| Atomic Mass | Mass Excess |
| 258.09842576938 amu | 91.683 MeV |
| Level energy (MeV) | Spin & parity | Half-life | Mode of decay | Branch ratio (%) | Decay energy (MeV) |
| Ground state | (8-) | 51.5 D 0.3 | A | 100 | 7.271 |
| Ground state | (8-) | 51.5 D 0.3 | SF | <=0.00 | 3 7.271 |
| Ground state | (1-) | 57.0 M 0.9 | EC | >=70.00 | 1.26 |
| Ground state | (1-) | 57.0 M 0.9 | SF | <=30.00 | 1.26 |
| Ground state | (1-) | 57.0 M 0.9 | A | 1.2 | 7.271 |
There is no gamma-rays or the intensities are so weak!