• K. K. Scaria

      Articles written in Journal of Astrophysics and Astronomy

    • Mass segregation in globular clusters

      K. K. Scaria M. K. V. Bappu

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      Photoelectric aperture-photometry ofω Cen inU, B, V, R andI bands has established that the cluster is bluer between 2 arcmin and 4 arcmin from the centre, than it is elsewhere. The difference inB - I colour between the centre and this blue zone is ≃ 0.45 mag. The core radius is found to be dependant on the wavelength band chosen for observation, the smallest core radius being for theI band. Equidensitometry ofω Cen inB, V and infrared bands shows a wavelength dependence with the cluster being nearly spherical in the infrared band. It shows a maximum ellipticity around 3 arcmin from the cluster centre. The blue contribution in this zone comes from both a diffuse background of unresolved stars and an increase in the relative abundance of horizontal branch (HB) stars. The similarity between the diffuse background and the HB stars has been demonstrated. A photographic subtraction technique is used to study the distribution of HB stars in the cluster.

      Results of equidensitometry of the cluster 47 Tuc, obtained in the present study, are compared with the earlier results of photoelectric photometry. Here too an increase in ellipticity is associated with an increase in the blueness of the cluster. All globular clusters studied so far for ellipticity show a similarity in the dependence of the ellipticity on the distance from the centre. The ellipticity has small values near the centre and in the outer regions, with the maximum value in between. We suggest that the red stars in globular clusters have a nearly spherical distribution. The blue stars form a bulge around the core with a more elliptical distribution and a different orientation. A similarity between the ellipticity aspects of both the globular clusters and rotation in the nucleus of M 31 is pointed out; the M 31 nucleus may thus show a bluer colour and smaller UV excess around the region where the rotation curve shows a peak.

    • Corrigendum

      K. K. Scaria M. K. V. Bappu

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    • Brightness, polarization and electron density of the solar corona of 1980 february 16

      K. R. Sivaraman M. Jayachandran K. K. Scaria G. S. D. Babu S. P. Bagare A. P. Jayarajan

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      During the eclipse of 1980 February 16 we photographed the solar corona at an effective wavelength of 6300 å. Using a quadruple camera we also obtained the coronal pictures in polarized light for four Polaroid orientations. We have used these observations to derive the coronal brightness and polarization and from these the electron densities in the corona out to a distance of about 2.5 R⊙ from the centre of the disc. The coronal brightness matches well with that of the corona of 1958 October 12.

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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.

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      Posted on July 25, 2019

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