Search Publications
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,…