Search Publications
Multiwavelength Observations by XSM, Hinode, and SDO of an Active Region. Chemical Abundances and Temperatures
Mason, H. E.; Del Zanna, G.; Janardhan, P. +7 more
We have reviewed the first year of observations of the Solar X-ray Monitor (XSM) on board Chandrayaan-2 and the available multiwavelength observations to complement the XSM data, focusing on the Solar Dynamics Observatory AIA and Hinode XRT and EIS observations. XSM has provided disk-integrated solar spectra in the 1-15 keV energy range, observing…
Variations in Vertical CO/CO2 Profiles in the Martian Mesosphere and Lower Thermosphere Measured by the ExoMars TGO/NOMAD: Implications of Variations in Eddy Diffusion Coefficient
Vandaele, Ann Carine; Modak, Ashimananda; Brines, Adrian +19 more
Using the Nadir and Occultation for MArs Discovery instrument aboard Trace Gas Orbiter, we derived the CO/CO2 profiles between 75 and 105 km altitude with the equivalent width technique. The derived CO/CO2 profiles showed significant seasonal variations in the southern hemisphere with decreases near perihelion and increases n…
System parameters of three short-period cataclysmic variable stars
Dhillon, V. S.; Breedt, E.; Marsh, T. R. +9 more
Using photometric ULTRACAM observations of three new short-period cataclysmic variables (CVs), we model the primary eclipse light curves to extract the orbital separation, masses, and radii of their component stars. We find donor masses of $0.060\pm 0.008\, {\rm M_\odot }$, $0.042\pm 0.001\, {\rm M_\odot }$, and $0.042\pm 0.004\, {\rm M_\odot }$, …
A Generative Model for Quasar Spectra
Hogg, David W.; Foreman-Mackey, Daniel; Schindler, Jan-Torge +3 more
We build a multi-output generative model for quasar spectra and the properties of their black hole engines, based on a Gaussian process latent-variable model. This model treats every quasar as a vector of latent properties such that the spectrum and all physical properties of the quasar are associated with non-linear functions of those latent para…
K2-79b and K2-222b: Mass Measurements of Two Small Exoplanets with Periods beyond 10 days that Overlap with Periodic Magnetic Activity Signals
Vanderburg, Andrew; López-Morales, Mercedes; Bieryla, Allyson +28 more
We present mass and radius measurements of K2-79b and K2-222b, two transiting exoplanets orbiting active G-type stars observed with HARPS-N and K2. Their respective 10.99 day and 15.39 day orbital periods fall near periods of signals induced by stellar magnetic activity. The two signals might therefore interfere and lead to an inaccurate estimate …
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS - IV. Discovery of two new GW Vir stars: TIC 0403800675 and TIC 1989122424
Kepler, S. O.; Córsico, Alejandro H.; Uzundag, Murat +4 more
We present two new GW Vir-type pulsating white dwarf stars, TIC 0403800675 (WD J115727.68-280349.64) and TIC 1989122424 (WD J211738.38-552801.18) discovered in the Transiting Exoplanet Survey Satellite (TESS) photometric data. For both stars, the TESS light curves reveal the presence of oscillations with periods in a narrow range between 400 and 4…
Fast time optical variability in Be/X-ray binaries. Pulsation and rotation
Reig, P.; Fabregat, J.
Context. Classical Be stars, regardless of spectral subtype, display multi-periodic light modulations in the frequency range 0.1-12 c d−1 when observed with a high cadence and a long duration. This behavior is attributed to non-radial pulsations and/or the rotation of the Be star. A similar study on the optical counterparts to Be/X-ray …
Confirmation of the Long-period Planet Orbiting Gliese 411 and the Detection of a New Planet Candidate
Rosenthal, Lee J.; Howard, Andrew W.; Petigura, Erik A. +4 more
We perform a detailed characterization of the planetary system orbiting the bright, nearby M dwarf Gliese 411 using radial velocities gathered by APF, HIRES, SOPHIE, and CARMENES. We confirm the presence of a signal with a period near 2900 days that has been disputed as either a planet or a long-period stellar magnetic cycle. An analysis of activi…
The µ Arae Planetary System: Radial Velocities and Astrometry
McArthur, B. E.; Benedict, G. F.; Nelan, E. P. +4 more
With Hubble Space Telescope Fine Guidance Sensor astrometry and published and previously unpublished radial velocity measures, we explore the exoplanetary system µ Arae. Our modeling of the radial velocities results in improved orbital elements for the four previously known components. Our astrometry contains no evidence for any known compan…
A large catalogue of molecular clouds in the Southern sky
Chen, B. -Q.; Liu, X. -W.; Guo, H. -L.
We present a large catalogue of molecular clouds with accurate distance estimates in the Southern sky. Based on the three-dimensional dust extinction map and the best-fitting extinction and distance information of over 17 million stars presented in Guo et al. (2021, ApJ, 906, 47), we have identified 250 dust/molecular clouds in the Southern sky us…