Taking Notes
By Shawn Grant
Why take notes? Note taking allows one to keep a record of what he or she has observed for future reference. By going back to your notes you will be able to know what you have seen and what the object looked like under certain conditions. You can go back to an object and see if there are any changes. Say you observed a galaxy and a year later you go back to it and see a star in the galaxy. You go back to your notes and you didn't note that you had seen that star. Though various other sources you can confirm a supernova. It allows one to share their observations with a friend or with Deep Sky Online or various other sources. One can also obtain great observing rewards from the AL such as, the Messier or the Herschel certificates. These certificates can not be obtained without taking notes of your observations. One can feel great pride when one of these certificates is obtained. Note taking notes also promotes one to observe the object more carefully. By carefully following some guidelines you will notice details that would other wise be missed.
How to take proper notes
Record the location and specify the altitude of the location. Give a date of the observation. State the beginning time of the observation and also the ending time. Specify the time used, universal time or local time. Provide information of the sky conditions such as seeing and transparency.
To determine transparency find out the magnitude of the faintest star visible near the zenith. This magnitude can be obtained by naked eye or through the telescope. With the naked eye get a chart that displays stars down to 7.5 or 8th magnitude. With the help of the chart identify the magnitude of the faintest star visible near the zenith. With a telescope it is a bit different. Find an open cluster with a high elevation and make sure the cluster doesn't have any bright stars in it (brighter stars can make it difficult to determine the limit). Use a computer program such as Guide, Megastar or TheSky, which can print charts of open clusters with the magnitudes of stars to find the magnitude limit. If you don't have a computer the book Visual Astronomy of the Deep Sky by Roger N. Clark has several charts of open clusters with the stars magnitude. Note whether the sky is hazy or partly cloudy, you know the general sky conditions.
Seeing is a different story, it is more difficult to determine. The way I determine seeing is by using a scale from one to ten, one being the worst and ten being the best. I make five average, typical for the location and time of year. I make an observation of seeing in the general area of the sky where the object is. The closer to the horizon the worst the seeing and the seeing will generally get better higher up in the sky it is. Make a note how high above the object is from the horizon also.
State the telescope size and its F/ratio you are using. Log what eyepiece you are using and its magnification. Are you using any filters? Be sure to state that because it can make a difference.
Describe the Object
Describe in detail how the object looks. The first part of my description I like to include an opinionated description of the object, such as this is a beautiful showpiece cluster. Be sure to give a more detailed and proper description also. With a galaxy tell how bright it is. What is its size? Tell its shape and position angle of elongation. Estimate its ratio, example 3:1 N-S. State whether the core is brighter and also if its stellar or hazy. Can you see spiral arms, dust lanes, or mottling? With dark nebula give an account of its size, shape and visibility against the background. Also note anything unusual, such as bright or dark areas. With open clusters give a brightness range of the stars. State its size, richness, compression, and whether it is detached from the background. What shape is it? I like to give a description of the clusters shape such as ngc457, an Owl, ngc7510 little Andromeda. If that is not applicable give a general description of the clusters shape round, triangle or elongated or what not. With Globular clusters give a brightness estimate. What shape is it, round or oblong and how big is it? Is the cluster resolved throughout, just at the edges or not at all? Is it brighter in the center? Also tell if you see anything unusual. With nebula tell how bright it is against the background. Are parts of it brighter or darker than the rest? What shape is it? Are there any stars near or in the nebula? Also state whether a nebula filter was used and what kind. Can the nebula be seen without the filter? With planetary nebula tell its shape. Was it difficult to identify from the nearby stars? Is there a central star visible? How bright is it? Can it be seen without a nebula filter? In general tell everything you can about the object.
Tips
Take a tape recorder with you. This will make it easier to record your notes. Also you won't have to find a pencil or ruin your dark adaptation with a flashlight. Keep your notes organized. Have a log book or use a computer for organization and storage. I use Skytools to store my notes this works very well. The most important tip is to make it fun. It is a great pleasure to see your observations published, used to get a certificate, or look back on in the future.
Back