English
Related papers

Related papers: Equator to Pole Solar Chromospheric Differential R…

200 papers

Chromospheric differential rotation is a key component in comprehending the atmospheric coupling between the chromosphere and the photosphere at different phases of the solar cycle. In this study, we therefore utilize the newly calibrated…

The study of the differential rotation in the chromosphere of the Sun is of significant importance as it provides valuable insights into the rotational behaviour of the solar atmosphere at higher altitudes and the coupling mechanism between…

Solar and Stellar Astrophysics · Physics 2024-12-25 Dibya Kirti Mishra , Srinjana Routh , Bibhuti Kumar Jha , Subhamoy Chatterjee , Dipankar Banerjee

We have analysed the Ca-K images obtained at Kodaikanal Observatory as a function of latitude and time for the period of 1913 - 2004 covering the Solar Cycle 15 to 23. We have classified the chromospheric activity into plage, Enhanced…

Solar and Stellar Astrophysics · Physics 2021-03-31 Pooja Devi , Jagdev Singh , Ramesh Chandra , Muthu Priyal , Reetika Joshi

The Ca-K spectroheliograms obtained at the Kodaikanal observatory (KO) are used to generate a uniform time series using the equal contrast technique (ECT) to study the long and short-term variation in the solar chromosphere. The percentage…

Solar and Stellar Astrophysics · Physics 2023-03-08 Muthu Priyal , Jagdev Singh , Belur Ravindra , G. Sindhuja

The rotational profile of the Sun is considered to be one of the key inputs in a solar dynamo model. Hence, precise and long-term measurements of this quantity is important for our understanding of solar magnetism and its variability. In…

Solar and Stellar Astrophysics · Physics 2021-02-02 Bibhuti Kumar Jha , Aditya Priyadarshi , Sudip Mandal , Subhamoy Chaterjee , Dipankar Banerjee

The Ca II K filtergrams from Kodaikanal Solar Observatory have been used to study the solar activity. The images are dominated by the chromospheric network and plages. Programs have been developed to obtain the network and plage indices…

Solar and Stellar Astrophysics · Physics 2015-06-17 K. P. Raju , Jagdev Singh

Solar plages, which are bright regions on the Sun's surface, are an important indicator of solar activity. In this study, we propose an automated algorithm for identifying solar plages in Ca K wavelength solar data obtained from the…

Solar and Stellar Astrophysics · Physics 2023-07-17 Sarvesh Gharat , Bhaskar Bose , Abhimanyu Borthakur , Rakesh Mazumder

In our previous article (Priyal et al. in Solar Phys. 289, 127, 2014) we have discussed the details of observations and methodology adopted to analyze the Ca-K spectroheliograms obtained at the Kodaikanal Observatory (KO) to study the…

Solar and Stellar Astrophysics · Physics 2017-07-04 Muthu Priyal , Jagdev Singh , Ravindra Belur , Somasundaram Kameshwaran Rathina

Chromospheric plages are distributed between mid-latitude and the Equator and never close to the Poles. Therefore, we suspect that the inclination angle of the solar rotation axis has an impact on the observable chromospheric emission. We…

Solar and Stellar Astrophysics · Physics 2024-10-16 G. Vanden Broeck , S. Bechet , G. Rauw , F. Clette

Solar prominences are structures of importance because of their role in polar field reversal. We study the long-term variation of the time latitude distribution of solar prominences in this article. To accomplish this, we primarily used the…

Solar and Stellar Astrophysics · Physics 2020-05-07 Subhamoy Chatterjee , Manjunath Hegde , Dipankar Banerjee , B. Ravindra , Scott W. McIntosh

Ca II K observations of the Sun have a great potential for probing the Sun's magnetism and activity, as well as for reconstructing solar irradiance. The Kodaikanal Solar Observatory (KoSO) in India, houses one of the most prominent Ca II K…

The regular observation of the solar magnetic field is available only for about last five cycles. Thus, to understand the origin of the variation of the solar magnetic field, it is essential to reconstruct the magnetic field for the past…

Although the differential rotation rate on the solar surface has long been studied using optical and extreme ultraviolet (EUV) observations, associating these measurements to specific atmospheric heights remains challenging due to the…

Solar and Stellar Astrophysics · Physics 2025-07-04 Srinjana Routh , Anshu Kumari , Vaibhav Pant , Jaydeep Kandekar , Dipankar Banerjee , Mohd. Saleem Khan , Dibya Kirti Mishra

Full-disc Ca II K photographic observations of the Sun carry direct information about the evolution of solar-plage regions for more than a century and are therefore a unique dataset for solar-activity studies. For a long time Ca II K…

Differential rotation is the basis of the solar dynamo theory. Synoptic maps of He I intensity from Carrington rotations 2032 to 2135 are utilized to investigate the differential rotation of the solar chromosphere in the He I absorption…

Solar and Stellar Astrophysics · Physics 2020-12-23 KJ Li , JC Xu , JL Xie , W Feng

We measure differential rotation and meridional flow in the Sun's surface shear layer by tracking the motions of the magnetic network seen in magnetograms from SOHO/MDI and SDO/HMI over solar cycles 23, 24, and the start of 25 (1996-2022).…

Solar and Stellar Astrophysics · Physics 2022-12-22 David H. Hathaway , Lisa A. Upton , Sushant S. Mahajan

Generally it has been considered that the plages and sunspots are the main contributors to the solar irradiance. There are small scale structures on the sun with intermediate magnetic fields that could also contribute to the solar…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jagdev Singh , B. Ravindra , R. Selvendran , P. Kumaravel , M. Priyal , T. G. Priya , K. Amareswari

Long-term variations of solar differential rotation and sunspot activity are investigated through re-analyzing the data on parameters of the differential rotation law obtained by Makarov, Tlatov, and Callebaut (1997), Javaraiah, Bertello,…

Solar and Stellar Astrophysics · Physics 2015-06-05 K. J. Li , W. Feng , X. J. Shi , J. L. Xie , P. X. Gao , H. F. Liang

Kodaikanal Observatory is a veritable treasure trove of data, with the data repository covering almost 100 years of observations. For the years 1909-2007, we use calibrated Ca II K spectroheliograms from the Kodaikanal Observatory to detect…

Solar and Stellar Astrophysics · Physics 2019-09-04 K. M. Hiremath , Shreyam Krishna , Adithya H. N , S. R. Chinmaya , Shashanka R Gurumath

Rotation is a prominent feature of the Sun, and it plays a crucial role in the generation and dynamic evolution of solar magnetic fields. The daily composite time series of Ca II K plage areas from 1907 February 1 to 2023 December 31 is…

Solar and Stellar Astrophysics · Physics 2025-12-18 N. B. Xiang , X. H. Zhao , L. H. Deng , F. Y. Li , M. Wan , S. Y. Qi
‹ Prev 1 2 3 10 Next ›