Search Publications
HATS-34b and HATS-46b: re-characterization using TESS and Gaia
Hartman, Joel D.; Louden, Emma M.
We present a revised characterization of the previously discovered transiting planet systems HATS-34 and HATS-46. We make use of the newly available space-based light curves from the NASA TESS mission and high-precision parallax and absolute photometry measurements from the ESA Gaia mission to determine the mass and radius of the planets and host …
The frequency by mass of Galactic carbon stars inferred from Gaia measurements of star cluster members
Worthey, G.; Pal, Tathagata
We investigate the frequency of occurrence of Galactic carbon stars as a function of progenitor mass using Gaia data. Small number statistics limit fidelity, but C-star frequency agrees with that observed in the Magellanic Clouds (MCs) down to m ≈ 1.67 M⊙. At m ≈ 1.38 M⊙, the frequency rises by a factor of three even though t…
τ9 Eri: a bright pulsating magnetic Bp star in a 5.95-d double-lined spectroscopic binary
Wade, G. A.; Pigulski, A.; Kochukhov, O. +2 more
τ9 Eri is a Bp star that was previously reported to be a single-lined spectroscopic binary. Using 17 ESPaDOnS spectropolarimetric (Stokes V) observations, we identified the weak spectral lines of the secondary component and detected a strong magnetic field in the primary. We performed orbital analysis of the radial velocities of both co…
A study of the long-term activity of five intermediate polars with accretion discs
Šimon, Vojtěch
Intermediate polars (IPs) are cataclysmic variables with mildly magnetized white dwarfs (WDs). This analysis of the long-term optical activity of five examples of IPs with accretion discs used data from the Catalina Real-time Transient Survey, Digital Access to a Sky Century @ Harvard (DASCH) and the American Association of Variable Star Observers…
Towards realistic estimates of solar global oscillation mode-coupling measurement noise
Woodard, M. F.
Time series of the medium-l spherical-harmonic decomposition of SOHO/MDI Doppler images were used to investigate the noise of solar-oscillation mode-coupling measurements and to reveal the coupling signatures of global-scale Rossby-waves and magnetic activity. A theoretical model of mode-coupling noise was developed starting from the assumption th…
Unveiling the nature of clusters in the Cygnus region. I. The embedded cluster DB2001-22
Molina Lera, J. A.; Baume, G.; Gamen, R. +2 more
The Cygnus region harbours a vast diversity of rich stellar complexes. Hence, it is ideal for studying recently formed stellar clusters, and investigate how the feedback effect and radiation emitted by its massive stars modifies the interstellar medium giving place to induced star forming processes. This is the case of the small and poorly studied…
A thermophysical and dynamical study of the Hildas, (1162) Larissa, and (1911) Schubart
Marshall, J. P.; Müller, T. G.; Drass, H. +3 more
The Hilda asteroids are among the least studied populations in the asteroid belt, despite their potential importance as markers of Jupiter's migration in the early Solar system. We present new mid-infrared observations of two notable Hildas, (1162) Larissa, and (1911) Schubart, obtained using the Faint Object infraRed CAmera for the SOFIA Telescop…
Study of central intensity ratio of early-type galaxies from low-density environment
Ravikumar, C. D.; Sruthi, K.
We present correlations involving central intensity ratio (CIR) of 52 early-type galaxies, including 24 ellipticals and 28 lenticulars, selected from low-density environment in the nearby (<30 Mpc) universe. CIR is found to be negatively and significantly correlated with the mass of the central supermassive black hole, central velocity dispersi…
Asteroseismology of SZ Lyn using multiband high time resolution photometry from ground and space
Ganesh, S.; Handler, G.; Joshi, Santosh +4 more
We report the analysis of high temporal resolution ground- and space-based photometric observations of SZ Lyncis, a binary star one of whose components is a high amplitude δ Scuti. UBVR photometric observations were obtained from Mt. Abu Infrared Observatory and Fairborn Observatory; archival observations from the WASP project were also included. …
Physical conditions and redshift evolution of optically thin C III>absorbers: low-z sample
Pradhan, Ananta C.; Mohapatra, Abhisek; Srianand, R.
We present a detailed analysis of 99 optically thin C III absorption systems at redshift 0.2 ≤ z ≤ 0.9 associated with neutral hydrogen column densities in the range 15 ≤ log $N({\rm{H\,{\small I}}})$ (cm-2) ≤ 16.2. Using photoionization models, we infer the number density (nH), C-abundance ([C/H]), and line-of-sight thicknes…