• D. A. Leahy

      Articles written in Journal of Astrophysics and Astronomy

    • The 59 s periodicity of 2CG 195 + 4 (Geminga) and a low-mass binary model

      D. A. Leahy S. V. Damle S. Naranan

      More Details Abstract Fulltext PDF

      An examination of the existing period searches for 2CG195 + 4 leads to the conclusion that the 59 second periodicity is highly significant only for the 1981 March 17–18 detection of Bignami, Caraveo & Paul (1984). The statistical significance is increased substantially if the pulsation period is half the previously reported value. The period derivative is not well determined. Here we propose that 2CG 195 + 4 is a neutron star powered by accretion from a low (≲ 1M) mass main-sequence companion. A distance of a few hundred pc would imply that the neutron star is a fast rotator and is spinning down.

    • Infrared observations of symbiotic stars

      A. G. Ananth D. A. Leahy

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      Near infrared measurements in the J, H and K bands have been carried out for a number of symbiotic stars with the 1.5 m telescope at the Rothney Astrophysical Observatory (RAO). A comparison with the earlier observations shows that the S-type symbiotic stars do not have any significant variation in the infrared flux over the past five years. However a small variation ∼ 0.3 magnitude in the infrared flux has been detected for CH Cygni. The observations of HM Sagittae show large decreases in the infrared flux compared to the previous measurements. The variability in the infrared fluxes of both these objects could be attributed to a variation in the temperature due to the cooling of the dust shell. The variability observed for V1016 Cygni is found consistent with the previous measurements.

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    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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