Search Publications
The Stars Kepler Missed: Investigating the Kepler Target Selection Function Using Gaia DR2
Huber, Daniel; Berger, Travis A.; Wolniewicz, Linnea M.
The Kepler Mission revolutionized exoplanet science and stellar astrophysics by obtaining highly precise photometry of over 200,000 stars over 4 yr. A critical piece of information to exploit Kepler data is its selection function, since all targets had to be selected from a sample of half a million stars on the Kepler CCDs using limited informatio…
First Phase Space Portrait of a Hierarchical Stellar Structure in the Milky Way
Dalessandro, Emanuele; Saracino, S.; Bellazzini, M. +10 more
We present the first detailed observational picture of a possible ongoing massive cluster hierarchical assembly in the Galactic disk as revealed by the analysis of the stellar full phase space (3D positions and kinematics and spectro-photometric properties) of an extended area (6° diameter) surrounding the well-known h and χ Persei double stellar …
First near-relativistic solar electron events observed by EPD onboard Solar Orbiter
Fedorov, A.; Kulkarni, S. R.; Lario, D. +61 more
Context. Solar Orbiter, launched in February 2020, started its cruise phase in June 2020, in coincidence with its first perihelion at 0.51 au from the Sun. The in situ instruments onboard, including the Energetic Particle Detector (EPD), operate continuously during the cruise phase enabling the observation of solar energetic particles.
Aims: …
GW190814 follow-up with the optical telescope MeerLICHT
Vreeswijk, P. M.; Groot, P. J.; Bloemen, S. +8 more
Context. The Advanced LIGO and Virgo gravitational wave observatories detected a signal on 2019 August 14 during their third observing run, named GW190814. A large number of electromagnetic facilities conducted follow-up campaigns in the search for a possible counterpart to the gravitational wave event, which was made especially promising given th…
The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars
France, Kevin; Youngblood, Allison; Pineda, J. Sebastian
Accurate stellar properties are essential for precise stellar astrophysics and exoplanetary science. In the M-dwarf regime, much effort has gone into defining empirical relations that can use readily accessible observables to assess physical stellar properties. Often, these relations for the quantity of interest are cast as a nonlinear function of…
Inspecting the Cepheid parallax of pulsation using Gaia EDR3 parallaxes. Projection factor and period-luminosity and period-radius relations
Kervella, P.; Trahin, B.; Mérand, A. +5 more
Context. As primary anchors of the distance scale, Cepheid stars play a crucial role in our understanding of the distance scale of the Universe because of their period-luminosity relation. Determining precise and consistent parameters (radius, temperature, color excess, and projection factor) of Cepheid pulsating stars is therefore very important.…
GD 424 - a helium-atmosphere white dwarf with a large amount of trace hydrogen in the process of digesting a rocky planetesimal
Redfield, Seth; Gänsicke, Boris T.; Rodríguez-Gil, Pablo +5 more
The photospheric metal pollution of white dwarfs is now well established as the signature of the accretion of planetary debris. However, the origin of the trace hydrogen detected in many white dwarfs with helium atmospheres is still debated. Here, we report the analysis of GD 424: a metal-polluted, helium-atmosphere white dwarf with a large amount…
Understanding Polarized Dust Emission from ρ Ophiuchi A in Light of Grain Alignment and Disruption by Radiative Torques
Soam, Archana; Hoang, Thiem; Lee, Hyeseung +5 more
The alignment of dust grains with the ambient magnetic field produces polarization of starlight as well as thermal dust emission. Using the archival SOFIA/HAWC+ polarimetric data observed toward the ρ Ophiuchus (Oph) A cloud hosted by a B star at 89 and 154 µm, we find that the fractional polarization of thermal dust emission first increases…
Time and Charge-sign Dependence of the Heliospheric Modulation of Cosmic Rays
Potgieter, M. S.; Aslam, O. P. M.; Bisschoff, D. +4 more
Simultaneous and continuous observations of galactic cosmic-ray electrons (e-) and positrons (e+) from the PAMELA and AMS02 space experiments are most suitable for numerical modeling studies of the heliospheric modulation of these particles below 50 GeV. A well-established comprehensive three-dimensional modulation model is a…
The Source of Leaking Ionizing Photons from Haro11: Clues from HST/COS Spectroscopy of Knots A, B, and C
Cannon, John M.; Hayes, Matthew; Östlin, Göran +15 more
Understanding the escape of ionizing (Lyman continuum) photons from galaxies is vital for determining how galaxies contributed to reionization in the early universe. While directly detecting the Lyman continuum from high-redshift galaxies is impossible due to the intergalactic medium, low-redshift galaxies in principle offer this possibility but r…