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Spectroscopic and Photometric Study of the Mira Stars SU Camelopardalis and RY Cephei
DOI: 10.48550/arXiv.2107.10061 Bibcode: 2021JAVSO..49..157B

Boyd, D.

Miras are fascinating stars. A kappa-mechanism in their atmosphere drives pulsations which produce changes in their photometric brightness, apparent spectral type, and effective temperature. These pulsations also drive the formation of Balmer emission lines in the spectrum. This behavior can be observed and investigated with small telescopes. We r…

2021 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 2
Discovery of Romanov V20, an Algol-Type Eclipsing Binary in the Constellation Centaurus, by Means of Data Mining
DOI: 10.48550/arXiv.2111.11086 Bibcode: 2021JAVSO..49..130R

Romanov, Filipp Dmitrievich

I report my discovery of the large-amplitude Algol-type eclipsing binary system which was initially added to the AAVSO International Variable Star Index (VSX) under the designation of Romanov V20. I describe selection criteria for searching for variability among other stars, the search of photometric data from several sky surveys, and my observati…

2021 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 1
Distances for the RR Lyrae Stars UU Ceti, UW Gruis, and W Tucanae
DOI: 10.48550/arXiv.2111.05286 Bibcode: 2021JAVSO..49..178P

Parker, R.; Banks, T.; Parker, L. +2 more

B, V, i, and z bandpass observations were collected in late 2020 for three RRab type stars: UU Ceti, UW Gruis, and W Tucanae. The period-luminosity (PL) relationships of Catalen, Pritzl, and Smith (2004, ApJSupp, 154) and Caceres and Catelan (2008, ApJSuppl, 179) were applied to derive distances. These were found to be in reasonable agreement with…

2021 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 1
Four New Variable Stars in the Field of KELT-16
Bibcode: 2021JAVSO..49...24B

Brossard, D. J.; Kaitchuck, R. H.

We present three new variable stars in the field around the star KELT-16, and new period estimates for four previously known contact binary systems in this field, ASASSN-V J205658.12+314215.9, ASASSN-V J205552.88+314615.9, ZTF J205733.78+314612.6, and ZTF J205627.42+315322.4. Due to the short periods of these three new variable stars, and the shap…

2021 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 0
High Cadence Millimagnitude Photometric Observation of V1112 Persei (Nova Per 2020)
DOI: 10.48550/arXiv.2107.10915 Bibcode: 2021JAVSO..49..151T

Thomas, N.; Ziegler, K.; Liu, P.

The private Lookout Observatory (LO) monitored the classical nova V1112 Persei on 37 nights spanning over 80 days, beginning shortly after its discovery by Seiji Ueda on 25 November 2020. Images were captured at a high cadence, with exposure lengths of initially less than 2 seconds and with some sessions lasting more than ten hours. The standard e…

2021 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 0
Photometric Determination of the Distance to the RR Lyrae Star YZ Capricorni
Bibcode: 2021JAVSO..49..247L

Lester, J.; Joignant, R.; Meier, M.

The RR Lyrae YZ Cap was observed using photometric methods to determine its pulsation period and distance. Light curves in the Bessell B and V and SDSS i' and z' filters were used to determine the period, which was found to be 0.274 ± 0.003 day. The distances calculated using a luminosity-metallicity (V filter) and period-luminosity-metallicity re…

2021 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 0
CCD Photometry, Light Curve Modeling, and Period Study of the Overcontact Binary Systems NSVS 7245866 and V685 Pegasi
Bibcode: 2020JAVSO..48...40A

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 …

2020 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 3
Studies of Exoplanets with Candidate TOI 717.01 and Confirmed HAT-P-3b (Abstract)
DOI: 10.48550/arXiv.2006.12658 Bibcode: 2020JAVSO..48R.265N

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 …

2020 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 2
U, B, V, Rc, Ic Photometric Observations of the Dwarf Nova DX Andromedae During the Years 2018-2019
Bibcode: 2020JAVSO..48..234S

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…

2020 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 2
A Photometric Study of the Contact Binary GR Piscium
Bibcode: 2020JAVSO..48..193M

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…

2020 Journal of the American Association of Variable Star Observers (JAAVSO)
Gaia 1