bs shylaja - Academia.edu (original) (raw)
Papers by bs shylaja
Journal of astronomical history and heritage, Mar 1, 2024
This is a study of a rare seventeenth century palm-leaf manuscript named the Grahaṇamukura, which... more This is a study of a rare seventeenth century palm-leaf manuscript named the Grahaṇamukura, which has been carefully preserved in a private collection for more than 400 years. This manuscript was used to calculate eclipses, and has bilingual text, with verses in Sanskrit and a commentary in Kannaḍa, a southern Indian language. It is a handy manual for the prediction of eclipses following the methods prescribed in treatises. In the absence of the name of the author anywhere in the text, we conjecture that it was written by the fatherson duo, Demaṇa Joyisaru and Śaṅkaranārāyaṇa Joyisaru of Sringeri. In this paper the contents of the text are summarized.
Indian Journal of History of Science, Aug 31, 2023
Indian Journal of History of Science
Journal of Astronomical History and Heritage
A rare painting depicting an almost total solar eclipse has been traced to have originated from K... more A rare painting depicting an almost total solar eclipse has been traced to have originated from Kangra in northern India. The artist used the eclipse in his biographical sketch of Lord Krishna. In this paper we attempt to identify the eclipse that may have inspired him, based on the observing site and probable time of the eclipse.
Current Science, Nov 25, 2019
Proceedings of Indian National Science Academy, 2014
Historical Note: Records of Celestial Events by European Travellers during Medieval Times
Kodaikanal Observatory Bulletins, 1979
Current Science, Oct 25, 2019
The Growth and Development of Astronomy and Astrophysics in India and the Asia-Pacific Region, 2019
Based on their listed coordinates, we have compiled a catalogue of more than 100 bright stars inc... more Based on their listed coordinates, we have compiled a catalogue of more than 100 bright stars included in various texts from the Surya Siddhanta to the Siddhanta Darpana by Chandrashekhara Samanta in the nineteenth century. Using the 27 nakshatras on the ecliptic, which fix the position of the Solar System bodies, the coordinates were matched for the epochs of the catalogues. This resolved some ambiguity in respect of the identification of faint stars and provided a means to extend the method to other stars outside the zodiac. We have specifically chosen those lists that are characterized by observations, which are highlighted in the discussion. Our study reveals that a scale similar to the magnitude scale of brightness (currently in use) was in vogue in ancient Indian astronomy. Stars used by navigators, not listed with coordinates but as practical tools, are also included. The origin of the names are described—some were indigenous, and some were borrowed from the Arabs and later from the Europeans. In this preliminary study we provide an overview of the positions of the stars.
History of Science in South Asia, 2020
From a private collection of palm leaf manuscripts the text Gaṇithagannaḍi has been unearthed and... more From a private collection of palm leaf manuscripts the text Gaṇithagannaḍi has been unearthed and studied. The contents follow the traditional texts with all the chapters starting from the calculation of ahargaṇas to the predictions of eclipses. The text presents a unique method of calculation which the author, Viddaṇācārya, declares to be his own invention. In this paper, the procedures are described with the help of the elaborate commentary, written in Kannaḍa language, by Shankaranārāyaṇa Jōisaru of Sringeri. This paper highlights the uniqueness of the procedure for calculating the ahargaṇa and the dhruvās for the positions of planets.
White Dwarfs, 2003
An attempt has been made here to seek the origin of the magnetic white dwarfs in Cataclysmic Vari... more An attempt has been made here to seek the origin of the magnetic white dwarfs in Cataclysmic Variables. Following the suggestion made in the case of isolated white dwarfs, we look at the possibility of binaries with magnetic A type stars known as chemically peculiar stars as progenitors of MCVs. The evolution of the binary is discussed and compared with the available statistics.
