Search Publications

Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815
DOI: 10.1051/0004-6361/202348678 Bibcode: 2024A&A...685A...5P

Helling, Christiane; Hellier, Coel; Charnoz, Sébastien +130 more

We present the discovery and characterization of two warm mini-Neptunes transiting the K3V star TOI-815 in a K–M binary system. Analysis of its spectra and rotation period reveal the star to be young, with an age of 200‑200+400 Myr. TOI-8l5b has a 11.2-day period and a radius of 2.94 ± 0.05 R with transits observe…

2024 Astronomy and Astrophysics
CHEOPS Gaia 4
Characterization of starspots on a young M-dwarf K2-25: multiband observations of stellar photometric variability and planetary transits
DOI: 10.1093/mnras/stae841 Bibcode: 2024MNRAS.530..167M

Ikuta, Kai; Tamura, Motohide; Livingston, John H. +13 more

Detailed atmospheric characterization of exoplanets by transmission spectroscopy requires careful consideration of stellar surface inhomogeneities induced by star-spots. This effect is particularly problematic for planetary systems around M-dwarfs, and their spot properties are not fully understood. We investigated the stellar activity of the youn…

2024 Monthly Notices of the Royal Astronomical Society
Gaia 4
Ly α emission strength and stellar properties of faint galaxies from 5 < z < 8.2
DOI: 10.1093/mnras/stae1339 Bibcode: 2024MNRAS.531.2998B

Pentericci, Laura; Treu, Tommaso; Jones, Gareth C. +6 more

We present a study on stellar properties of Lyman-alpha (Ly α) emitters at 5 < z < 8.2. We use 247 photometrically selected, lensed, high-redshift, low-luminosity galaxy candidates with spectroscopic follow-up. Of these, 38 are confirmed spectroscopically to be between 5 < z < 8.2 via detection of Ly α. For each galaxy and candidate, w…

2024 Monthly Notices of the Royal Astronomical Society
eHST 4
A Comprehensive Study of Open Cluster Chemical Homogeneity Using APOGEE and Milky Way Mapper Abundances
DOI: 10.3847/1538-4357/ad78e1 Bibcode: 2024ApJ...975...89S

Cunha, Katia; Souto, Diogo; Tayar, Jamie +4 more

Stars in an open cluster are assumed to have formed from a broadly homogeneous distribution of gas, implying that they should be chemically homogeneous. Quantifying the level to which open clusters are chemically homogeneous can therefore tell us about interstellar medium pollution and gas mixing in progenitor molecular clouds. Using Sloan Digital…

2024 The Astrophysical Journal
Gaia 4
Spatial Variations of Dust Opacity and Grain Growth in Dark Clouds: L1689, L1709, and L1712
DOI: 10.3847/1538-4357/ad2a59 Bibcode: 2024ApJ...965...29L

Chen, Xi; Jiang, Biwei; Zhao, He +2 more

The far-infrared (FIR) opacity of dust in dark clouds within the Ophiuchus molecular cloud is investigated through multiwavelength infrared observations from UKIDSS, Spitzer, and Herschel. Employing the infrared color excess technique with both near-infrared and mid-infrared photometric data, a high-resolution extinction map in the K band (A

2024 The Astrophysical Journal
Herschel 4
NGTS-30b/TOI-4862b: An 1 Gyr old 98-day transiting warm Jupiter
DOI: 10.1051/0004-6361/202449307 Bibcode: 2024A&A...686A.230B

Bouchy, F.; Alves, D. R.; Henning, T. +63 more

Context. Long-period transiting exoplanets bridge the gap between the bulk of transit- and Doppler-based exoplanet discoveries, providing key insights into the formation and evolution of planetary systems. The wider separation between these planets and their host stars results in the exoplanets typically experiencing less radiation from their host…

2024 Astronomy and Astrophysics
Gaia 4
Ionospheric irregularities at Jupiter observed by JWST
DOI: 10.1038/s41550-024-02305-9 Bibcode: 2024NatAs...8.1000M

Hueso, R.; Sánchez-Lavega, A.; Fletcher, L. N. +22 more

Jupiter's upper atmosphere is composed of a neutral thermosphere and charged ionosphere. In the latter, the dominant molecular ion H3+ emits in the near-infrared, allowing for the remote exploration of the physical properties of the upper atmosphere. However, the Jovian low-latitude ionosphere remains largely unexplored becau…

2024 Nature Astronomy
JWST 4
ALMA-LEGUS. II. The Influence of Subgalactic Environments on Molecular Cloud Properties
DOI: 10.3847/1538-4357/ad198a Bibcode: 2024ApJ...964...13F

Grebel, Eva K.; Smith, Linda J.; Aloisi, Alessandra +24 more

We compare the molecular cloud properties in subgalactic regions of two galaxies, barred spiral NGC 1313, which is forming many massive clusters, and flocculent spiral NGC 7793, which is forming significantly fewer massive clusters despite having a similar star formation rate to NGC 1313. We find that there are larger variations in cloud propertie…

2024 The Astrophysical Journal
eHST 4
Spatially correlated stellar accretion in the Lupus star-forming region: Evidence for ongoing infall from the interstellar medium
DOI: 10.1051/0004-6361/202452120 Bibcode: 2024A&A...691A.169W

Benisty, Myriam; Manara, Carlo F.; Gupta, Aashish +1 more

Context. Growing evidence suggests that protoplanetary discs may be influenced by late stage infall from the interstellar medium (ISM). It remains unclear the degree to which infall shapes disc populations at ages ≳1 Myr. Aims. We explored possible spatial correlations between stellar accretion rates in the Lupus star-forming region, which would s…

2024 Astronomy and Astrophysics
Gaia 4
Braving the Storm: Quantifying Disk-wide Ionized Outflows in the Large Magellanic Cloud with ULLYSES
DOI: 10.3847/1538-4357/ad64d2 Bibcode: 2024ApJ...974...22Z

Choi, Yumi; Olsen, Knut; Roman-Duval, Julia +11 more

The Large Magellanic Cloud (LMC) is home to many H II regions, which may lead to significant outflows. We examine the LMC's multiphase gas (T∼104-5 K) in H I, S II, Si IV, and C IV using 110 stellar sight lines from the Hubble Space Telescope's Ultraviolet Legacy Library of Young Stars as Essential Standards program. We develop a contin…

2024 The Astrophysical Journal
eHST 4