Abdo, A. A.A. A.AbdoAckermann, M.M.AckermannAjello, M.M.AjelloGasparrini, DarioDarioGasparrini2020-09-172020-09-172009-07-01https://hdl.handle.net/20.500.13025/2777Millisecond pulsars (MSPs) have been firmly established as a class of γ-ray emitters via the detection of pulsations above 0.1 GeV from eight MSPs by the Fermi Large Area Telescope (LAT). Using 13 months of LAT data, significant γ-ray pulsations at the radio period have been detected from the MSP PSR J0034-0534, making it the ninth clear MSP detection by the LAT. The γ-ray light curve shows two peaks separated by 0.274 ± 0.015 in phase which are very nearly aligned with the radio peaks, a phenomenon seen only in the Crab pulsar until now. The ⩾ 0.1 GeV spectrum of this pulsar is well fit by an exponentially cutoff power law with a cutoff energy of 1.8 ± 0.6 ± 0.1 GeV and a photon index of 1.5 ± 0.2 ± 0.1, first errors are statistical and second are systematic. The near-alignment of the radio and γ-ray peaks strongly suggests that the radio and γ-ray emission regions are co-located and both are the result of caustic formation.engamma rays: generalpulsars: generalpulsars: individualjournal articlehttp://dx.doi.org/10.1088/0004-637X/712/2/957https://iopscience.iop.org/article/10.1088/0004-637X/712/2/95754dcce0a8580fe1368eeb340