Related papers: Solar physics at the Kodaikanal Observatory: A His…
An experiment for the speckle reconstruction of solar features was developed for observing the partial eclipse of the sun as viewed from Bangalore on October 24, 1995. No data could be obtained because of cloudy sky but the experimental…
The first solar neutrino experiment led by Raymond Davis Jr. showed a deficit of neutrinos relative to the solar model prediction, referred to as the "solar neutrino problem" since the 1970s. The Kamiokande experiment led by Masatoshi…
The Sun is the main energy source to Earth, and understanding its variability is of direct relevance to climate studies. Measurements of total solar irradiance exist since 1978, but this is too short compared to climate-relevant time…
The most outstanding contribution to general relativity in this era came in 1953 (published in 1955 \cite{akr}) in the form of the Raychaudhri equation. It is in 1960s that the observations began to confront the eupherial theory and thus…
The eclipse of the Sun of 1919 was fundamental in the development of physics and earns a high place in the history of science. Several players took part in this adventure. The most important are Einstein, Dyson, Eddington, the Sun, the…
This paper focuses on the observations of sunspots made by Ru{\dj}er Bo\v{s}kovi\'c in 1777. We derived the expressions needed to calculate the elements of the Sun's rotation and period from observations. We used modern ephemeris data in…
The Sun has a polar magnetic field which oscillates with the 11 year sunspot cycle. This polar magnetic field is an important component of the dynamo process which is operating in the solar convection zone and produces the sunspot cycle. We…
In 1919, Eddington and Dyson led two famous expeditions to measure the bending of light during a total solar eclipse. The results of this effort led to the first experimental confirmation of Einstein's General Relativity and contributed to…
C.V. Raman (1888-1970) was one of the pioneering scientists to have emerged from India during the colonial era. His scientific explorations were driven by his curiosity to understand wave phenomena. Naturally, optics and related physical…
Solar flares occur due to the sudden release of energy stored in active-region magnetic fields. To date, the pre-cursors to flaring are still not fully understood, although there is evidence that flaring is related to changes in the…
Differential rotation is one of the basic characteristics of the Sun, and it plays an important role in generating the magnetic fields and its activities. We investigated rotation rate using chromospheric features such as plages, enhanced…
The Sun continuously expels a fraction of its own mass in the form of a steadily accelerating outflow of ionized gas called the "solar wind." The solar wind is the extension of the Sun's hot (million-degree Kelvin) outer atmosphere that is…
Context. Solar eruptions and high flare activity often accompany the rapid rotation of sunspots. The study of sunspot rotation and the mechanisms driving this motion are therefore key to our understanding of how the solar atmosphere attains…
Time series of high-resolution images of the complex active region NOAA 10786 are studied. The observations were performed in G-band (430.5 nm) and in the nearby continuum (463.3 nm), on July 9, 2005 at the Swedish 1-meter Solar Telecope…
We study the visibility of sunspots and its influence on observed values of sunspot region parameters. We use Virtual Observatory tools provided by AstroGrid to analyse a sample of 6862 sunspot regions. By studying the distributions of…
We studied the variations of line-of-sight photospheric plasma flows during the formation phase of the penumbra around a pore in Active Region NOAA 11490. We used a high spatial, spectral, and temporal resolution data set acquired by the…
We report the observations of the solar chromosphere from a newly commissioned solar telescope at the incursion site near Pangong Tso lake in Merak (Leh/Ladakh). This new H$_{\alpha}$ telescope at the Merak site is identical to the…
The Sun is the primary source of energy for Earth and one of the main external drivers of its climate. Solar irradiance -- the radiative power emitted by the Sun and received at 1-AU -- varies on all observable timescales. It is measured as…
Sunspots are obvious observable manifestations of the toroidal magnetic field generated through the dynamo in the convection zone. They appear in different sizes, having a wide distribution in their area. We analyse the sunspot group area…
In 1911 Einstein proposed that light-bending by the Sun's gravitational field could be measured during a total solar eclipse. The first opportunity in which this measurement would be tried, was during the total solar eclipse of October 10,…