| Predicted | Observed periods (s) | Observed periods (s) | Observed periods (s) |  |
| Period (s) | (XCOV18) | (XCOV13) | Archival data | |
| 1405.8 | 1390.8 | +18? | ||
| 1357.8 | 1347.9 | 1353.7 | +17? | |
| 1309.8 | 1308.7 | +16? | ||
| 1261.8 | +15? | |||
| 1213.8 | +14? | |||
| 1165.8 | +13? | |||
| 1117.8 | +12? | |||
| 1069.8 | 1070.8, 1067.5, 1065.0 | 1064.5 | +11 | |
| 1021.8 | +10 | |||
| 973.8 | 979.2-971.6 | +9 | ||
| 925.8 | 933.2, 930.6 | 932.5 | +8 | |
| 877.8 | +7 | |||
| 829.8 | +6 | |||
| 781.8 | 799.1-792.7 | 796.5, 781.0 | +5 | |
| 733.8 | 748.5 | +4 | ||
| 685.8 | 689.3 | +3 | ||
| 637.8 | 659.5 | 657.4 | 628 | +2 |
| 589.8 | 598.6, 597.1, 596.8 | 597.0 | +1 | |
| 541.8 | 542.4, 541.8, 540.9 | 541.0 | 0 | |
| 493.8 | 493.2, 494.2 | 494 | -1 | |
| 445.8 | 449.8 | -2 | ||
| 397.8 | 382.5 | 382.5 | -3 |
modes in HL Tau 76 with 
s.