The Simple Observing Log (TSOL)

TSOL is now available in German! Thank you to Christian Schmidt for his translation.

TSOL ist jetzt auf Deutsch vorhanden! Danke zu Christian Schmidt für seine Übersetzung.

Are you a CCD astrophotographer? TSOL now includes fields to support CCD photo data!

any thanks to Florent Poiget of France for his many helpful suggestions and beta-testing.

Are you a variable star observer? TSOL now includes fields to support American Association of Variable Star Observers’ (AAVSO) data!

What is TSOL?

The Simple Observing Log (TSOL) is intended as a place where you can keep track of all your star-gazing information.

You may fill out forms for all the objects you intend to view in a session, then use the forms to keep track of your sucess, or you may observe as you always have, and record your observations during or after your session. After you’re done, you can view and print your observing records sorted by date or by object.

There’s even a space where you can sketch your observations on the page, or place scans of your sketches after you’re done. An “astrophoto” section for each observation lets astrophotographers keep track of their exposures as well.

When you want to use TSOL in the field, simply choose “Nightvision Mode” to switch to a vision-saving red display!

(Screen shot – click to see larger image)

The Simple Observing Log is “giveware”: If you like it, I ask that you give it to a friend. Also, “give” me an e-mail and let me know what you think. Your suggestions are invaluable, and will help me to improve TSOL in the future.

Download TSOL

TSOL Standalone Version

Windows Application


Mac Application


TSOL Database Version

(requires Filemaker Pro)

Windows Database


Mac Database


Deutsche Version (German Version)

Thanks to Christian Schmidt for translating TSOL!

For Filemaker Pro version, click here. (35K)

Windows Application


Mac Application


The Mac and Windows versions of TSOL are compliant with the American Association of Variable Star Observers (AAVSO) data format. At the Association’s request, I’ve developed a version of TSOL that allows you to enter Variable Star tracking info and export it in the required format. The AAVSO functionality includes a Julian date calculator! As usual, the database version requires Filemaker Pro, the application version does not.

For more information, visit the AAVSO Web site:

If you enjoy this software, please contribute to help support future development by clicking the PayPal link below. (Some ad-blockers may hide the link.)