and a brighter pair of stars beyond it". It usually takes me a 2 or 3 tries to get it unless the object is visible in the viewfinder, a happy circumstance for many Messier objects. Once I locate the place where the object should be in the viewfinder, I bounce over to the eyepiece and sometimes it is actually there. Experienced observers make a quick glance at the chart (only if it is an unfamiliar target) and zoom in on it swiftly with a Telrad.

Once I have captured the object in the telescope, I make a few notes and a drawing. A small telescope won't resolve individual stars of a globular or show any detail in most galaxies so my drawings are very simple. They have proven to be a powerful tool for improving my skills and squeezing more fun out of a nights observing. I have adapted the format suggested by the "Observer's Guide" periodical and sketch as much detail as I can see. My notebook is a half page planner size binder (it sits nicely on the knees) and it holds the starfinder, indexes to the Sky Atlas, various handy lists and observing and plan pages.

4. EVALUATE THE RESULTS OF YOUR OBSERVING! When I get in from an observing session, I do several evaluations. I write a brief summary of the evening's work and compare results to plan and note any things I learned about how to do better next time. Among the realizations I have made during these "debriefs" are the importance to me of a good plan, the benefits of keeping good notes and drawings, and never even attempt galaxies from my light polluted back yard. I have also learned not to try to take too many magazines or books to an observing session; there is not time or light to use more than the main charts, plan, and notebook. Where I was unable to see objects like faint globulars or galaxies from my backyard, these go on a list to catch when I can get to darker skies. I compare my sketches and observation notes to reference material from Burnham's Celestial Handbook, photos in coffee table books, and anything else that describes the object. This activity is a final confirmation (or in a couple cases, a rejection) of a sighting and I find some strange joy in getting the angular size and shape correct within 10% and getting the pattern of stars in the vicinity almost as well as Palomar. Where there are discrepancies, I can usually relate them to limitations of aperture and this more than anything makes me want a larger scope. Where I have not found objects, I can usually attribute this to faintness or light pollution.

The evaluation of results against several references has added some method to my reading and has illustrated some of the discrepancies in interpretation of Messier's ancient (1786) list. One list rejects a total of 5 objects, two of which I have found (M47 and M48), while most lists reject only M40 and M91.

Periodically, I evaluate my progress toward my goal. I keept a PC spreadsheet of the whole Messier list and recorded dates of observation. I use the data sort option to build a shrinking list of objects not yet observed, sorted by constellation for more long range planning. I completely missed the Virgo galaxies one year and had to hit them hard the next. I also computed an extrapolated date of completion, computed from my average rate of object capture. The final evaluation is a plot of Messier count achieved by date. I am pleased to report an exponential shape of the curve which reflected my steadily improving observing skills.

SUMMARY: My overall observing process is mostly the result of slow improvements over a period of time. If I had conceived of it initially, it would have seemed "too organized" and "not enough fun". When I would get frustrated with a problem, I sought help and guidance and would try to do better. I am fortunate that I could pursue my goal at least partially from my back yard so I have progressed steadily. My few visits to dark sky have benefitted from the lessons slowly learned.


By Dennis J. Webb, originally from 1991, copyright 1997. Personal and nonprofit use permitted. Contact the author at denjwebb@aol.com for other use.

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