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CCD Photometry, Light Curve Modeling, and Period Study of the Overcontact Binary Systems NSVS 7245866 and V685 Pegasi
Alton, K. B.
Precise time-series multi-color (B, V, and Ic) light curve data were acquired at UnderOak Observatory (UO) from NSVS 7245866 (2017) and V685 Peg (2016). Prior to this investigation only monochromatic CCD data for both variables were available from automated surveys which employ sparse sampling strategies. Each target produced new times-of-minimum …
Studies of Exoplanets with Candidate TOI 717.01 and Confirmed HAT-P-3b (Abstract)
Nair, S.; Tock, K.; Koodli, K. +1 more
(Abstract only) Images of the exoplanets TOI 717.01, Qatar-8 b, and HAT-P-3 b were requested in the w-filter from the Las Cumbres Observatory 0.4-meter telescopes. Of these requests, images were taken of TOI 717.01 and HAT-P-3 b and were reduced using the EXOplanet Transit Interpretation Code (EXOTIC) software, as well as 6 photometric algorithms …
U, B, V, Rc, Ic Photometric Observations of the Dwarf Nova DX Andromedae During the Years 2018-2019
Ciprini, S.; Spogli, C.; Rocchi, G. +1 more
In this paper we present U, B,V, Rc, Ic photometric observations of the dwarf nova DX Andromedae made in the years 2018-2019 at the private Rocchi observatory located in Spello (Umbria). We observed the variable for 86 nights in B, V, Rc, Ic photometric filters. We detected an outburst of this dwarf nova. We summarize the significant variations in…
A Photometric Study of the Contact Binary GR Piscium
Michaels, E. J.
High-quality CCD photometric light curves of the eclipsing binary GR Psc are presented. The new multicolor light curves display total eclipses which were analyzed using the Wilson-Devinney program. The light curve solution describes the system as a contact configuration with a mass ratio of M2 / M1 = 0.431, a fill-out of f = 47%, and a small tempe…
V725 Sagittarii: Unique, Important, Neglected
Percy, J. R.
During the last century, V725 Sgr gradually changed from a 12-day Cepheid to an 85-day yellow semiregular giant. This paper presents wavelet analysis of AAVSO visual observations from 1982 to 2020, and Fourier analysis of ASAS-SN observations from 2016 to 2018. The results confirm that the previously-identified pulsation period has increased from …
The Reclassification of NSV 1586 from a Suspected Cepheid Star to a UG Class System
Hills, K.; Brincat, S. M.; Galdies, C. +1 more
On 2018 August 9, a contribution to the VSNET mailing list suggested that due to certain photometric attributes, NSV 1586 could possibly belong to the Dwarf Nova (DN) class. Hence, the initial classification of this star as a Cepheid variable star was put into question. This prompted the authors to investigate NSV 1586 in detail. The data obtained…
Observation of Gaia (DR2) Red and White Dwarf Binary Stars in the Solar Neighborhood (Abstract)
Wasson, R.
(Abstract only) The Gaia satellite combines astrometric, parallax, photometric, and spectroscopic measurements of stellar propertiesówith greater accuracy than ever before. In 2018 Gaia Data Release 2 (DR2) made preliminary but consistent data available for an extraordinary number of stars: 1.3 Billion!
SZ Sculptoris: Light Curve Analyses and Period Study of the Totally Eclipsing, Galactic South Pole, Solar-Type Binary
Hill, R.; Van Hamme, W.; Samec, R. G.
We report here on the first precision BVRI observations, analysis and period study of SZ Sculptoris (GSC 6990-0597), a solar type (T ~ 5040 K), shallow contact, eclipsing binary. It was observed on 2019 October 05 and 2019 November 05 and 07 in remote mode with the Cerro Tololo InterAmerican Observatory 0.6-m SARA South reflector by R. Samec and R…
HD 121620: A Previously Unreported Variable Star with Unusual Properties
Axelsen, R. A.
During a study of the delta Scuti star V1393 Centauri by digital single lens reflex photometry, it was found that two of the chosen comparison stars were variable. This paper reports the subsequent investigation of one of them, HD 121620, which revealed irregular light variations of 0.8 magnitude in V within a time frame of approximately 24 hours.…
Analysis of HAT-P-23 b, Qatar-1 b, WASP-2 b, and WASP-33 b with an Optimized EXOplanet Transit Interpretation Code (Abstract)
Nair, S.; Varghese, J.; Tock, K. +1 more
(Abstract only) The ability for citizen scientists to analyze image data and search for exoplanets using images from small telescopes has the potential to greatly accelerate the search for exoplanets. Recent work on the Exoplanet Transit Interpretation Code (EXOTIC) enables the generation of high-quality light curves of exoplanet transits given su…