Sengupta, Anand et al.Anand et al.Sengupta2025-08-312025-08-312019-04-0110.3847/1538-4357/ab0e152-s2.0-85064437212https://repository.iitgn.ac.in/handle/IITG2025/23326We present the results of a search for short- and intermediate-duration gravitational-wave signals from four magnetar bursts in Advanced LIGO's second observing run. We find no evidence of a signal and set upper bounds on the root sum squared of the total dimensionless strain (h <inf>rss</inf>) from incoming intermediate-duration gravitational waves ranging from 1.1 ×10^-22 at 150 Hz to 4.4 ×10^-22 at 1550 Hz at 50% detection efficiency. From the known distance to the magnetar SGR 1806-20 (8.7 kpc), we can place upper bounds on the isotropic gravitational-wave energy of 3.4 ×10⁴⁴ erg at 150 Hz assuming optimal orientation. This represents an improvement of about a factor of 10 in strain sensitivity from the previous search for such signals, conducted during initial LIGO's sixth science run. The short-duration search yielded upper limits of 2.1 ×10⁴⁴ erg for short white noise bursts, and 2.3 ×10⁴⁷ erg for 100 ms long ringdowns at 1500 Hz, both at 50% detection efficiency.truegravitational waves | stars: magnetarsArticlehttps://iopscience.iop.org/article/10.3847/1538-4357/ab0e15/pdf153843571 April 20194016341WOS:000463537200001