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This is not a star hopping tutorial. I want to cover far more basic territory by discussing the observing session itself. This page is to help make your first few times out a little more enjoyable by helping you think through what you will be doing. I hope it doesn’t scare you away from observing.
Deciding Upon An Observing Site
The first thing that needs to be settled is where will you set up to observe? I no longer observe from my backyard because I find it far too frustrating. My neighbor to the east has an insecurity light in his yard. This actually increases his odds of being a robbery victim (ask any law enforcement person if you don’t believe me). To the west of me, my neighbor has a driveway that looks like an airport runway. So my yard is extremely well lit. This keeps my eyesight from becoming fully dark-adapted.
If I have just described your yard but you still intend to observe in it, you might want to block some of that light. If it is a porch light, you might simply be able to explain what you are doing and the neighbor will be willing to temporarily turn off the light, especially if you invite them over to look through your scope. Otherwise try positioning your scope where you can’t see the lights directly. Use a building or hedge for this purpose if possible. Another option is to put a screen between you and the light. A tarp or black plastic sheet will work. Some observers build panels that can be taken down and moved as necessary. One method would be to construct a PVC frame using plumbing supplies and duct tape and cover it with a plastic sheet.
Light pollution has become a major problem. If you live in the city you may only be able to see the moon, probably 5 planets, and maybe a few bright stars with your unaided eyes. This is going to make astronomy very difficult and limited for you. If you live in a smaller town you may be able to see quite a few more stars than in the city but the background sky will still have a glow to it that makes faint fuzzies hard to find and the amount of detail you see will be less than ideal. In my country setting I can easily see the Milky Way from horizon to horizon but there are still a couple of annoying sky domes in the direction of the nearby towns. The faintest stars I can visibly see naked eye are around magnitude 5 and sometimes closer to 6. This is considered pretty good by the standards of many today because of lights that stay on all night. I have never been to a truly dark sight but they tell me there are so many stars visible it can be difficult for those unfamiliar with such skies to get their bearings. Sadly too many people today have never even seen the Milky Way much less magnitude 6 or dimmer stars.
Light blocking panels would only solve part of my problems, as the bigger issue is trees. There isn’t much that can be done about trees except move the scope as far away as possible or cut the trees down. I only have a very narrow clearing directly overheard in my yard. I have a chain saw but that isn’t something that I really want to see happen. So for me the answer is to pack up my equipment and go elsewhere. I have a friend who lets me observe in a field behind his house. It is a big open area with no annoying lights and only one tree to the south. It is about as good as it gets around here. I caution you to use common sense and always know who owns the land and seek permission before you use it for observing.
Have A Viewing Plan
Before you set up your scope in your predetermined site, you need to figure out what you want to observe. Especially as a beginner, don’t wait until you get out under the stars to decide where to point the scope. Things will almost never go as planned but you should still have one. While just freely scanning the sky can be fun, it can also be very frustrating, especially if you don’t know where to look or what to look for.
Use a planisphere or star charting program to determine what constellations are visible during the time you want to observe. Then I recommend you use Night Watch or Sky Watch to pick out at least a few easy targets. If you subscribe to an astronomy magazine they will likely have some good objects listed in their current issue. Just make sure they are not challenge objects as there is little chance a beginner will find them.
When putting together your viewing plans, pay attention to the weather reports. That may seem too obvious to mention but while it may be sunny all day the cloud cover may be expected to roll in after dark. Likewise, the day’s clouds may break up early allowing for some scope time.
Check your local clear sky chart conditions for the cloud cover, transparency, seeing, and darkness expectations for the night. It is not always correct but more often than not is a good indicator of conditions. The darkness reading on sky clock relates not only to when the sun sets and rises but how the Moon will affect observing as well. You should be aware of when the Moon rises and sets and what phase it is in currently.
Lunar observing is actually best done when the Moon not full. This might seem counter-intuitive but the full Moon is so bright it actually renders its own surface less than ideal for viewing detail. Try to pick a night with a partial moon then view along the terminator – the line between light and shadow for some amazing views. Planets can take a lot more moonlight than galaxies and nebula. If you know were to look, you can see some planets while the sun is still shining. Though for maximum detail planets are best viewed when the Moon is new. Definitely, the closer to a moonless night it is, the better for observing deep space objects.
Make A List
Ok, you have figured out where and what you will observe. Now what? I would give serious thought to having a checklist of items you will need during your session. Even if you are setting up in your backyard this will help prevent running back and forth several times to get some item you hadn’t thought about. If you are driving to your observing site this becomes far more important. Who wants to drive back home because they forgot the eyepieces? Believe me such things happen.
Besides the obvious things – scope, mount, eyepieces, binoculars, what else should you have with you? Make sure you have a red light and your star maps. Do not use a white light except possibly when packing to leave and even then only if there are no other observers still set up. Most observers like to keep a log of their observing sessions or make sketches of what they see. For this you will need pencil and paper. I take a fold up table where I can sit my eyepiece case, maps, and note pad. I also take a fold up chair. Then I have a toolbox with wrenches and screwdrivers in case something needs adjusted. I include in the toolbox my collimation tools. I would suggest having extra batteries.
You should have a jacket or coat with you depending on your weather. You might want to pack a blanket. Then you should consider the extras like a cooler with drinks, some snacks, and maybe some music to observe by. Just don’t disturb the sleeping neighbors or other observers with your music. Make sure someone knows where you are and have a cell phone with you in case of emergencies, especially if you are driving to your observing site. I recommend never observing alone away from home.
One item I didn’t mention is bug repellant. Some people spray their site down upon arrival and then use Off or some other spray with Deet. Some people swear Skin So Soft will repel mosquitoes. What I have found that I think works is Thermacell. It is a little butane-powered device with a chemical wick that protects about a 10’ circle from the nasty biters. What ever you use don’t use Citrucel or any other burning bug rings. The chemical residue could possible get on your optics. That would not be a good thing. I have not read any reports on Thermacell causing problems.
