Rapid Photometric Variability Of The Symbiotic System CH Cyg During 2008–15

2015 ◽  
Vol 71-72 ◽  
pp. 107-108
Author(s):  
S. Shugarov ◽  
A. Skopal ◽  
M. Sekeráš ◽  
G. Komissarova ◽  
M. Wolf
Keyword(s):  
Symbiotic System ◽  
Photometric Variability

scholarly journals Spectroscopy and Optical/IR Photometry of the Cataclysmic Variable CPD-48° 1577

1984 ◽  
Vol 80 ◽  
pp. 145-151
Author(s):  
W. Wargau ◽  
A. Bruch ◽  
H. Drechsel ◽  
J. Rahe ◽  
R. Schoembs
Keyword(s):  
Emission Line ◽  
Cataclysmic Variable ◽  
Line Profiles ◽  
Photometric Variability ◽  
Ir Photometry

AbstractThe photometric variability of CPD-48°1577 in the optical and IR ranges is discussed. The structure and variation of prominent emission line profiles are investigated. An estimate of the distance is given.

scholarly journals Learning about Stellar Dynamos from Long–term Photometry of Starspots

1991 ◽  
Vol 130 ◽  
pp. 353-369 ◽  
Author(s):  
Douglas S. Hall
Keyword(s):  
Differential Rotation ◽  
Rotation Period ◽  
Turnover Time ◽  
Rotating Stars ◽  
Photometric Variability ◽  
Solar Type ◽  
Magnetic Cycles ◽  
The Many ◽  
Rapidly Rotating Stars

AbstractSpottedness, as evidenced by photometric variability in 277 late-type binary and single stars, is found to occur when the Rossby number is less than about 2/3. This holds true when the convective turnover time versus B–V relation of Gilliland is used for dwarfs and also for subgiants and giants if their turnover times are twice and four times longer, respectively, than for dwarfs. Differential rotation is found correlated with rotation period (rapidly rotating stars approaching solid-body rotation) and also with lobe-filling factor (the differential rotation coefficient k is 2.5 times larger for F = 0 than F = 1). Also reviewed are latitude extent of spottedness, latitude drift during a solar-type cycle, sector structure and preferential longitudes, starspot lifetimes, and the many observational manifestations of magnetic cycles.

scholarly journals Long-Term Multicolour Photometry of the Young Stellar Objects FHO 26, FHO 27, FHO 28, FHO 29, and V1929 Cygni

2015 ◽  
Vol 32 ◽  
Author(s):  
S. I. Ibryamov ◽  
E. H. Semkov ◽  
S. P. Peneva
Keyword(s):  
Gulf Of Mexico ◽  
Young Stellar Objects ◽  
Main Sequence Stars ◽  
Stellar Objects ◽  
Photometric Variability ◽  
The North ◽  
Dense Molecular Cloud ◽  
Photometric Observations ◽  
All Optical

AbstractResults from long-term multicolour optical photometric observations of the pre-main-sequence stars FHO 26, FHO 27, FHO 28, FHO 29, and V1929 Cyg collected during the period from 1997 June to 2014 December are presented. The objects are located in the dense molecular cloud L935, named ‘Gulf of Mexico’, in the field between the North America and Pelican nebulae. All stars from our study exhibit strong photometric variability in all optical passbands. Using our BVRI observations and data published by other authors, we tried to define the reasons for the observed brightness variations. The presented paper is a part of our long-term photometric study of the young stellar objects in the region of ‘Gulf of Mexico’.

A Review on Algal-Bacterial Symbiotic System for Effective Treatment of Wastewater

Chemosphere ◽  
2021 ◽  
pp. 129540
Author(s):  
A. Saravanan ◽  
P. Senthil Kumar ◽  
Sunita Varjani ◽  
S. Jeevanantham ◽  
P.R. Yaashikaa ◽  
...  
Keyword(s):  
Effective Treatment ◽  
Symbiotic System

scholarly journals Astrometric and Photometric Variability in Quasars

2009 ◽  
Vol 5 (S267) ◽  
pp. 103-103
Author(s):  
A. H. Andrei ◽  
S. Bouquillon ◽  
J. L. Penna ◽  
F. Taris ◽  
S. Anton ◽  
...  
Keyword(s):  
Strong Support ◽  
Optical Emission ◽  
Optical Observations ◽  
Massive Black Hole ◽  
Full Account ◽  
Photometric Variability ◽  
Central Engine ◽  
Relationship Of ◽  
The Relationship

Quasars are the choicest objects to define a quasi-inertial reference frame. At the same time, they are active galactic nuclei powered by a massive black hole. As the astrometric precision of ground-based optical observations approaches the limit set by the forthcoming GAIA mission, astrometric stability can be investigated. Though the optical emission from the core region usually exceeds the other components by a factor of a hundred, the variability of those components must surely imply some measure of variability of the astrometric baricenter. Whether this is confirmed or not, it puts important constraints on the relationship of the quasar's central engine to the surrounding distribution of matter. To investigate the correlation between long-term optical variability and what is dubbed as the “random walk” of the astrometric center, a program is being pursued at the WFI/ESO 2.2m. The sample was selected from quasars known to undergo large-amplitude and long-term optical variations (Smith et al. 1993; Teerikorpi 2000). The observations are typically made every two months. The treatment is differential, comparing the quasar position and brightness against a sample of selected stars for which the average relative distances and magnitudes remain constant. The provisional results for four objects bring strong support to the hypothesis of a relationship between astrometric and photometric variability. A full account is provided by Andrei et al. (2009).

scholarly journals BINARY CENTRAL STARS OF PLANETARY NEBULAE DISCOVERED THROUGH PHOTOMETRIC VARIABILITY. IV. THE CENTRAL STARS OF HaTr 4 AND Hf 2-2

2016 ◽  
Vol 152 (2) ◽  
pp. 34 ◽  
Author(s):  
Todd C. Hillwig ◽  
Howard E. Bond ◽  
David J. Frew ◽  
S. C. Schaub ◽  
Eva H. L. Bodman
Keyword(s):  
Planetary Nebulae ◽  
Photometric Variability ◽  
Central Stars
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