English
Related papers

Related papers: A Note on the Variability of V538 Cassiopeiae

200 papers

This work presents the first long-term photometric variability survey of the intermediate-age open cluster NGC 559. Time-series V band photometric observations on 40 nights taken over more than three years with three different telescopes…

Solar and Stellar Astrophysics · Physics 2020-09-30 Yogesh C. Joshi , Ancy Anna John , Jayanand Maurya , Alaxendra Panchal , Brijesh Kumar , Santosh Joshi

We present time-series photometry of nine cataclysmic variables: EI UMa, V844Her, V751 Cyg, V516 Cyg, GZ Cnc, TY Psc, V1315 Aql, ASAS J002511+1217.12, V1315 Aql and LN UMa. The observations were conducted at various observatories, covering…

Astrophysics · Physics 2008-06-10 C. Papadaki , H. M. J. Boffin , V. Stanishev , P. Boumis , S. Akras , C. Sterken

Observations from the Heliospheric Imagers (HI-1) on both the STEREO spacecraft have been analysed to search for very long period large amplitude stellar variability, finding 6 new candidates. A total of 85 objects, mostly previously known…

Solar and Stellar Astrophysics · Physics 2015-06-05 K. T. Wraight , D. Bewsher , Glenn J. White , W. Nowotny , A. J. Norton , C. Paladini

We present the first CCD photometric observations of the northern open cluster NGC 2126. Data were taken on eight nights in February and December 2002 with a total time span of ~57 hours. Almost 1000 individual V-band frames were examined…

Astrophysics · Physics 2009-03-09 A. Gaspar , L. L. Kiss , T. R. Bedding , A. Derekas , S. Kaspi , Cs. Kiss , K. Sarneczky , Gy. M. Szabo , M. Varadi

From optical R band data of the double quasar QSO 0957+561A,B, we made two new difference light curves (about 330 days of overlap between the time-shifted light curve for the A image and the magnitude-shifted light curve for the B image).…

We present photometric CCD observations of stars in four stellar trapezia ADS 15184, ADS 4728, ADS 2843, and ADS 16795. This study is performed on images obtained at the Observatorio Astron\'omico Nacional at San Pedro M\'artir (OAN), Baja…

Solar and Stellar Astrophysics · Physics 2024-03-04 A. Ruelas-Mayorga , L. J. Sánchez , A. Páez-Amador , O. Segura-Montero , A. Nigoche-Netro

Variability is a commonly observed property of classical Be stars (CBe) stars. In extreme cases, complete disappearance of the H{\alpha} emission line occurs, indicating a disc-less state in CBe stars. The disc-loss and reappearing phases…

We have searched for variable stars in deep V-band images of a field towards the Galactic plane in Carina. The images were taken with VIMOS instrument at ESO VLT during 4 contiguous nights in April 2005. We detected 348 variables among…

Solar and Stellar Astrophysics · Physics 2015-05-13 P. Pietrukowicz , D. Minniti , J. M. Fernandez , G. Pietrzynski , M. T. Ruiz , W. Gieren , R. F. Diaz , M. Zoccali , M. Hempel

Variability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well studied BL Lac through the whole electro-magnetic wavebands. In the present work, we show its optical R band photometric observations…

The observations with the SAO-RAS 6-m telescope in July-August 1998 show that the GRB970508 optical remnant has varied very little since November 1997. We can conclude that we observe a proper host galaxy without the GRB optical remnant.…

Astrophysics · Physics 2009-10-31 S. V. Zharikov , V. V. Sokolov

We present new BV CCD photometry, light curves, and ephemerides for 9 previously known, 29 newly detected RR Lyrae variables and one newly detected variable of an unknown type in the globular cluster M75. The photometry used for the…

Astrophysics · Physics 2009-11-07 T. M. Corwin , M. Catelan , H. A. Smith , J. Borissova , F. R. Ferraro , W. S. Raburn

Visual photometry, the estimation of stellar brightness by eye, continues to provide valuable data even in this highly-instrumented era. However, the eye-brain system functions differently from electronic sensors and its products can be…

Instrumentation and Methods for Astrophysics · Physics 2024-01-02 Alan B. Whiting

We present the first CCD variability study of the Draco dwarf spheroidal galaxy. The data were obtained with the FLWO 1.2 m telescope on 22 nights, over a period of 10 months, covering a 22 x 22 arcmin field centered at RA=17:19:57.5,…

Astrophysics · Physics 2008-11-26 A. Z. Bonanos , K. Z. Stanek , A. H. Szentgyorgyi , D. D. Sasselov , G. A. Bakos

In order to extend our previous studies of the unexplained phenomenon of cyclic amplitude variations in pulsating red giants, we have used the AAVSO time-series analysis package VSTAR to analyze long-term AAVSO visual observations of 50…

Solar and Stellar Astrophysics · Physics 2017-09-29 John R. Percy , Jennifer Laing

The Chinese Small Telescope ARray (CSTAR) carried out high-cadence time-series observations of 20.1 square degrees centered on the South Celestial Pole during the 2008, 2009 & 2010 winter seasons from Dome A in Antarctica. The…

This study shows that the carbon star CGCS 673 is a semi-regular (SR) variable star with a period of 135 d and an amplitude of 0.18 magnitudes in the V-band. The light curve obtained by this study correlates well with the SR classification…

Solar and Stellar Astrophysics · Physics 2020-12-02 Stephen M Brincat , Charles Galdies , Kevin Hills

We investigate small-scale light variations in V646 Pup occurring on different timescales with the aim to investigate whether this variability is similar to that observed in FU Ori. We observed V646 Pup at the SAAO and CTIO between 2013 and…

Solar and Stellar Astrophysics · Physics 2021-01-04 Michał Siwak , Waldemar Ogłoza , Jerzy Krzesiński

We present observations and analysis of the 2009 outburst of the unusual dwarf nova V630 Cas which is only the third recorded outburst of this star. The outburst lasted about 104 days, with the rise to maximum being slightly slower than the…

Solar and Stellar Astrophysics · Physics 2009-11-09 Jeremy Shears , Gary Poyner

We present the results of our optical (VRI) observations of the TeV blazar PG 1553+113 over eight nights in 2016 April. We monitored the blazar quasi-simultaneously in V and R bands each night and examined the light curves (LCs) for…

High Energy Astrophysical Phenomena · Physics 2019-03-29 Ashwani Pandey , Alok C. Gupta , Paul J. Wiita , S. N. Tiwari

As extensive ground-based observations and characterisation of different variable stars are of the utmost importance in preparing optimal input catalogues for space missions, our aim was to search for new variable stars in selected fields…