Bob Nelson's O-C files
Eclipsing Binary O-C Files
Bob Nelson has developed over 4600 O-C (Observed - Computed) files of eclipsing binaries, all in Excel format that we are hosting on our site. The purpose is to provide information on period variation for selected eclipsing binaries (for astronomers interested in a particular star) and to determine the best elements for predicting future eclipses. These elements go into eclipse prediction software, like at Shawn Dvorak's site (Bob and others help provide updated elements for Shawn).
For each star, they try to develop the best relationship possible; however ambiguities of course arrive, in these cases the most likely set of elements are displayed. The files are updated about once a year. Last Update: 2016 July 6.
Most of the information used in creating these files came from the Eclipsing Binaries Minima Database, IBVS, and SIMBAD. Tom Krajci constructed over 30 of these files. Note the addition of GSC stars to the end of each constellation's list.
The constellations of the southern hemisphere are under-represented or absent. If you would like to help in establishing and maintaining that part of the database, please contact me. (Remove dashes from email address.)
Jump to:And, Ant, Aps, Aql, Aqr, Ara, Ari, Aur, Boo, CMa, CMi, CVn, Cae, Cam, Cap, Car, Cas, Cen, Cep, Cet, Cha, Cir, Cnc, Col, Com, CrA, CrB, Crt, Cru, Crv, Cyg, Del, Dor, Dra, Equ, Eri, For, Gem, Gru, Her, Hor, Hya, Hyi, Ind, LMi, Lac, Leo, Lep, Lib, Lup, Lyn, Lyr, Men, Mic, Mon, Mus, Nor, Oct, Oph, Ori, Pav, Peg, Per, Phe, Pic, PsA, Psc, Pup, Pyx, Ret, Scl, Sco, Sct, Ser, Sex, Sge, Sgr, Tau, Tel, TrA, Tri, Tuc, UMa, UMi, Vel, Vir, Vol, Vul