Search Publications
Constraining the assembly time of the stellar haloes of nearby Milky Way-mass galaxies through AGB populations
Bell, Eric F.; Holwerda, Benne W.; Monachesi, Antonela +5 more
The star formation histories (SFHs) of galactic stellar haloes offer crucial insights into the merger history of the galaxy and the effects of those mergers on their hosts. Such measurements have revealed that while the Milky Way's most important merger was 8-10 Gyr ago, M31's largest merger was more recent, within the last few Gyr. Unfortunately,…
Catching a nova X-ray/UV flash in the visible? Early spectroscopy of the very slow Nova Velorum 2022 (Gaia22alz)
Mukai, K.; Sokoloski, J. L.; Mróz, P. +22 more
We present early spectral observations of the very slow Galactic nova Gaia22alz, over its gradual rise to peak brightness that lasted 180 d. During the first 50 d, when the nova was only 3-4 mag above its normal brightness, the spectra showed narrow (FWHM ≈ 400 km s-1) emission lines of H Balmer, He I, He II, and C IV but no P Cygni abs…
Revisiting Orbital Evolution in HAT-P-2 b and Confirmation of HAT-P-2 c
Fulton, Benjamin J.; Howard, Andrew W.; Winn, Joshua N. +5 more
One possible formation mechanism for Hot Jupiters is that high-eccentricity gas giants experience tidal interactions with their host star that cause them to lose orbital energy and migrate inwards. We study these types of tidal interactions in an eccentric Hot Jupiter called HAT-P-2 b, which is a system where a long-period companion has been sugge…
Modeling CME encounters at Parker Solar Probe with OSPREI: Dependence on photospheric and coronal conditions
Al-Haddad, Nada; Riley, Pete; Palmerio, Erika +2 more
Context. Coronal mass ejections (CMEs) are eruptions of plasma from the Sun that travel through interplanetary space and may encounter Earth. CMEs often enclose a magnetic flux rope (MFR), the orientation of which largely determines the CMEs' geoeffectiveness. Current operational CME models do not model MFRs, but a number of research ones do, incl…
Origin of Quasi-periodic Pulsation at the Base of a Kink-unstable Jet
Srivastava, A. K.; Kayshap, Pradeep; Rajaguru, S. P. +3 more
We studied a blowout jet that occurred at the west limb of the Sun on 2014 August 29 using high-resolution imaging/spectroscopic observations provided by the Solar Dynamics Observatory/Atmospheric Imaging Assembly and the Interface Region Imaging Spectrograph. An inverse γ-shaped flux rope appeared before the jet-morphological indication of the on…
Three Ultra-short-period Contact Eclipsing Binary Systems Mined from Massive Astronomical Surveys
Ferreira Lopes, C. E.; Drake, Andrew J.; Catelan, Márcio +3 more
We present the photometric analysis of three ultra-short-period total eclipsing binaries in contact configuration, CRTS_J172718.0+431624, OGLE-BLG-ECL-000104, and OGLE-BLG-ECL-000012, mined from massive astronomical surveys. Using the available archival light curves (LCs) from Vista Variables in the Vía Láctea (VVV), Optical Gravitational Lensing …
Heliospheric 3-D MHD ENLIL simulations of multi-CME and multi-spacecraft events
Odstrcil, Dusan
Interpreting multi-spacecraft heliospheric observations of the evolving solar wind (SW) streams with propagating and interacting coronal mass ejections (CMEs) is challenging. Numerical simulations can provide global context and suggest what may and may not be observed. The heliospheric three-dimensional (3D) magnetohydrodynamic (MHD) ENLIL model c…
A study of carbon-rich post-AGB stars in the Milky Way to understand the production of carbonaceous dust from evolved stars
Dell'Agli, F.; Tailo, M.; Ventura, P. +5 more
Context. Knowledge of the Gaia, DR3 parallaxes of Galactic post-asymptotic giant branch (AGB) stars makes it possible to exploit these objects as tracers of AGB evolution, nucleosynthesis, and dust production as well as to use them to shed new light on still poorly known physical processes experienced by AGB stars.
Aims: The goal of this stud…
TOI-2084 b and TOI-4184 b: Two new sub-Neptunes around M dwarf stars
Alonso, R.; Bouchy, F.; Queloz, D. +67 more
We present the discovery and validation of two TESS exoplanets orbiting nearby M dwarfs: TOI-2084 b, and TOI-4184b. We characterized the host stars by combining spectra from Shane/Kast and Magellan/FIRE, spectral energy distribution analysis, and stellar evolutionary models. In addition, we used Gemini-South/Zorro & -North/Alopeke high-resolut…
Green Bank Telescope Discovery of the Redback Binary Millisecond Pulsar PSR J0212+5321
Perez, Karen I.; Bogdanov, Slavko; Halpern, Jules P. +1 more
We report the discovery of a 2.11 ms binary millisecond pulsar during a targeted search of the redback optical candidate coincident with the γ-ray source 3FGL J0212.5+5320 using the Robert C. Byrd Green Bank Telescope (GBT) with the Breakthrough Listen backend at L band. Over a seven month period, five pointings were made near inferior conjunction…