Search Publications

JWST/NIRCam detections of dusty subsolar-mass young stellar objects in the Small Magellanic Cloud
DOI: 10.1038/s41550-023-01945-7 Bibcode: 2023NatAs...7..694J

Hirschauer, Alec S.; Fahrion, Katja; Lenkić, Laura +23 more

Low-mass stars are the most numerous stellar objects in the Universe. Before the James Webb Space Telescope (JWST), we had limited knowledge of how planetary systems around low-mass stars could form at subsolar metallicities. Here we present JWST observations of NGC 346, a star-forming region in the metal-poor Small Magellanic Cloud, revealing a s…

2023 Nature Astronomy
eHST JWST 19
Hot Subdwarf Stars Identified in LAMOST DR8 with Single-lined and Composite Spectra
DOI: 10.3847/1538-4357/aca542 Bibcode: 2023ApJ...942..109L

Németh, Péter; Zhao, Jingkun; Hu, Ke +6 more

A total of 222 hot subdwarf stars were identified with LAMOST DR8 spectra, among which 131 stars show composite spectra and have been decomposed, while 91 stars present single-lined spectra. Atmospheric parameters of all sample stars were obtained by fitting hydrogen (H) and helium (He) line profiles with synthetic spectra. Two long-period composi…

2023 The Astrophysical Journal
Gaia 19
Flashlights: an off-caustic lensed star at redshift z = 1.26 in Abell 370
DOI: 10.1093/mnras/stad869 Bibcode: 2023MNRAS.521.5224M

Broadhurst, Tom; Filippenko, Alexei V.; Kelly, Patrick L. +11 more

We report the discovery of a transient seen in a strongly lensed arc at redshift zs = 1.2567 in Hubble Space Telescope imaging of the Abell 370 galaxy cluster. The transient is detected at 29.51 ± 0.14 AB mag in a WFC3/UVIS F200LP difference image made using observations from two different epochs, obtained in the framework of the Flashl…

2023 Monthly Notices of the Royal Astronomical Society
eHST 19
Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4b, and the transit-timing variations of HD 97658 b
DOI: 10.1051/0004-6361/202244529 Bibcode: 2023A&A...669A.124H

Alonso, R.; Deleuil, M.; Erikson, A. +87 more

Context. Tidal orbital decay is suspected to occur for hot Jupiters in particular, with the only observationally confirmed case of this being WASP-12b. By examining this effect, information on the properties of the host star can be obtained using the so-called stellar modified tidal quality factor Q*', which describes the eff…

2023 Astronomy and Astrophysics
CHEOPS eHST 19
Polarisation of decayless kink oscillations of solar coronal loops
DOI: 10.1038/s41467-023-41029-8 Bibcode: 2023NatCo..14.5298Z

Antolin, Patrick; Berghmans, David; Chitta, Lakshmi Pradeep +4 more

Decayless kink oscillations of plasma loops in the solar corona may contain an answer to the enigmatic problem of solar and stellar coronal heating. The polarisation of the oscillations gives us a unique information about their excitation mechanisms and energy supply. However, unambiguous determination of the polarisation has remained elusive. Her…

2023 Nature Communications
SolarOrbiter 19
TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf
DOI: 10.1093/mnras/stad306 Bibcode: 2023MNRAS.520.3649H

Barclay, Thomas; Hellier, Coel; Triaud, Amaury H. M. J. +137 more

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (~200 mas yr-1), low metallicity ([Fe/H]≈-0.28) K-dwarf with a mass of 0.68 ± 0.05 M and a radius of 0.67 ± 0.01 R. We obtain photometri…

2023 Monthly Notices of the Royal Astronomical Society
Gaia 19
Digging into the Galactic Bulge: Stellar Population and Structure of the Poorly Studied Cluster NGC 6316
DOI: 10.3847/1538-4357/aca9ce Bibcode: 2023ApJ...942..104D

Cadelano, Mario; Pallanca, Cristina; Ferraro, Francesco R. +2 more

High-resolution Hubble Space Telescope optical observations have been used to analyze the stellar population and the structure of the poorly investigated bulge globular cluster NGC 6316. We constructed the first high-resolution reddening map in the cluster direction, which allowed us to correct the evolutionary sequences in the color-magnitude dia…

2023 The Astrophysical Journal
Gaia eHST 19
Gaia Data Release 3. Stellar chromospheric activity and mass accretion from Ca II IRT observed by the Radial Velocity Spectrometer
DOI: 10.1051/0004-6361/202244156 Bibcode: 2023A&A...674A..30L

Hatzidimitriou, D.; Marshall, D. J.; Andretta, V. +82 more

Context. The Gaia Radial Velocity Spectrometer (RVS) provides the unique opportunity of a spectroscopic analysis of millions of stars at medium resolution (λ/Δλ ∼ 11 500) in the near-infrared (845−872 nm). This wavelength range includes the Ca II infrared triplet (IRT) at 850.03, 854.44, and 866.45 nm, which is a good indicator of magnetic activit…

2023 Astronomy and Astrophysics
Gaia 19
A shared accretion instability for black holes and neutron stars
DOI: 10.1038/s41586-022-05648-3 Bibcode: 2023Natur.615...45V

Altamirano, D.; Belloni, T.; Degenaar, N. +20 more

Accretion disks around compact objects are expected to enter an unstable phase at high luminosity1. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion and refilling of the inner disk on short timescales2. Such a scenario, however, has onl…

2023 Nature
eHST 19
ODIN: Where Do Lyα Blobs Live? Contextualizing Blob Environments within Large-scale Structure
DOI: 10.3847/1538-4357/acd341 Bibcode: 2023ApJ...951..119R

Dey, Arjun; Gronwall, Caryl; Jeong, Woong-Seob +16 more

While many Lyα blobs (LABs) are found in and around several well-known protoclusters at high redshift, how they trace the underlying large-scale structure is still poorly understood. In this work, we utilize 5352 Lyα emitters (LAEs) and 129 LABs at z = 3.1 identified over a ~9.5 deg2 area in early data from the ongoing One-hundred-deg

2023 The Astrophysical Journal
Gaia 19