1998/02/12 by R. Mignani, R. P. Mignani, Mignani, R. P. +4
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Geophysics and Gravity Measurements #Historical Astronomy and Related Studies #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9802158
4 pages, 1 latex figure included, Accepted for publication on Astronomy and Astrophysics Letters
arxiv created 1998/02/12 · openalex publication_date 1998/02/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
New optical and near-UV HST observations of Geminga are presented. When compared with previous ground-based and HST imaging, the data confirm and better define the presence of an emission feature centered at 6,000 Angstrom and superimposed on the thermal continuum best fitting the extreme-UV/soft X-ray data. This feature may be interpreted in terms of cyclotron emission originated from a mixture of H/He ions in the neutron star's atmosphere. In the case of pure Hydrogen, the feature wavelength would imply a magnetic field of order 3-5 10d11 G, consistent with the value deduced from the dynamical parameters of the pulsar. If due to a cyclotron emission, the observation of this feature would represent the first case of an in situ measurement of the surface magnetic field of an isolated neutron star.