... Switzerlqnd. It is my duty to acknowledge the staff of the Kaval ur Observatory, especially M... more ... Switzerlqnd. It is my duty to acknowledge the staff of the Kaval ur Observatory, especially Mr.K.Kuppuswamy, Mr.K.Jayakumar, ... SundClra Rao, brothers, Jagadeesha Chandra and RamaPrakash, sisters, Urna Devi and Nethravathi, and brother in law, Abhirarna ...
Journal of Astrophysics and Astronomy, 2019
Indian siddhāntic texts are well known for their indigenous approach to solutions of problems in ... more Indian siddhāntic texts are well known for their indigenous approach to solutions of problems in astronomy which also speaks of their expertise in mathematics. The text Sūryasiddhānta is considered as an authority and we come across a number of texts as commentaries on this text. They range from 8th Century CE to 19th century CE. The study of the stars that have been listed in the text appears relatively easy for the 27 stars of the zodiac. However, there are other stars for which optical identifications are not easy. Here we present possible identifications for two stars calledĀpa and Apām. vatsa, in the constellation of Virgo. We use the NASA Skyview Survey and other catalogues to see if these two correspond to variable stars.
It is well known that ancient Indian calendar dwelled on the 27 nakśatra system for fixing the po... more It is well known that ancient Indian calendar dwelled on the 27 nakśatra system for fixing the positions of the sun, moon and the planets. Several attempts to identify these 27 stars in the sky have yielded very precise results for stars bright enough not to be misidentified, which is not so for the fainter ones. The basis for identification is the coordinate system available in the texts. Here, we try to understand the ambiguity and offer a possible solution by using the measured coordinates, which have not been utilized for this purpose so far. This also provides clues on the techniques used for measuring the coordinates.
International Astronomical Union Colloquium, 1993
A comparison of various physical parameters of the normal A stars with those obtained by using th... more A comparison of various physical parameters of the normal A stars with those obtained by using the peculiarity-free zones of Ap stars indicate that the peculiar A stars may be treated as normal stars as far as their effective temperatures, radii, bolometric corrections and the mass range are concerned.
Journal of astronomical history and heritage, Mar 1, 2024
This is a study of a rare seventeenth century palm-leaf manuscript named the Grahaṇamukura, which... more This is a study of a rare seventeenth century palm-leaf manuscript named the Grahaṇamukura, which has been carefully preserved in a private collection for more than 400 years. This manuscript was used to calculate eclipses, and has bilingual text, with verses in Sanskrit and a commentary in Kannaḍa, a southern Indian language. It is a handy manual for the prediction of eclipses following the methods prescribed in treatises. In the absence of the name of the author anywhere in the text, we conjecture that it was written by the fatherson duo, Demaṇa Joyisaru and Śaṅkaranārāyaṇa Joyisaru of Sringeri. In this paper the contents of the text are summarized.
Indian Journal of History of Science, Aug 31, 2023
Indian Journal of History of Science
Journal of Astronomical History and Heritage
A rare painting depicting an almost total solar eclipse has been traced to have originated from K... more A rare painting depicting an almost total solar eclipse has been traced to have originated from Kangra in northern India. The artist used the eclipse in his biographical sketch of Lord Krishna. In this paper we attempt to identify the eclipse that may have inspired him, based on the observing site and probable time of the eclipse.
Current Science, Nov 25, 2019
Proceedings of Indian National Science Academy, 2014
Historical Note: Records of Celestial Events by European Travellers during Medieval Times
Kodaikanal Observatory Bulletins, 1979
Current Science, Oct 25, 2019
The Growth and Development of Astronomy and Astrophysics in India and the Asia-Pacific Region, 2019
Based on their listed coordinates, we have compiled a catalogue of more than 100 bright stars inc... more Based on their listed coordinates, we have compiled a catalogue of more than 100 bright stars included in various texts from the Surya Siddhanta to the Siddhanta Darpana by Chandrashekhara Samanta in the nineteenth century. Using the 27 nakshatras on the ecliptic, which fix the position of the Solar System bodies, the coordinates were matched for the epochs of the catalogues. This resolved some ambiguity in respect of the identification of faint stars and provided a means to extend the method to other stars outside the zodiac. We have specifically chosen those lists that are characterized by observations, which are highlighted in the discussion. Our study reveals that a scale similar to the magnitude scale of brightness (currently in use) was in vogue in ancient Indian astronomy. Stars used by navigators, not listed with coordinates but as practical tools, are also included. The origin of the names are described—some were indigenous, and some were borrowed from the Arabs and later from the Europeans. In this preliminary study we provide an overview of the positions of the stars.
