Winston-Salem Astronomical League

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Observing Logs, Tally Sheets, etc.

Session Observing Log - This one-page Word 2000 document is an observing log you can use to record objects you have located and observed during an observing session. You will typically use one or several of these sheets during each evening's observation, so print plenty of them and keep plenty of blank ones in your observing notebook. Some of the items deserve explanation:

Date - we use the local date because we find it less confusing. You may want to use the UT date and time.

Lunar status - record the state of the moon during your session. For example, we might fill out this item as "rises 0223 day following; 45% illuminated".

Location - PM is the Pilot Mountain State Park parking lot; KE is the King Estate in Walnut Cove; FG is Fancy Gap; Home is your own home.

Observer - We left our own initials in place in this form, along with a space for someone else's name (we frequently give log sheets to other people). If you're the only observer in your family, just fill your own name in here.

Temperature, Winds, RH - we generally fill in the temperature, wind speed, and relative humidity at the start of the session. If any of those change significantly, we'll write in a range, e.g., "3-5 MPH, later 8-10", or "50% RH, later increasing to 85%"

Transparency - we use a 10 point scale, with 1 being heavy haze, 5 being average conditions, and 10 crystal clarity. Others use other scales. Whatever you want to use is fine as long as you're consistent.

Seeing - Again, we use a 10 point scale, with 1 being terrible atmospheric stability and 10 being rock solid viewing. Note that seeing has nothing to do with transparency, and in fact the best seeing often occurs when a heavy haze exists. Seeing has to do only with how stable the atmosphere is. If you can see stars twinkling, the seeing is bad no matter how clear the night.

Clouds - we estimate cloud cover on a 10ths basis. That is, no cloud cover is 0/10, complete cloud cover is 10/10. If the clouds are evenly distributed, anything more than 2/10 or 3/10 makes it difficult to observe because the clouds make it hard to locate constellations and finder stars.

LM - this is limiting magnitude at zenith, which depends on transparency, light pollution, altitude, and how good the observer's night vision and dark adaptation is. Even under the same conditions, LM can vary a full magnitude or more from observer to observer. This field is your personal number for LM.

As far as the individual object lines, note the following:

Object - we recommend you record objects by their NGC number when possible. For example, if you are logging M42, the Great Nebula in Orion, rather than recording it simply as "M42", we suggest you record it as "NGC 1976 (M42)" or something similar. That's because some objects appear on more than one observing club list. Observing a particular object once gets you credit not just for the observing club you're working on, but for the other clubs that include that object as well. If you have the objects recorded by NGC it's a lot easier to make sure you don't overlook them when you're transferring your observations to your consolidated tally sheets. Incidentally, don't feel compelled to limit yourself to one line per object. Use several lines if you need more space for recording your comments. Leave a blank line between objects. Whatever.

Time - we always use local time, although some people prefer UT.

Scope and Ocular - the "scope" you used to observe the object, which may be your naked eye, a binocular, your own scope, or one that belongs to someone else. We have a couple lines of abbreviations at the bottom of our log sheets, so that instead of writing down "10 inch f/5 Dob" we can just write "10" and know later what we used. Same thing for "Ocular", which is the eyepiece you use.

Note that there's nothing official about this log sheet. It captures the data required by most of the AL clubs. (There are a couple exceptions, such as the Double Star club, which requires drawings, so always verify that you're capturing all the data necessary when you start pursuing a particular club). Please feel free to modify this sheet however suits you. As long as you capture the necessary data, it doesn't much matter what form it's in.

Messier Club/Binocular Messier Club Log - This two-page Word 2000 document is a tally sheet that lists all Messier Club objects and Binocular Messier Club objects sorted by constellation, with space to record the date and time you observed each object. Those of the objects that are possible with 7X35, 7X50, or 10X50 binoculars are coded E (Easy), T (Tougher), or C (Challenge), using the Astronomical League's ratings. Logging 50 of the binocular objects on this list entitles you to the Binocular Messier Club pin and certificate. Logging 70 of the objects (including any you have logged for the Binocular Messier Club) entitles you to the standard Messier Club certificate. Logging all 110 objects entitles you to the Honorary Messier Club pin and certificate. [This log sheet is not intended for recording your original observation data. Use Session Observing Log sheets for that. This log sheet is intended to consolidate data from your various session log sheets to make it easy to keep track of which objects you still need to observe to gain your Messier Club and Binocular Messier Club certificates.]

Deep Sky Binocular Club Log - This three page Word 2000 document is a tally sheet that lists all Deep Sky Binocular Club objects sorted by constellation, with space to record the date and time you observed each object. [This log sheet is not intended for recording your original observation data. Use Session Observing Log sheets for that. This log sheet is intended to consolidate data from your various session log sheets to make it easy to keep track of which objects you still need to observe to gain your Deep Sky Binocular Club certificate.]