Search Publications
Mutual Orbital Inclinations between Cold Jupiters and Inner Super-Earths
Winn, Joshua N.; Kawahara, Hajime; Masuda, Kento
Previous analyses of Doppler and Kepler data have found that Sun-like stars hosting “cold Jupiters” (giant planets with a ≳ 1 au) almost always host “inner super-Earths” (1-4 R ⊕, a ≲ 1 au). Here we attempt to determine the degree of alignment between the orbital planes of the cold Jupiters and the inner super-Earths. The key observatio…
The Gemini Planet Imager Exoplanet Survey: Dynamical Mass of the Exoplanet β Pictoris b from Combined Direct Imaging and Astrometry
Duchêne, Gaspard; Esposito, Thomas M.; Oppenheimer, Rebecca +51 more
We present new observations of the planet β Pictoris b from 2018 with the Gemini Planet Imager (GPI), the first GPI observations following conjunction. Based on these new measurements, we perform a joint orbit fit to the available relative astrometry from ground-based imaging, the Hipparcos Intermediate Astrometric Data (IAD), and the Gaia DR2 pos…
Common dynamo scaling in slowly rotating young and evolved stars
Spada, Federico; Lehtinen, Jyri J.; Käpylä, Maarit J. +2 more
One interpretation of the activity and magnetism of late-type stars is that these both intensify with decreasing Rossby number up to a saturation level1-3, suggesting that stellar dynamos depend on both rotation and convective turbulence4. Some studies have claimed, however, that rotation alone suffices to parametrize this sc…
Spectroscopic confirmation of a mature galaxy cluster at a redshift of 2
Brammer, G.; Stanford, S. A.; Allen, S. W. +6 more
Galaxy clusters are the most massive virialized structures in the Universe and are formed through the gravitational accretion of matter over cosmic time1. The discovery2 of an evolved galaxy cluster at redshift z = 2, corresponding to a look-back time of 10.4 billion years, provides an opportunity to study its properties. The…
Active red giants: Close binaries versus single rapid rotators
Gaulme, Patrick; Vrard, Mathieu; McKeever, Jean +7 more
Oscillating red-giant stars have provided a wealth of asteroseismic information regarding their interiors and evolutionary states, which enables detailed studies of the Milky Way. The objective of this work is to determine what fraction of red-giant stars shows photometric rotational modulation, and understand its origin. One of the underlying que…
IRIS Observations of Short-term Variability in Moss Associated with Transient Hot Coronal Loops
Polito, Vanessa; Testa, Paola; De Pontieu, Bart
We observed rapid variability (≲60 s) at the footpoints of transient, hot (∼8-10 MK) coronal loops in active region cores, with the Interface Region Imaging Spectrograph (IRIS). The high spatial (∼0"33) and temporal (≲5-10 s) resolution of IRIS is often crucial for the detection of this variability. We show how, in combination with 1D RADYN loop m…
The final SDSS-IV/SPIDERS X-ray point source spectroscopic catalogue
Georgakakis, A.; Salvato, M.; Buchner, J. +15 more
Aims: We look to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV programme aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources.
Methods: We describe the SPIDERS X-ray Point Source Spectroscopi…
Case study of multi-temperature coronal jets for emerging flux MHD models
Nóbrega-Siverio, Daniel; Aulanier, Guillaume; Schmieder, Brigitte +4 more
Context. Hot coronal jets are a basic observed feature of the solar atmosphere whose physical origin is still actively debated.
Aims: We study six recurrent jets that occurred in active region NOAA 12644 on April 4, 2017. They are observed in all the hot filters of AIA as well as cool surges in IRIS slit-jaw high spatial and temporal resoluti…
A nearby recent supernova that ejected the runaway star ζ Oph, the pulsar PSR B1706-16, and 60Fe found on Earth
Neuhäuser, R.; Hambaryan, V. V.; Gießler, F.
The detection of ∼1.5-3.2 Myr old 60Fe on Earth indicates recent nearby core-collapse supernovae. For supernovae in multiple stars, the primary stars may become neutron stars, while former companions may become unbound and become runaway stars. We wrote software for tracing back the space motion of runaway and neutron stars to young ass…
TOI-1235 b: A Keystone Super-Earth for Testing Radius Valley Emergence Models around Early M Dwarfs
López-Morales, Mercedes; Latham, David W.; Esquerdo, Gilbert A. +85 more
Small planets on close-in orbits tend to exhibit envelope mass fractions of either effectively zero or up to a few percent depending on their size and orbital period. Models of thermally driven atmospheric mass loss and of terrestrial planet formation in a gas-poor environment make distinct predictions regarding the location of this rocky/nonrocky…