Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/7382
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dc.contributor.authorHiremath, K. M-
dc.contributor.authorRozelot, J. P-
dc.contributor.authorSarp, V-
dc.contributor.authorKilcik, A-
dc.contributor.authorPavan, D. G-
dc.contributor.authorGurumath, S. R-
dc.date.accessioned2020-11-26T15:19:29Z-
dc.date.available2020-11-26T15:19:29Z-
dc.date.issued2020-03-10-
dc.identifier.citationThe Astrophysical Journal, Vol. 891, No. 2, 151en_US
dc.identifier.issn0004-637X-
dc.identifier.urihttp://prints.iiap.res.in/handle/2248/7382-
dc.descriptionRestricted Accessen_US
dc.description.abstractThe Kodaikanal Archive Program (India) is now available to the scientific community in digital form as daily digitized solar white light pictures, from 1923 to 2011. We present here the solar radius data, obtained after a painstaking effort to remove all effects that contribute to the error in their measurements (limb darkening, distortion of the objective lens, refraction, other instrumental effects, etc.). These data were analyzed to reveal any significant periodic variations, after applying a multi-taper method with red noise approximation and the Morlet wavelet transform analysis. After removing obvious periodic variations (such as solar rotation and Earth annual rotation), we found a possible cycle variation at 11.4 yr, quasi biennial oscillations at 1.5 and 3.8 yr, and Rieger-type periodicity at ≈159, 91, and 63 days. Another $\approx 7.5$ yr periodicity (as a mean) resulting from two other main periodicities detected at 6.3–7.8 yr can be identified as an atmospheric component. The detrending data show, over a mean radius of $959\buildrel{\prime\prime}\over{.} 7\pm 0\buildrel{\prime\prime}\over{.} 5$, a residual of less than ≈(−)1 mas over the time period of analysis: if not spurious, this estimate indicates a faint decline, but probably confirms more the constancy of the solar diameter during the considered ranging time, within instrumental and methodological limits. The Kodaikanal long quality observations contribute to international efforts to bring past solar data measurements to the community to further explore issues, for instance, those of the luminosity/radius properties that could be used to pinpoint the "seat of the solar cycle."en_US
dc.language.isoenen_US
dc.publisherIOP Publishingen_US
dc.relation.urihttps://doi.org/10.3847/1538-4357/ab6d08-
dc.rights© The American Astronomical Society-
dc.subjectSolar radiusen_US
dc.subjectKodaikanal Archive Programen_US
dc.titleNearly Century-scale Variation of the Sun’s Radiusen_US
dc.typeArticleen_US
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