History of Science in South Asia, 2020
From a private collection of palm leaf manuscripts the text Gaṇithagannaḍi has been unearthed and... more From a private collection of palm leaf manuscripts the text Gaṇithagannaḍi has been unearthed and studied. The contents follow the traditional texts with all the chapters starting from the calculation of ahargaṇas to the predictions of eclipses. The text presents a unique method of calculation which the author, Viddaṇācārya, declares to be his own invention. In this paper, the procedures are described with the help of the elaborate commentary, written in Kannaḍa language, by Shankaranārāyaṇa Jōisaru of Sringeri. This paper highlights the uniqueness of the procedure for calculating the ahargaṇa and the dhruvās for the positions of planets.
White Dwarfs, 2003
An attempt has been made here to seek the origin of the magnetic white dwarfs in Cataclysmic Vari... more An attempt has been made here to seek the origin of the magnetic white dwarfs in Cataclysmic Variables. Following the suggestion made in the case of isolated white dwarfs, we look at the possibility of binaries with magnetic A type stars known as chemically peculiar stars as progenitors of MCVs. The evolution of the binary is discussed and compared with the available statistics.
... Switzerlqnd. It is my duty to acknowledge the staff of the Kaval ur Observatory, especially M... more ... Switzerlqnd. It is my duty to acknowledge the staff of the Kaval ur Observatory, especially Mr.K.Kuppuswamy, Mr.K.Jayakumar, ... SundClra Rao, brothers, Jagadeesha Chandra and RamaPrakash, sisters, Urna Devi and Nethravathi, and brother in law, Abhirarna ...
Journal of Astrophysics and Astronomy, 2019
Indian siddhāntic texts are well known for their indigenous approach to solutions of problems in ... more Indian siddhāntic texts are well known for their indigenous approach to solutions of problems in astronomy which also speaks of their expertise in mathematics. The text Sūryasiddhānta is considered as an authority and we come across a number of texts as commentaries on this text. They range from 8th Century CE to 19th century CE. The study of the stars that have been listed in the text appears relatively easy for the 27 stars of the zodiac. However, there are other stars for which optical identifications are not easy. Here we present possible identifications for two stars calledĀpa and Apām. vatsa, in the constellation of Virgo. We use the NASA Skyview Survey and other catalogues to see if these two correspond to variable stars.
It is well known that ancient Indian calendar dwelled on the 27 nakśatra system for fixing the po... more It is well known that ancient Indian calendar dwelled on the 27 nakśatra system for fixing the positions of the sun, moon and the planets. Several attempts to identify these 27 stars in the sky have yielded very precise results for stars bright enough not to be misidentified, which is not so for the fainter ones. The basis for identification is the coordinate system available in the texts. Here, we try to understand the ambiguity and offer a possible solution by using the measured coordinates, which have not been utilized for this purpose so far. This also provides clues on the techniques used for measuring the coordinates.
International Astronomical Union Colloquium, 1993
A comparison of various physical parameters of the normal A stars with those obtained by using th... more A comparison of various physical parameters of the normal A stars with those obtained by using the peculiarity-free zones of Ap stars indicate that the peculiar A stars may be treated as normal stars as far as their effective temperatures, radii, bolometric corrections and the mass range are concerned.