Search Publications
Spectroscopic and Photometric Study of the S-type Mira V667 Cassiopeiae and the Carbon Star OR Cephei
Boyd, D.
We report on spectroscopic and photometric observations of the S-type Mira V667 Cas and the carbon star Mira OR Cep recorded during one pulsation cycle of each star in 2022. Spectra are calibrated in absolute flux using concurrent photometry. We present measurements of V and Ic magnitudes and V-Ic color index, classify spectra in the revised MK sy…
Photometric Distance of the RR Lyrae Star SU Draconis using Period-Luminosity-Metallicity Relationships
Davis, J.; Baltich, B.; Siaw, K. +2 more
The distance to the RR Lyrae Star SU Draconis was estimated via photometric analysis using period-luminosity-metallicity equations from Cáceres and Catelan, as well as Garofalo's luminosity-metallicity equation. Exposures were taken in the B, V, i, and z bands over a two-week period (65 exposures per band). Photometry files from the cadence were a…
Investigation of the M13 Globular Cluster: Characteristics and Pulsation Periods of Its RR Lyrae Stars V8, V31, and V54
Wang, J.; Lee, K.; Tock, K. +2 more
Images of the Messier 13 (M13/NGC 6205) globular cluster were requested from the Las Cumbres Global Observatory's 40-centimeter telescope to investigate the chemical composition and characteristics of the cluster along with three of its RR Lyrae variable stars. Gaia Data Release 3 data were used to fit an isochrone by varying parameters such as di…
X-ray Luminosity Versus Orbital Period of AM CVn Systems
Maccarone, T. J.; Begari, T.
AM CVn systems are a rare type of cataclysmic variable star consisting of a white dwarf accreting material from a low-mass, hydrogen-poor donor star. These helium-rich systems usually have orbital periods that are less than 65 minutes and are predicted to be sources of gravitational waves. We have analyzed the catalogued x-ray data from the Chandr…
Markov Chain Monte Carlo Optimization applied to Dysonís Visual Double Stars
Budding, E.; Banks, T.; Si, I. S. X. +1 more
Estimates of orbital parameters were made using a Bayesian optimization technique on astrometric data for 25 visual binary systems catalogued a century ago by the ninth Astronomer Royal, Sir Frank Dyson. An advantage of this method is that it provides reliable, unbiased uncertainty estimates for the optimized parameters. Reasonable agreement is fo…
Spectroscopic and Photometric Study of the Eclipsing Binary Star sigma Aquilae
Quadri, U.; Strabla, L.; Franco, L.
We report on spectroscopic and photometric observations of the eclipsing binary star sigma Aquilae (44 Aql). Archival TESS and Hipparcos data are used to confirm the orbital period of 1.95028 ± 0.00002 days, consistent with previous measurements. Doppler shifts of the He I line at 4922 Angstroms from high-resolution spectroscopic data were used to…
Infrared Photometric Distance to WZ Hya
Allen, M. L.; Ritterby, C.
A distance to the RR Lyrae star WZ Hya was determined to test how well period-luminosity-metallicity (PLZ) relations agree with current parallax measurements from Gaia. We obtained 120 photometric observations in the B, V, ip, and zs filters from 16 February to 28 May 2022. Fluxes were extracted using six-aperture photometry methods. The period fo…
Photometric Distance to the RR Lyrae Star SW Andromedae Using Period-Luminosity-Metallicity Relationships
Payne, E.; Dow, T.; Bergstedt, J. +4 more
Cáceres and Catelans' period-luminosity-metallicity equations give us a way to measure the photometric distance to RR Lyrae stars using absolute magnitude equations that rely on the specific photometric filter (V, i, and z), the period, and the metallicity. Over a period of two weeks, 76 images of the RR Lyr Star SW Andromedae were taken in the B,…
Distance Determination of RR Lyrae Stars AE Leo, AT Vir, and HY Com
Soper, C.; Tenenbaum, C.; Lounsbery, A. +2 more
We present the results of our observations and analyses of three RR Lyrae variable stars: AT Vir, HY Com, and AE Leo, in order to test period-luminosity relationships derived from stellar models. We have measured the periods of these stars to be 0.52359, 0.44898, and 0.63021 days, respectively, closely matching previous work. Period-Luminosity-Met…
BViz Photometry of the RR Lyrae Star RU Ceti
Fickle, J.; Allen, M. L.
The RR Lyrae star RU Cet was observed between October 26 and November 23, 2020. The observations were taken in the B, V, ip, and zs filters, with the telescope images being analyzed using various aperture photometry methods. The period of variation for RU Cet was found to be 0.585 ± 0.020 day. Theoretical period-luminosity-metallicity relations in…