Related papers: C.Ragoonatha Chary and his Variable Stars
In this Note, which is a sequel on the Indian amateur astronomer R.G. Chandra [Biswas2011a, Biswas2011b], we have presented some documents to reveal his three-decades relationship with the American Association for Variable Stars Observers…
T. H. Astbury (1858-1922) was for many years the much-respected headmaster of a boys' junior school in the English market town of Wallingford. By night he was a dedicated amateur astronomer who enjoyed observing meteors, variable stars and…
In the present Note we have presented some documents to reveal the longstanding relationship of Indian amateur astronomer R. G. Chandra with British Astronomical Association.
G.V.Juggarow was one of the early pioneers of observational astronomy in India who built his own observatory in 1840 at Vizagapatnam. His legacy was continued by his son-in-law A.V.Nursing Row till 1892, his daughter till 1894, Madras…
Variable stars have a unique part to play in Galactic astronomy. Among the most important of these variables are the Cepheids (types I and II), the RR Lyraes and the Miras (O- and C-rich). The current status of the basic calibration of…
Stellar astronomy, fueled by massive capital investments, advances in numerical modeling and theory, is resurgent and arguably is on the verge of a magnificent renaissance. Powerful time domain optical surveys, both on ground and in space,…
Many decades ago a search for variable stars was one of the main areas of astrophysical research. Such searches, conducted with CCD detectors rather than with photographic plates, became a by-product of several projects seeking…
In the present article we provide a brief introduction to the Life and Works of Indian astronomer R. G. Chandra.
Felix de Roy (1883-1942), an internationality recognised amateur astronomer, made significant contributions to variable star research. As an active observer, he made some 91,000 visual estimates of a number of different variable stars. A…
This paper presents the Charge-Coupled Device time-series photometric observations of the open cluster NGC 1582 and its surrounding field with Johnson B, V and R filters by using Nanshan 1m telescope of Xinjiang Astronomical Observatory. 19…
The Gaia mission has observed over 2 billion stars repeatedly across the entire sky over 10 years, revealing the many astronomical objects that vary on human timescales from seconds to years. Its repeated astrometric, photometric,…
John Goodricke and Edward Pigott, working in York, England, between 1781 and 1786, determined the periods of variation of eclipsing binaries such as Algol and Beta Lyrae and speculated that the eclipses of Algol might be caused by a "dark…
Aboriginal Australians carefully observe the properties and positions of stars, including both overt and subtle changes in their brightness, for subsistence and social application. These observations are encoded in oral tradition. I examine…
A radial velocity (RV) survey to detect central stars in binary systems was carried out between 2002 and 2004. De Marco et al. (2004) reported that 10 out of 11 monitored stars exhibited strong RV variability, but periods were not detected.…
Variability in the sky has been known for centuries, even millennia, but our knowledge of it is very incomplete even at the bright end. Current technology makes it possible to built small, robotic optical instruments, to record images and…
G. B. Riccioli's 1651 Almagestum Novum contains a table of diameters of stars measured by Riccioli and his associates with a telescope. These telescopically measured star diameters are spurious, caused by the diffraction of light waves…
In November 2001 we undertook a coordinated observing campaign to study the connection between X-ray and optical variability in the weak-line T Tauri star V410Tau. The observing plan included three 15 ksec observations with Chandra using…
The Kepler space telescope has revolutionised our knowledge about exoplanets and stars and is continuing to do so in the K2 mission. The exquisite photometric precision, together with the long, uninterrupted observations opened up a new way…
A series of spectra of the RV Tauri star R Scuti taken as it rose from a deep minimum to a bright maximum during 2013 October and November reveals major changes taking place in the photosphere and outer atmosphere of the star. This may be…
Scientific research is a continuous process, and the speed of future progress can be estimated by the pace of finding explanations for previous research questions. In this observers based view of stellar pulsation and asteroseismology, we…