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Hyper-runaway and hypervelocity white dwarf candidates in Gaia Data Release 3: Possible remnants from Ia/Iax supernova explosions or dynamical encounters
DOI: 10.1093/mnras/stac3488 Bibcode: 2023MNRAS.518.6223I

Igoshev, Andrei P.; Hallakoun, Na'ama; Perets, Hagai

Type Ia and other peculiar supernovae (SNe) are thought to originate from the thermonuclear explosions of white dwarfs (WDs). Some of the proposed channels involve the ejection of a partly exploded WD (e.g. Iax SN remnant) or the companion of an exploding WD at extremely high velocities (>400 km s-1). Characterization of such hyper-r…

2023 Monthly Notices of the Royal Astronomical Society
Gaia 18
The GAPS Programme at TNG. XLII. A characterisation study of the multi-planet system around the 400 Myr-old star HD 63433 (TOI-1726)
DOI: 10.1051/0004-6361/202245391 Bibcode: 2023A&A...672A.126D

Baratella, M.; Mallonn, M.; Scandariato, G. +34 more

Context. The GAPS collaboration is carrying out a spectroscopic and photometric follow-up of a sample of young stars with planets (age ≲600 Myr) to characterise planetary systems at the early stages of their evolution.
Aims: For more than 2 yr, we monitored with the HARPS-N spectrograph the 400 Myr-old star HD 63433, which hosts two close-in …

2023 Astronomy and Astrophysics
Gaia 18
Gaia Data Release 3. The first Gaia catalogue of variable AGN
DOI: 10.1051/0004-6361/202244035 Bibcode: 2023A&A...674A..24C

Gavras, Panagiotis; Audard, Marc; Clementini, Gisella +15 more

Context. One of the novelties of Gaia data release 3 (DR3) with respect to the previous data releases is the publication of the multiband light curves for about 1 million active galactic nuclei (AGN) and of the values of some parameters characterising their variability properties.
Aims: The goal of this work is the creation of a catalogue of …

2023 Astronomy and Astrophysics
Gaia 18
Validating AU Microscopii d with Transit Timing Variations
DOI: 10.3847/1538-3881/acfda8 Bibcode: 2023AJ....166..232W

Barclay, Thomas; Triaud, Amaury H. M. J.; Dreizler, Stefan +31 more

AU Mic is a young (22 Myr), nearby exoplanetary system that exhibits excess transit timing variations (TTVs) that cannot be accounted for by the two known transiting planets nor stellar activity. We present the statistical "validation" of the tentative planet AU Mic d (even though there are examples of "confirmed" planets with ambiguous orbital pe…

2023 The Astronomical Journal
Gaia 18
Outflowing Helium from a Mature Mini-Neptune
DOI: 10.3847/2041-8213/aced51 Bibcode: 2023ApJ...953L..25Z

Knutson, Heather A.; Dai, Fei; Bean, Jacob L. +2 more

We announce the detection of escaping helium from TOI 2134b, a mini-Neptune a few gigayears old. The average in-transit absorption spectrum shows a peak of 0.37% ± 0.05% and an equivalent width of W avg = 3.3 ± 0.3 mÅ. Among all planets with helium detections, TOI 2134b is the only mature mini-Neptune, has the smallest helium signal, an…

2023 The Astrophysical Journal
XMM-Newton 18
High-angular-resolution NIR view of the Orion Bar revealed by Keck/NIRC2
DOI: 10.1051/0004-6361/202244034 Bibcode: 2023A&A...673A.149H

Le Gal, Romane; Bron, Emeric; Wolfire, Mark G. +7 more

Context. Nearby photo-dissociation regions (PDRs), where the gas and dust are heated by the far-ultraviolet (FUV) irradiation emitted from stars, are ideal templates with which to study the main stellar feedback processes.
Aims: With this study, we aim to probe the detailed structures at the interfaces between ionized, atomic, and molecular g…

2023 Astronomy and Astrophysics
Gaia Herschel eHST 18
Photometric and structural parameters of newly discovered nuclear star clusters in Local Volume galaxies
DOI: 10.1093/mnras/stad220 Bibcode: 2023MNRAS.520.4664H

Neumayer, Nadine; Greene, Jenny E.; Seth, Anil C. +2 more

We use high-resolution Hubble Space Telescope imaging data of dwarf galaxies in the Local Volume ($\lesssim {11}\, \mathrm{Mpc}$) to parameterize 19 newly discovered nuclear star clusters (NSCs). Most of the clusters have stellar masses of $M_{\star }^{\mathrm{nsc}} \lesssim 10^{6}{\, {\rm M}_{\odot }}$ and compare to Galactic globular clusters in…

2023 Monthly Notices of the Royal Astronomical Society
eHST 18
The Ionizing Spectra of Extremely Metal-poor O Stars: Constraints from the Only H II Region in Leo P
DOI: 10.3847/1538-4357/aca896 Bibcode: 2023ApJ...943...65T

McQuinn, Kristen B. W.; Chisholm, John; Berg, Danielle A. +1 more

Metal-poor, star-forming dwarf galaxies produce extreme nebular emission and likely played a major role in cosmic reionization. Yet, determining their contribution to the high-redshift ionizing photon budget is hampered by the lack of observations constraining the ionizing spectra of individual massive stars more metal-poor than the Magellanic Clo…

2023 The Astrophysical Journal
eHST 18
Evidence of extended cold molecular gas and dust haloes around z ∼ 2.3 extremely red quasars with ALMA
DOI: 10.1093/mnras/stac3787 Bibcode: 2023MNRAS.519.5246S

Maiolino, R.; Carniani, S.; Scholtz, J. +1 more

Large-scale outflows are believed to be an important mechanism in the evolution of galaxies. We can determine the impact of these outflows by studying either current galaxy outflows and their effect in the galaxy or by studying the effect of past outflows on the gas surrounding the galaxy. In this work, we examine the CO(7-6), [C I] ($^{3} \rm P_{…

2023 Monthly Notices of the Royal Astronomical Society
eHST 18
The geometric albedo of the hot Jupiter HD 189733b measured with CHEOPS
DOI: 10.1051/0004-6361/202245016 Bibcode: 2023A&A...672A..24K

Guterman, P.; Alonso, R.; Deleuil, M. +84 more

Context. Measurements of the occultation of an exoplanet at visible wavelengths allow us to determine the reflective properties of a planetary atmosphere. The observed occultation depth can be translated into a geometric albedo. This in turn aids in characterising the structure and composition of an atmosphere by providing additional information o…

2023 Astronomy and Astrophysics
CHEOPS eHST 18