Arriving At Your Observing Site
You should arrive at your observing site well before dark. This will give you plenty of time to set up your base of operation. Before even getting out of the car, if you have such an adjustment, turn off your dome light or any other lights that come on when the doors are opened. Later in the night this might just save your night vision if you have to get in your car for something.
Look over the site to clear it of rocks and branches that could prove hazardous in the dark. Likewise be aware of holes or other obstacles for the same reason. If you are in a parking lot be aware of curbs and bumper blocks that can be tripping dangers later.
Look over all your equipment to make sure all is in working order.
Spending the extra time now to make sure your mount is level and stable will payoff later in increased ease and enjoyment during your observing time. Depending on your scope and mount type you may need to balance your scope. If you have a reflector type scope taking the lens cap off the end of the tube will help the scope ‘cool down’ quicker. Proper cool down of the mirror will give better views.
If your scope requires occasional collimation (aligning the mirrors), you should check it and make adjustments now. I personally seldom find it necessary to collimate. Others will insist it needs to be done every time they set up. Maybe I am just extra careful in handling my scope or not very picky but it seems to hold its alignment very well. You have hopefully set your scope up in your living room and already taught yourself how to adjust the mirrors. I am not going to go through the steps here but will say after you have done it a couple times it is not nearly as confusing as the instructions make it out to be. Fear is the biggest drawback to overcome in learning collimation.
While it is still daylight make sure your finder is aligned with your eyepiece view. Put a low power eyepiece in the scope point it at a distant object (we often use telephone poles). Now adjust the finder screws so the finder view is centered on the same view as through the scope. You will be sorry if you neglect this step before it gets dark.
Get the main eyepieces you will be using that night organized for use. Put the lens caps, and finder caps in a safe location so they will be handy when packing up later. You’re almost ready for the dark, now get a drink, set back, and get out your maps to go over the plans you made earlier for this evenings session.
What To Do When It Gets Dark
Ok, its dark, you are all set up, and have a plan that you have reviewed. You are avoiding bright lights. Even your red light should be very dim. Your eyes are quickly becoming dark-adapted. You point your scope at the first target, look through the eyepiece and nothing is there – why not? First look in the finder. Do you see the target area in the finder but not in the scope? If yes then you have not aligned the finder to the scope. It is going to be tough to do in the dark. You should have listened to my earlier advice!
Maybe you have the target area in the field of view of the finder and the scope but still don’t see the object. Go back and check your charts and make sure you really are in the correct location. Star charts are hard to follow because they are printed backwards – left to right. In a reflector turning the map upside down should match the image in the scope's eyepiece. A reflector reverses the image left to right as well as upside down.
Use a lower power eyepiece so the amount of sky visible is wider. Maybe the target is just off to the side of where you're looking. You should usually start with your lowest power eyepiece for this reason. The bigger the number on the eyepiece the lower the magnification. Something in the range of a 25 to 32mm ep is usually appropriate.
If your ep view is correct to the map then try lightly jiggling the scope – be careful not to bump it out of position. This can make dim objects jump out sometimes. Also try looking off to the side of where the object should be located. This is called averted vision. Our eyes are less sensitive looking directly at an object. Looking off to the side can help bring it out. Try increasing the magnification. The object could just be very tiny. The Ring Nebula M57, for instance, is very small.
If none of these suggestions worked and you are properly on target then the object may be beyond your scopes ability to pull it in. It is also possible you just aren’t experienced enough to recognize what you are looking at. Objects through your scope will not look like the pictures in the magazines. There will usually be no color and DSO’s will often appear to be no more than very dim fuzzy patches, hence the term – faint fuzzies. Another possibility is the atmospheric conditions just are not conducive to good observing this night. Move on and try something brighter and easier. Don’t give up, just save this challenge for another evening.
When you do successfully observe an object you might want to make a sketch of it or write down notes about what you have observed. It is generally recommended that along with a detailed description of what you saw that you include the date, your location, the equipment you observed with, the magnification you used, and the Seeing and Transparency.
Seeing and Transparency are terms used by astronomers to describe the atmospheric conditions of the night skies during a viewing session. Beginners find these terms confusing and near impossible to understand the difference between them. Even seasoned observers are often guilty of using the wrong term. I still get confused and have probably misused seeing and transparency somewhere on this website.
Following is my attempt to define these terms:
Seeing refers to the steadiness of the atmosphere.
Transparency is determined by the faintest stars you can see with the naked eye.
The amount of atmospheric turbulence determines Seeing conditions. Under bad Seeing the stars will twinkle when observed naked eye and magnified objects will appear to boil. Good Seeing then is noted as little or no twinkling of the stars and steady images through the eyepiece. Transparency is controlled by the amount of moisture, smoke, pollution, and dust in the air. Poor Transparency causes the light from dim objects to be scattered making them dimmer thus harder to see.
Well that concludes my observing session basics article. It sounds like a lot of work and in some respects that is true. The however is if you approach your session with a plan and knowing what to be prepared for, you stand a much better chance of having a rewarding successful experience.
A final thought, as your night’s observing draws to an end, you will be tired and tempted to just throw stuff in the car and go. Not a good idea. Besides the fact that something might be damaged, there is the possibility of losing equipment. Take your time. Pack everything properly. Carefully go over your site after you load the car to be certain nothing has been left behind. Pick up any drink cans or wrappers you sat down during the night. As my dad always told us while camping, leave your site better than you found it.
I hope you found this helpful. If you did or if you have other suggestions just let me know.
Clear skies!
Copyright © 2009 by Kevin Sluder
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