Search Publications

ExoMars TGO/NOMAD-UVIS Vertical Profiles of Ozone: 2. The High-Altitude Layers of Atmospheric Ozone
DOI: 10.1029/2021JE006834 Bibcode: 2021JGRE..12606834K

Thomas, Ian; Daerden, Frank; Ristic, Bojan +12 more

Solar occultations performed by the Nadir and Occultation for MArs Discovery (NOMAD) ultraviolet and visible spectrometer (UVIS) onboard the ExoMars Trace Gas Orbiter (TGO) have provided a comprehensive mapping of atmospheric ozone density. The observations here extend over a full Mars year (MY) between April 21, 2018 at the beginning of the TGO s…

2021 Journal of Geophysical Research (Planets)
ExoMars-16 17
EPIC 228782059: Asteroseismology of What Could Be the Coolest Pulsating Helium-atmosphere White Dwarf (DBV) Known
DOI: 10.3847/1538-4357/ac22fd Bibcode: 2021ApJ...922....2D

Hermes, J. J.; Fu, J. -N.; Vanderbosch, Zachary P. +5 more

We present analysis of a new pulsating helium-atmosphere (DB) white dwarf, EPIC 228782059, discovered from 55.1 days of K2 photometry. The long-duration, high-quality light curves reveal 11 independent dipole and quadruple modes, from which we derive a rotational period of 34.1 ± 0.4 hr for the star. An optimal model is obtained from a series of g…

2021 The Astrophysical Journal
Gaia 17
X-ray variability of the HMXB Cen X-3: evidence for inhomogeneous accretion flows
DOI: 10.1093/mnras/staa3953 Bibcode: 2021MNRAS.501.5892S

Torrejón, J. M.; Postnov, K.; Oskinova, L. +3 more

Cen X-3 is a compact high-mass X-ray binary likely powered by Roche lobe overflow. We present a phase-resolved X-ray spectral and timing analysis of two pointed XMM-Newton observations. The first one took place during a normal state of the source, when it has a luminosity LX ∼ 1036 erg s-1. This observation covered…

2021 Monthly Notices of the Royal Astronomical Society
XMM-Newton 17
Solar energetic particle heavy ion properties in the widespread event of 2020 November 29
DOI: 10.1051/0004-6361/202141310 Bibcode: 2021A&A...656L..12M

Kulkarni, S. R.; Mitchell, D. G.; McComas, D. J. +57 more

Context. Following a multi-year minimum of solar activity, a solar energetic particle event on 2020 Nov. 29 was observed by multiple spacecraft covering a wide range of solar longitudes including ACE, the Solar Terrestrial Relations Observatory-A, and the recently launched Parker Solar Probe and Solar Orbiter.
Aims: Multi-point observations o…

2021 Astronomy and Astrophysics
SolarOrbiter 17
Weighing the Galactic disk in sub-regions of the solar neighbourhood using Gaia DR2
DOI: 10.1051/0004-6361/202039852 Bibcode: 2021A&A...646A..67W

Monari, G.; de Salas, P. F.; Widmark, A.


Aims: We infer the gravitational potential of the Galactic disk by analysing the phase-space densities of 120 stellar samples in 40 spatially separate sub-regions of the solar neighbourhood, using Gaia's second data release (DR2), in order to quantify spatially dependent systematic effects that bias this type of measurement.
Methods: The…

2021 Astronomy and Astrophysics
Gaia 17
Giant Outer Transiting Exoplanet Mass (GOT 'EM) Survey. II. Discovery of a Failed Hot Jupiter on a 2.7 Yr, Highly Eccentric Orbit
DOI: 10.3847/1538-3881/ac134b Bibcode: 2021AJ....162..154D

Esposito, Thomas M.; Kane, Stephen R.; Rosenthal, Lee J. +13 more

Radial velocity (RV) surveys have discovered giant exoplanets on au-scale orbits with a broad distribution of eccentricities. Those with the most eccentric orbits are valuable laboratories for testing theories of high-eccentricity migration. However, few such exoplanets transit their host stars, thus removing the ability to apply constraints on fo…

2021 The Astronomical Journal
Gaia 17
Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy
DOI: 10.3847/2041-8213/abd413 Bibcode: 2021ApJ...907L..42H

Huang, Yang; Chang, Jiang; Zhang, Huawei +5 more

In this Letter, we report the discovery of an intriguing hypervelocity star (HVS; J1443+1453) candidate that is probably from the Sagittarius Dwarf Spheroidal galaxy (Sgr dSph). The star is an old and very metal-poor low-mass main-sequence turn-off star (age ∼14.0 Gyr and [Fe/H] = -2.23 dex) and has a total velocity of ${559.01}_{-87.40}^{+135.07}…

2021 The Astrophysical Journal
Gaia 17
High-frequency Wave Power Observed in the Solar Chromosphere with IBIS and ALMA
DOI: 10.3847/1538-4357/ac1515 Bibcode: 2021ApJ...920..125M

Kowalski, Adam F.; Cranmer, Steven R.; Reardon, Kevin P. +3 more

We present observational constraints on the chromospheric heating contribution from acoustic waves with frequencies between 5 and 50 mHz. We use observations from the Dunn Solar Telescope in New Mexico, complemented with observations from the Atacama Large Millimeter Array collected on 2017 April 23. The properties of the power spectra of the vari…

2021 The Astrophysical Journal
IRIS 17
Discovery of 40.5 ks Hard X-Ray Pulse-phase Modulations from SGR 1900+14
DOI: 10.3847/1538-4357/ac28fd Bibcode: 2021ApJ...923...63M

Suzuki, H.; Enoto, T.; Makishima, K. +4 more

X-ray timing properties of the magnetar SGR 1900+14 were studied, using the data taken with Suzaku in 2009 and NuSTAR in 2016, for a time lapse of 114 and 242 ks, respectively. On both occasions, the object exhibited the characteristic two-component spectrum. The soft component, dominant in energies below ~5 keV, showed a regular pulsation, with a…

2021 The Astrophysical Journal
Suzaku 17
The Pulsating White Dwarf G117-B15A: Still the Most Stable Optical Clock Known
DOI: 10.3847/1538-4357/abc626 Bibcode: 2021ApJ...906....7K

Kepler, S. O.; Hermes, J. J.; Bell, Keaton J. +14 more

The pulsating hydrogen atmosphere white dwarf star G 117-B15A has been observed since 1974. Its main pulsation period at 215.19738823(63) s, observed in optical light curves, varies by only (5.12 ± 0.82) × 10-15 s s-1 and shows no glitches, as pulsars do. The observed rate of period change corresponds to a change of the pulsa…

2021 The Astrophysical Journal
Gaia 17